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1
Wänstrand, Olle. "Wear resistant low friction coatings for machine elements." Doctoral thesis, Uppsala University, Department of Materials Science, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1084.
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By the introduction of machine elements made of light metals, e.g. Al or Mg alloys, which are coated with a material providing high wear resistance and low friction coefficient, both economical and environmental benefits can be gained. A high resistance against wear results in increased lifetime and lower costs for spare parts and maintenance. This also means fewer production stops and less machine downtime. Moreover, a vehicle of lower weight and with reduced friction losses will consume less fuel.
The light metal alloys display low hardness and elastic modulus and in addition they have a high tendency to stick to the countersurface in sliding contact. Hence, to be used in tribologically demanding applications, they must be coated with a material providing low friction and wear. Due to the thin and brittle nature of the available coatings an intermediate load-carrying layer has to be introduced to protect the base material from large deformations and the brittle surface coating from cracking.
In this thesis both experiments and theoretical simulations has shown that the load-carrying layer between the soft and compliant base material and the thin brittle coating should have high elastic modulus and hardness as well as a for the contact situation sufficient thickness.
A number of vapour deposited coatings have been investigated regarding their tribological behaviour with special emphasis on the mechanisms providing low friction. When sliding against steel, it was found that carbon-rich coatings show much lower friction and wear of the countersurface than nitrogen-rich coatings. The explanation is that steel has a tendency to stick to nitrogen-rich coatings, leading to steel against steel contact, but not to carbon-rich coatings. Another explanation is that material is transferred from a carbon-rich coating to the steel and this gives an easily sheared contact with low friction coefficient.
2
Lindholm, Per. "Wear resistant low friction coatings for engine components." Doctoral thesis, Stockholm, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-54.
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Scholvin, Dirk. "Wear resistant nanostructured diamondlike carbon coatings on Ti-alloy." Thesis, Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180353/unrestricted/scholvin%5fdirk%5f200312%5fms.pdf.
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4
Mower, D. Adam. "An Investigation of Wear-Resistant Coatings on an A390 Die-Cast Aluminum Substrate." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1765.pdf.
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Belov, D. S., A. O. Volkhonsky, Blinkov I. V, E. A. Skryleva, and J. Michalski. "Multilayer Nanostructured Wear-Resistant Coatings with Increased Thermal Stability, Adapted to Varying Friction Conditions." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35318.
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The work covers studying of influence of indexes of an ion-plasma vacuum-arc deposition method to the
structure, composition and properties of Ti-Al-N/Zr-Nb-N/Cr-N multilayer nanostructured coatings (MNC).
The average crystallites size within the layers is about 5-10 nm. Received coatings are featured by absence of any
change in the composition and properties after heating up to 1000 ºС, the coatings hardness is up to
36,6GPa, Young's modulus of elasticity is up to 580 GPa, plastic work of deformation is up to 64 %, adhesive
strength is about 100 N and coefficient of friction is 0,45.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35318
6
Wu, Wenwen. "Development and characterisation of novel low-friction wear-resistant multiplayer nanocomposite CrAlTiCN coatings." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1371/.
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The present investigation has been focused on the design, deposition and characterisation of novel low-friction, wear-resistant multilayer nanocomposite CrAlTiCN coatings. Systematic materials characterisation and property evaluation were conducted on the as-deposited and oxidation-tested CrAlTiCN coatings, and the results are presented and discussed. It is possible to generate novel CrAlTiCN coatings with the carbon content up to 24.34 at% by closed-field unbalanced magnetron sputtering of graphite target. The microstructure of the CrAlTiCN coatings mainly depends on their carbon content. When the carbon content is low, carbon atoms are mainly dissolved in the fcc metastable phase (Cr, Al, Ti) (C, N); when the carbon content is high, the major carbon atoms will form amorphous carbon with a C-C bond state and in a sp\(^2\) dominated graphitic environment. Both the hardness and brittleness of CrAlTiCN coatings reduce with increasing the carbon content. When tested at room temperature under unidirectional sliding conditions, the friction coefficient and wear of the CrAlTiCN coatings decrease with the carbon content, and the thermal stability of CrAlTiCN coatings is similar to the CrAlTiN coating but better than graphite-like carbon coatings. The good performance of the new CrAlTiCN coatings can be attributed to the optimised design of the coating system: the Cr/Al for oxidation resistance, the amorphous C for lowfriction and the multi-layered nano-composite microstructure for high toughness.
7
Amiriyan, Mahdi. "Development of ceramic reinforced iron aluminide based composite coatings for wear resistant applications." Doctoral thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/35012.
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Les composés intermétalliques Fe₃Al et leurs revêtements composites sont des matériaux structuraux potentiels pour des applications tribologiques. Parmi les composites, ceux obtenus par broyage mécanique à haute énergie possèdent plusieurs avantages, en particulier une fabrication rentable. Le broyage à billes à haute énergie permet également une large gamme de fraction volumique des particules de renforcement. Dans cette recherche, Nous avons préparé des revêtements composites à matrice d'aluminiure de fer, basés sur la composition chimique de Fe₃Al avec des particules de renforcement de TiC et de TiB₂ en utilisant un broyeur à billes à haute énergie et déposé par la technique HVOF (High Velocity Oxy Fuel). L'effet des paramètres de traitement tels que la durée du broyage et le traitement thermique subséquent sur les la matière première destinés à la projection par HVOF a été étudié. Les paramètres de traitement ont joué des rôles importants sur la poudre composite et par la suite sur la microstructure, les propriétés mécaniques et tribologiques des revêtements. Le but de la première phase expérimentale de ce travail était d'étudier l'effet des particules de TiC in situ sur la microstructure, le comportement mécanique et tribologique des revêtements de Fe₃Al déposés par HVOF. Dans cette étape, des poudres composites Fe₃Al / TiC avec différentes quantités de carbure de titane ont été produites par broyage à haute énergie. Un mélange de Fe₃Al-Ti-C a été broyé pendant 6 h suivi d'un traitement thermique à 1000 °C pendant 2 h sous vide poussé. Des revêtements composites d'aluminure de fer renforcés au TiC in situ ont été préparés pour améliorer la dureté Vickers et la résistance à l'usure des intermétalliques de Fe₃Al. Les revêtements composites consistent principalement en une phase de TiC uniformément dispersée dans des lamelles de la matrice de Fe₃Al. Les revêtements composites ont montré une dureté Vickers croissante avec l’augmentation de la quantité de TiC, allant jusqu'à 70 % en moles de TiC. La résistance à l'usure par glissement à sec des revêtements a été augmentée avec l'addition de particules de TiC formées in situ. Les revêtements composites de Fe₃Al déposés par HVOF avec des renforts en TiC de 50 % et 70 % en moles présentaient une excellente résistance à l'usure par glissement. Le mécanisme d'usure dominant de ces revêtements était l'abrasion et l'oxydation. Dans une autre étape de ce travail, des poudres composites de Fe₃Al-TiB₂ avec deux quantités différentes de borure ont été produites par le dépôt par high Velocity Oxy Fuel (HVOF) sur un substrat en acier. Les revêtements composites consistaient principalement en une phase de TiB₂ pré-synthétisée et uniformément dispersée dans des lamelles de la matrice de Fe₃Al. Il a été montré qu'en augmentant la fraction volumique du TiB₂, la dureté Vickers et la résistance à l'usure par glissement des revêtements contre le contre-corps en alumine (6,33 mm de diamètre) étaient augmentées. L'augmentation de la résistance à l'usure était censée être liée à l'amélioration de la dureté, qui à son tour est due à la présence de particules de TiB₂ dans la matrice Fe₃Al. Le taux d'usure de glissement des revêtements a augmenté pour atteindre un maximum lorsque la vitesse de glissement augmente, puis il a diminué avec l'augmentation supplémentaire de la vitesse de glissement. Les analyses chimiques des surfaces usées ont montré que des vitesses de glissement plus élevées entraînent une oxydation plus élevée de la surface, probablement en raison de la température locale plus élevée. Une telle couche d'oxyde semble agir comme une barrière entre deux corps coulissants, diminuant ainsi le taux d'usure.Fe₃Al intermetallic compounds and their composite coatings are potential structural materials for tribological applications. High-energy ball milled powders possess several advantages, especially cost-effective fabrication and lower cost of reinforcement. High-energy ball mill also allows for a wide range of reinforcement volume fraction. In this research, Iron Aluminide matrix composite coatings based on Fe₃Al chemical composition with TiC and TiB₂ particles were prepared using a high-energy ball mill and deposited via the High Velocity Oxy Fuel (HVOF) technique. The effect of processing parameters such as ball milling duration and subsequent heat treatment soaking time and temperature on the phases of products as a feed stock for the HVOF gun was studied. The processing parameters played important roles on the microstructure, mechanical and tribological properties of the coatings. The aim of the first experimental stage of this work was to study the effect of in-situ TiC particles on microstructure, mechanical and tribological behavior of HVOF deposited Fe₃Al coatings. In this stage Fe₃Al/TiC composite powders with different carbide quantities were produced via high-energy ball milling of Fe₃Al-Ti-C system for 6 h followed by heat treatment at 1000 °C for 2 h under high vacuum. In-situ TiC-reinforced iron aluminide composite coatings were prepared to improve the Vickers hardness and wear resistance of Fe₃Al intermetallics. The composite coatings mainly consist of a TiC phase uniformly dispersed within lamellae of the Fe₃Al matrix. The composite coatings showed increasing Vickers hardness with increasing TiC content up to 70 mol% TiC. The dry sliding wear resistance of coatings was increased with the addition of in-situ formed TiC particles. HVOF deposited Fe₃Al composite coatings with 50 and 70 mol% TiC reinforcements exhibited excellent sliding wear resistance. The dominant wear mechanism in those coatings was abrasion and oxidation. In another stage of this work Fe₃Al-TiB2 composite powders with two different boride quantities were produced by the high Velocity Oxy Fuel (HVOF) spray deposition on a steel substrate. The composite coatings mainly consisted of a TiB₂ phase uniformly dispersed within lamellae of the Fe₃Al matrix. It was shown that by increasing the volume fraction of TiB₂ both the Vickers hardness and sliding wear resistance of the coatings against alumina counterbody (6.33 mm in diameter) were increased. The increase of wear resistance was believed to be related to the hardness enhancement, which, in turn, is due to the presence of TiB₂ particles within the Fe3Al matrix. The sliding wear rate of the coatings increased to reach a maximum as the sliding speed increases, and then it decreased with further increase of the sliding speed. The chemical analyses of the worn surfaces showed that higher sliding speeds result in higher oxidation of the surface, most likely due to the higher local temperature. Such an oxide layer seems to act as a barrier between two sliding bodies, thus decreasing the wear rate.
8
Ahrens, Rebecca Lynn. "Modification of plasma sprayed wear and corrosion resistant coatings by high-density infrared heating." [Ames, Iowa : Iowa State University], 2007.
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9
Shreeram, Devesh Dadhich. "Development of Wear and Corrosion Resistant Nickel Based Coatings Through Pulse Reverse Current (PRC) Electrodeposition Process." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1509839587682532.
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Spike, M., and R. Miles. "The fundamental thermodynamic relation on contact surfaces of multicomponent nanocomposite coatings with hierarchical and adaptive behavior." Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/47079.
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The increasing demands of modern engineering have spawned the development of new advanced materials for use. The development of advanced materials can be considered to be a typical problem of engineering optimization. In this process, an integrated engineering–physical approach is used to develop novel wear-resistant materials. Until now only a limited amount of investigations have been performed on the progression of the self-organization process during friction. Moreover studies made so far focused mostly on the characteristics of tribo-films.
11
Горбачова, Т. Ю., Тетяна Павлівна Говорун, Татьяна Павловна Говорун, and Tetiana Pavlivna Hovorun. "Зносостійкі покриття для ріжучих інструментів на основі Mo, Cr та N." Thesis, Сумський державний університет, 2017. http://essuir.sumdu.edu.ua/handle/123456789/62401.
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На сьогоднішній день активно розробляються і застосовуються в
промисловості нові матеріали для ріжучих інструментів. Крім виробництва
нових видів твердих швидкорізальних сталей і сплавів, велика увага
приділяється захисту і зміцненню поверхні інструменту різними покриттями:
від зношування, для покращення корозійної стійкості, з метою збереження
його геометрії для більш швидкісних режимів обробки материалів. Одним з
основних напрямків в цій галузі є розробка зносостійких покриттів і їх
нанесення на ріжучі інструменти [1]. Експериментально доведено факт, що
покриття здатні підвищити ефективність інструменту і поліпшити
властивості оброблюваної поверхні.
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Pererva, V. I., T. Y. Gorbacheva, Тетяна Павлівна Говорун, Татьяна Павловна Говорун, and Tetiana Pavlivna Hovorun. "Multilayer wearresistant coverages based on mon/crn, tin/zrn for wares of mechanical engineering and cutting instrument." Thesis, Sumy State University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/66645.
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Today, the rapid development of the industry uses new materials for cutting
tools. Besides the production of new types of solid high-speed steel and alloys,
focuses on strengthening and surface protection products different surfaces. One of
the main trends in this area is to develop wear-resistant coatings and their
application to cutting tools [1], watches with PVD-coated, glasses with gold frames
and others. This is made possible by the application as coating materials based on
Ti and Zr, Mo and Cr on the use of technology in active gas mixture of nitrogen N
[2].
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Radionovienė, Jolita. "Vibromechaninio apdirbimo įtakos Cr-Ni-Co dangų savybėms tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080930_090440-62595.
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Daugelis svarbių konstrukcijų po tam tikro naudojimo laiko, veikiant aplinkai, nebetinka naudoti ir, svarbiausia, gali suirti ir sukelti įvairias avarines situacijas. Norint pailginti detalių ilgaamžiškumą yra naudojamos apsauginės dangos, kurios garantuoja gaminio patikimumą ir kokybę. Tyrimais siekiama išsiaiškinti, ar vibromechaninis apdirbimas terminio purškimo metu turi įtakos Cr-Ni-Co dangos savybėms. Šiuo atveju, siekiant užnešti paviršiaus dangą ant pagrindo yra naudojamas terminio purškimo būdas, t. y. išlydytą purškiamą medžiagą dujų srautas suskaido į smulkius lašelius (atomizuoja), įgreitina juos ir didele kinetine energija bloškia į substrato paviršių. Purškiamas Eutalloy 10611 miltelių mišinys, kuriame yra Cr, Ni, Co ir tankių, kietų volframo karbidų dalelių, suteikiančių dangai didelį atsparumą dilimui. Tyrimų metu nustatyta, kad vibromechaninis apdirbimas turi įtakos tokioms dangos savybėms, kaip adhezija, porėtumas, mikrokietumas ir išdilimas.A lot of important constructions are not exploitable any more, because of environmental influence and, even worse, can cause emergency situations after decomposition. Protective coatings are used in order to extend the durability and guarantee high quality of component parts. The objective of this research is to verify if vibromechanical treatment during thermal spraying has any influence on characteristics of Cr-Ni-Co coatings. Thermal spraying is used in order to coat a surface in this case, i.e. gas flow dissolves the sprayed molten material into small drops (atomizes), accelerates and flings it on a surface with large amount of kinetic energy. Eutalloy 10611 powder compound is being sprayed, which contains Cr, Ni, Co and dense, hard wolfram carbide particles, giving the coating good attrition resistance. In accordance with experimental data, it is determined, that vibromechanical traetment has particular influence on adhesive, porous, microhardness and attrition properties of coating, with various vibromechanical modes applyed.
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Elrikh, Axelle. "Revêtement anti-usure déposé par projection plasma sur matériaux composites fibres de carbones/matrice époxy pour applications aéronautiques." Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0131/document.
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Les matériaux composites à matrice polymères renforcés aux fibres de carbone (PRFC) sont de plus en plus utilisés dans les avions, en raison de leur faible densité et de leurs propriétés mécaniques comparables aux alliages généralement utilisés. Ils sont cependant sensibles aux impacts répétés des particules solides et liquides intervenant au cours du cycle de vol d’un avion, et nécessitent d’être protégés. Cette thèse est inscrite dans ce contexte de protection des PRFC, plus particulièrement ceux à matrice époxy, par le biais de dépôts anti-usure réalisés par projection plasma sous air. De tels recherche ont été menées auparavant avec pour résultats des dépôts céramique et métallique peu adhérents, sur des composites fortement endommagés par le procédé. Les travaux de cette thèse ont donc été organisés autour de deux objectifs :- Objectif fondamental : comprendre les interactions entre les particules fondues et le composite. Grâce à une étude multiéchelles d’impacts de gouttes sur le composite, la résine époxy et sa dégradation thermique ont été identifiés comme responsable de la mauvaise adhérence des dépôts projetés par plasma sur les PRFC.- Objectif expérimental. Déterminer la faisabilité de réaliser un revêtement anti-usure par projection plasma sur PRFC. Deux traitements de surface avant dépôt ont été choisis puis testés, en conditions d’impacts de particules isolées et de formation de dépôts. Des dépôts d’alumine ont pu être obtenus, sans dégradation thermique ou mécanique du compositeCarbon fiber reinforced polymers (CFRP) are increasingly used in aircraft structures, due to their good strength to weight ratio. However, they are more sensitive to the impacts of solid and liquid particles, occurring during the aircraft flight cycle, and thus need to be protected. This work focuses on the protection of carbon fiber reinforced epoxy by air plasma spraying (APS). Numerous studies have been conducted on applying such coatings, but the obtained metallic and ceramic coatings show poor adhesion strength, and the underlying composite material is damaged by the APS process. This PhD is organized around two objectives:- Fundamental objective: understand the interactions between molten particles and the composite. A multi-scale study of droplets impacts on the composite led to identify the epoxy resin as responsible for the poor adhesion strength of air plasma sprayed coatings on CFRPs.- Experimental objective: determine the feasibility of producing an anti-wear coating by plasma spraying on CFRP. Two surface treatments prior to APS were chosen and tested in single particles impacts and coating formation. Alumina coatings have been obtained, without thermal or mechanical degradation of the underlying composite
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Symonds, Nicola. "Polymeric coatings for wireline wear and impact resistance." Thesis, University of Southampton, 2000. https://eprints.soton.ac.uk/341034/.
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Polymeric coatings find applications in downhole water injector tubulars, protecting the inner surfaces from corrosion. Although these predominately epoxy-based coatings resist the harsh temperatures and pressures associated with a working injector, they are currently failing when exposed to mechanical damage. The mechanical damage takes the form of impact and wireline wear inflicted by the downhole 'tools' required in the maintenance of the injectors. In this work, experimental techniques have been developed for the successful direct observation of the impact and wireline wear damage mechanisms. The work has taken two concurrent paths, one investigating the abrasive wear range of supplied polymeric coatings utilising a pin-on-disc rig, the second studying the same coatings under impact conditions for which a specialised rig was designed and built. By comparing the recorded failure mechanism to physical properties of the coatings, relationships were found which led to recommendations initiating compositional changes to the coatings. One of the most significant findings of the work was that although the downhole coatings industry has spent many years developing and marketing thermoset based coatings, the under-utilised thermoplastic-based coatings appear to offer a 'better' solution to the problem. Unlike the modified epoxy coatings, it was shown that nylon-based coatings resist both wireline wear and impact damage without compromising the corrosion barrier properties of the coatings.
16
Lam, Wayne Pui-Wing. "Assessment of wear resistance of tin and tin alloy coatings." Thesis, Brunel University, 2007. http://bura.brunel.ac.uk/handle/2438/5229.
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Tin alloy coatings have traditionally been used as corrosion resistant bamens due to their inert nature and comprehensive coverage, and have seldom been considered in physically demanding applications, such as wear resistant coatings owing to misconceptions associated with the soft nature of tin metal. The alloying of tin with copper has already been shown to significantly increase its mechanical properties, as demonstrated by the adoption of tin-copper alloys for use as bearing materials. Unfortunately, its cyanide plating technology makes tin-copper environmentally unsustainable, whilst the process requires constant regulation and monitoring, and there are disposal costs associated with the cyanide waste products. The tin-nickel alloy, however, can be produced with minimal supervision and its plating process uses less harmful precursors, making it an alternative consideration. The research documented in this thesis assesses this increase by quantifying the resistance of tin, tin-nickel and tin-copper coatings to removal from sliding wear. As tin is a soft material and behaves dissimilarly to conventional coatings in a sliding wear environment, traditional wear assessment techniques are not appropriate. A novel approach is therefore devised and implemented, and this involves the continually monitoring the effect of damage introduced to the surface of the tin and tin alloy coatings, from an abrading ceramic ball. Using an elemental detection tool, it is possible to analyse wear scars that exhibit progressively depleted coating material, by identifying the underlying substrate material as it becomes exposed. In this way, it is possible to quantify the improvements made to tin from alloying with nickel and copper. The large volume of data acquired from this research is presented in a matrix format to enable simultaneous depiction of multiple parameters, and to allow quick and easy interpretation. The tin-nickel coating is found to be comparable to tin-copper in terms of resistance to removal. Despite tin-copper being slightly superior over the range of test conditions used, tin-nickel as been shown to be an environmentally friendly and cost effective alternative coating alloy to tin-copper.
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Sudin, Mustafar Bin. "Studies into duplex electroless nickel - PAPVD coatings for wear and corrosion resistance." Thesis, University of Hull, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321123.
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Tuaweri, Johnnie T. "Zinc and zinc alloy composite coatings for corrosion protection and wear resistance." Thesis, Loughborough University, 2005. https://dspace.lboro.ac.uk/2134/10888.
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Zinc and its alloys are among the most widely utilised metallic coatings for the sacrificial protection of steel. Although excellent in this mode of protection, these coatings are often less durable when subjected to environments of combined wear and corrosion due to their intrinsic relative softness and ductility. A possible and fast growing way of improving the durability of these coating is by the codeposition of inert particles into the zinc and zinc-alloy matrix. The main aim of this research was therefore to improve the durability of zinc and zinc-nickel coatings by the incorporation of inert particles via electrolytic codeposition methods. The first five chapters of this thesis comprise literature review on the electrodeposition of zinc, its alloys and composite electrodeposition in general. A major part of which was dedicated to the review of various conventional methods and parameters such as current density, agitation, temperature, solution composition, bath additives and pH usually investigated in electrodeposition. The experimental work was principally based on DC electrodeposition and was aimed at understanding the deposition behaviour of zinc and zinc-nickel electrodeposition baths, conditions which influence them and solution compatibility to the introduction of silica particles. A systematic study on the deposition behaviour of both zinc/silica and zinc-nickel/silica composite baths was carried out with particular interest on the rate of particle incorporation and the influence of particles on zinc-nickel alloy deposition. The complimentary codeposition behaviour of the nickel and silica particles was observed. The influence of bath additives such as N,N Dimethyldodecylamine (NND) and sodium nitrate on the rate of silica incorporation was also studied. Both additives were found to improve the rate of particle incorporation for the zinc/silica. The morphologies and compositions of the coatings were analysed with the use of SEM and FEGSEM. Corrosion performance studies were carried out in a neutral salt spray chamber and linear polarisation resistance methods used to determine barrier corrosion properties of the coatings. Anodic polarisation studies were also carried out. The results show an improvement in the corrosion performance of these coatings with the addition of silica particles Reciprocating wear tests were used to determine the wear behaviour of the coatings in terms of weight loss. Improvement in wear resistance was not observed in the zinc/silica coatings probably due to the high content of silica in the coatings. Lower silica contents may be required for the desired improvements. However, there were obvious improvements in the wear behaviour of the zinc-nickel/silica coatings due to the presence of the silica particles.
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Löbel, Martin, Thomas Lindner, Thomas Mehner, and Thomas Lampke. "Microstructure and Wear Resistance of AlCoCrFeNiTi High-Entropy Alloy Coatings Produced by HVOF." Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-230210.
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The investigation of high-entropy alloys (HEAs) has revealed many promising properties. HEAs with a high share of Al and Ti are suitable for the formation of lightweight materials. Investigations of the alloy system AlCoCrFeNiTi showed high strength, hardness, ductility, and wear resistance, which makes this special alloy interesting for surface engineering and particularly for thermal spray technology. In this study, the suitability of inert gas-atomised HEA powder for high-velocity-oxygen-fuel (HVOF) thermal spray is investigated. This process allows for high particle velocities and comparatively low process temperatures, resulting in dense coatings with a low oxidation. The microstructure and phase composition of the atomised powder and the HVOF coating were investigated, as well as the wear behaviour under various conditions. A multiphase microstructure was revealed for the powder and coating, whereas a chemically ordered bcc phase occurred as the main phase. The thermal spray process resulted in a slightly changed lattice parameter of the main phase and an additional phase. In comparison with a hard chrome-plated sample, an increase in wear resistance was achieved. Furthermore, no brittle behaviour occurred under abrasive load in the scratch test. The investigation of wear tracks showed only minor cracking and spallation under maximum load.
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Tyurin, Yu N., M. Yu Arseenko, M. S. Prozorova, O. V. Kolisnishenko, and M. G. Kovaleva. "The Wear Resistance of the Nanocomposite Coatings Obtained by the Cumulative- Detonation Device." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35152.
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Nanocomposite coatings based on Ti, O, C and H were deposited on aluminium samples by using the
cumulative-detonation equipment. The nanocomposite coatings were examined by scanning electron microscopy
(SEM), transmission electron microscopy (TEM) with diffraction, X-ray phase analysis, hardness
measurements and tribotests. It was established that the wear of nanocomposite coatings based on Ti, O, C
and H less than to the wear of material of the substrate. For the nanocomposite coating which were formed
from the hydrogenated titanium powder was recorded the lowest wear and coefficient of friction.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35152
21
Tan, Ruoyo. "Protective coatings for Al press tools used in automotive industry." Thesis, Högskolan Väst, Avd för tillverkningsprocesser, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-6858.
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The application of the thermally sprayed WC-Co and Cr 3C2-NiCr coatings have been widely used in industry for its superior sliding, abrasive and erosive wear properties. The Al2O3 coating possessing high hardness can be utilized to improve the wear resistance of the metallic surface. Replacing the stamping tool material from steel to lightweight aluminium with protective coatings offers significant gains such as reduction in power costs and increasing operational efficiency during manufacturing of sheet automobile parts. In this study, the WC-CoCr and Cr3C2-NiCr coatings were sprayed with High Velocity Air-Fuel (HVAF) process and Al2O3 coating was deposited using Atmosphere Plasma Spraying (APS) process. The coatings were evaluated and compared based on the results of roughness tests, hardness tests, adhesion tests, quantitative imaging analysis and microstructure analysis. The experimental results revealed that the roughness value varied in a lower range which implies of a high density of the coatings. It was found that coatings have an extremely high hardness value as tested by the Vickers hardness test. The WC-Co coating was found to be the hardest (1215.2HV). The adhesion test was implemented according to the ASTM C633-79 standard. The result showed that WC-Co and Cr3C2-NiCr coatings without a bond coat had high tensile strength, higher than the respective glue strength (63.54MPa, 75.89MPa). Whereas, the Al2O3 coating has a much lower tensile strength (15.2MPa, 25.68MPa, with and without bond) than others and using a bond coat layer does not contribute to an increase in adhesion strength of the cermet coatings. The coating thickness was evaluated using Light Optical Microscopy (LOM) and microstructure analysis was carried out using Scanning Electron Microscopy (SEM). From the microstructure analysis, it was observed that all the coatings have a dense microstructure, very low porosity and low oxide inclusions in top coat. The WC and Cr3C2 grains retain a large volume fraction of finely dispersed in matrix. The alumina coating was found to have low levels of un-melted or the re-solidified particles in the coating. All of the aforementioned analysis and results reveal that WC/CoCr and Cr3C2-NiCr coating show promising potential for press tool applications. However, abrasive resistance test still remained to be done and will be performed in the future. The result of it can reveal the actual wear resistance between two coatings in reality and will be helpful in determining the better protective coating for aluminium press tools
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Kucita, Pawee. "The development of a wear resistance aluminium bronzes (Cu-Al-Fe) coating." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/403720/.
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Aluminium bronze alloys (Cu-Al-Fe) with Al > 14 wt. % are known to have high wear resistance and low friction coefficient against ferrous metals thus making it an ideal material for forming dies application. However, the use of these alloys has been restricted by the high cooling rate required to prevent embrittlement of the alloy during production. The plasma transferred arc technique (PTA) is an attractive production technique that offers the required high cooling rate, however the resulting microstructure is strongly dependent on the composition change induced during deposition. Therefore to optimise the microstructure for application such as forming dies, thorough understanding of the effects of PTA induced composition change on the microstructure, wear and corrosion resistance properties are required. The composition change induced by PTA involves primarily an increase in Fe. Therefore, in the present research four aluminium bronze coatings with 9, 20, 27 and 35 wt. % Fe were produced from a gas atomized Cu-Al-Fe powder by deposition on to an E.N. 10503 steel substrate by PTA. Microstructure characterisation was carried out using complementary techniques involving SEM, EDS, XRD, EBSD and depth-sensing nano-indentation on etched and electro-polished specimen. The results show that Fe content above 9 wt. % leads to a phase change from the Cu3Al martensitic β1' to solid solution (Cu) phase. This is also accompanied by an increase in size of the Fe3Al intermetallic κ1 phase. The redistribution of Al solute during cooling was identified as the main factor for the observed phase change. These microstructure changes lead to a hardness increase from 4.9 GPa in the coating with 9 wt. % Fe to 5.6 GPa in the coating with 35 wt. % Fe, however hardness mapping using depth-sensing nano-indentation shows that in the high Fe content coating, the hardness distribution is not uniform. This is due to the large volume fraction of the intermetallic κ1 phase which has high hardness of ~7 GPa. The wear resistance of the coating was found to be strongly influenced by the Cu-rich matrix phase. In the coatings with 20, 27 and 35 wt.% Fe, delamination and abrasive wear are the dominant wear mechanisms. SEM observations show that pile-up of slip at the hard intermetallic phase leads to the formation of surface cracks. Coalescence of these cracks coupled with the adhesion between the coating and the ferrous counter material were found to be responsible for promoting delamination wear, which results in high wear rate. The coating with 9 wt.% Fe has the lowest specific wear rates of 2.11-2.87 x 10-4 mm3/Nm against AISI 316, 420 and 440 stainless steel. This is significantly lower than the specific wear rates of 5.95-15.36 x 10-4 mm3/Nm measured for the currently used AISI D2 tool steels at the same condition. This is due to the uniform hardness and retention of the martensitic β1' phase. The effects of PTA induced microstructure change on the corrosion resistance were investigated by electrochemical and immersion corrosion tests in an aerated 3.5 % NaCI solution. The results show that the corrosion resistance of the coating is strongly dependent on complete formation of Al2O3 protective layer. The Al content in the coating is a critical factor in the formation of the protective layer. In the coating with high Fe content where limited Al solutes are available, high corrosion rates of 300-400 x 10-3 mm per year were observed. The 9 wt.% coating which contains the highest Al solute, the lowest corrosion rate of 22.5 x 10-3 mm per year was measured. This corrosion rate is comparable to the more expensive and highly alloyed nickel aluminium bronze. Based on the results obtained in the present research, the coating with a martensitic β1' phase and submicron size intermetallic κ1 phase has the highest wear and corrosion resistance. Such a structure can be achieved by controlling the PTA parameters to minimize the composition change promoted by melting of the steel substrate during deposition. The results from the present research also highlight the importance of interface properties, which have been shown to have a significant influence on properties such as adhesion, wear and corrosion. As more composite materials are utilised, further understanding of the microstructure and properties near the interfaces between materials becomes ever more important. It is hoped that the methodology and results presented in this thesis will provide the initial groundwork for future experimental and modelling work on multiphase material.
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Гладкий, Я. М., С. С. Бись, and О. М. Маковкін. "Трибологія зносостійких покриттів." Thesis, Вид-во СумДУ, 2005. http://essuir.sumdu.edu.ua/handle/123456789/19995.
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Varadarajan, Ashok. "Dross formation mechanism and development of wear resistant scraper in 55Al-1.5Si-Zn coating bath." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=6022.
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Thesis (Ph. D.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains xi, 106 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 101-106).
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Liu, Lian. "Development of novel nanocomposite PVD coatings to improve wear and corrosion resistance of magnesium alloys." Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/18139/.
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The main aim of this research was to develop novel nanocomposite PVD coatings for magnesium alloys, to improve their wear and corrosion resistance – and thereby explore the potential to extend the use of such alloys to moving parts for light-weighting of tribological components, where the potential for cumulative weight savings is immense if key parts can be made from magnesium, but the alloys cannot currently be used successfully due to their poor wear and corrosion behaviour under dynamic loading. The work comprises two main stages. The first stage was to produce a base layer for subsequent PVD ceramic nitride (or nitrogen-doped hard metallic) coating deposition. The second stage was to deposit a nanocomposite coating with improved tribological performance, by introducing sequentially nitrogen reactive gas, subsequent to the base layer preparation step. In the first stage, sixteen AlCuMoMgZrB PVD coating layers were prepared by pulsed direct current closed-field unbalanced magnetron sputtering. Four deposition runs were carried out, with substrate negative bias voltages of 50 V, 60 V, 75 V and 100 V being applied. For each deposition run, four proprietary WE43 magnesium alloy substrates were placed at different positions (P1-P4) on the substrate holder, between AlMgB and ZrMoCu composite sputter targets mounted at 90° to each other. Investigations into composition, microstructure, mechanical and electrochemical properties were then carried out, to select the most suitable base layer. The P1-60 layer (i.e. deposited at P1 position, closest to the AlMgB composite target, with substrate negative bias of 60 V) was chosen as the most suitable candidate amongst the sixteen AlCuMoMgZrB coating layers due to its superior mechanical properties, electrochemical properties, and amorphous microstructure. In the second stage, four novel AlCuMoMgZrB(N) nanocomposite PVD coatings with different nitrogen reactive gas flow rates (i.e. 5 sccm, 10 sccm, 15 sccm and 20 sccm), introduced partway through the sputter deposition process, were produced sequentially, on top of the selected P1-60 base layer. Further detailed investigations into composition, microstructure, mechanical, tribological and electrochemical properties were performed to evaluate the improved wear and corrosion resistance. For practical applications, P1-60-15sccm (46.27 at.% Al, 8.71. at.% Mg, 5.35 at.% Cu, 3.63 at.% Mo, 1.30 at.% Zr, 2.65 at.% B and 32.08 at.% N) seems a likely candidate to provide an optimal combination of wear and corrosion resistance – in terms of the best and the second-best performance in micro-abrasion and in corrosion tests, respectively.
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Prozorova, M. S., O. V. Kolisnishenko, M. G. Kovaleva, M. Yu Arseenko, and Yu N. Tyurin. "Structure and the Physico-Mechanical Properties of the Ceramic Coatings Obtained by the Cumulative -Detonation Device." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35467.
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Dense, with good adhesion to the substrate, hard, wear-resistant coatings from the powder of Al2O3 were
obtained on the surface of the steel (STE255) by using the cumulative-detonation device. The results of investigations
of the structure and physico-mechanical properties of the coatings by using scanning, optical microscopy,
X-ray phase analysis, microhardness and tribological tests are presented. It was found that optimization
of plasma spraying to helps reduce the porosity of coatings of Al2O3 less than 1 % and to increase the hardness
of them to 1250 HV0.3. The tribological investigations have shown that the coatings of Al2O3 significantly increase
the wear resistance of the sample STE255 and provide a low ability to wear out the coating.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35467
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Boban, Greg. "Tribological Comparison of Traditional and Advanced Firearm Coatings." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/361.
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The objective of this project is to find which type of coating has the best performance characteristics for finishing firearms. This is accomplished by measuring and comparing several performance characteristics, such as: adhesion, hardness, wear resistance, friction control, and corrosion resistance. Appearance is not a factor since any exterior coating that is flashy can be subdued or camouflaged with special purpose paints, which have proven durable enough for such purposes. Cost will not be a limiting factor for this experiment, but will be discussed in the conclusion as a secondary concern. This data will be used to identify the best coating for steel and aluminum firearm parts. The goal is to lengthen a firearm’s life cycle while increasing performance and reliability by applying the best coating.
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Бондар, Олександр В`ячеславович, Александр Вячеславович Бондарь, Oleksandr Viacheslavovych Bondar, B. O. Postolnyi, S. S. Grankin, V. M. Beresnev, V. A. Stolbovoy, B. Zhollybekov, and T. N. Koltunowicz. "Structure and Mechanical Properties of Multilayered Nanostructured TiN/ZrN Ion-plasma Coatings." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42763.
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Multilayered coatings based on TiN/ZrN with different thickness of bilayers were deposited on steel substrates using vacuum arc deposition of a cathodes (C-PVD method). Thickness of bilayer strongly depended on deposition conditions and varied in the range 39 – 305 nm, total thickness of the coatings were 11-19 μm. Mechanical and tribotechnical characteristics of the coatings were investigated in the paper as well as its microstructure. Influence of the bilayer thickness on the properties of the coatings were explored.
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Kutschmann, Pia, Thomas Lindner, Kristian Börner, Ulrich Reese, and Thomas Lampke. "Effect of Adjusted Gas Nitriding Parameters on Microstructure and Wear Resistance of HVOF-Sprayed AISI 316L Coatings." MDPI AG, 2019. https://monarch.qucosa.de/id/qucosa%3A34775.
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Gas nitriding is known as a convenient process to improve the wear resistance of steel components. A precipitation-free hardening by low-temperature processes is established to retain the good corrosion resistance of stainless steel. In cases of thermal spray coatings, the interstitial solvation is achieved without an additional surface activation step. The open porosity permits the penetration of the donator media and leads to a structural diffusion. An inhomogeneous diffusion enrichment occurs at the single spray particle edges within the coating’s microstructure. A decreasing diffusion depth is found with increasing surface distance. The present study investigates an adjusted process management for low-temperature gas nitriding of high velocity oxy-fuel-sprayed AISI 316L coatings. To maintain a homogeneous diffusion depth within the coating, a pressure modulation during the process is studied. Additionally, the use of cracked gas as donator is examined. The process management is designed without an additional surface activation step. Regardless of surface distance, microstructural investigations reveal a homogeneous diffusion depth by a reduced processing time. The constant hardening depth allows a reliable prediction of the coatings’ properties. An enhanced hardness and improved wear resistance is found in comparison with the as-sprayed coating condition.
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Lewis, Oliver David. "A study of the influence of nanofiller additives on the performance of waterbourne primer coatings." Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/4646.
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Organic coatings are frequently applied to metals, often in circumstances where there is a need to protect the substrate from corrosion or to improve the aesthetic quality of a product. Increasingly, coatings are also expected to provide additional functionality, such as anti-bacterial properties. Concurrent with the need to satisfy ever more demanding specifications, coating formulators are being obliged to comply with stringent environmental legislation. A research area which may benefit the development of coating formulations is that of nanocomposite synthesis, in which the composite additives have at least one dimension in the nanometre size range. The current research has sought to modify a waterborne organic coating primer with two types of nano-sized additives: layered clays and titanium dioxide nanoparticles. Dispersion of the particles at loadings up to 5% w/w was achieved by ball milling and the modified coatings were subjected to numerous tests to ascertain the effect of the additives. Titanium dioxide was found to improve the tribological properties and corrosion resistance of the coatings, while the addition of magnesium aluminium hydroxycarbonate (hydrotalcite) layered clay had a deleterious effect. Some coatings exhibited a cracked morphology, although no correlation between particle loading and the presence of cracks could be determined. A preliminary investigation into substrate preparation was also conducted. This ensured that the degree of cleanliness of the hot-dip galvanized substrates was both satisfactory and consistent.
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Jedrzejczyk, Pawel. "Analyse et quantification de l'endurance de contact électrique sous sollicitations de fretting." Thesis, Ecully, Ecole centrale de Lyon, 2010. http://www.theses.fr/2010ECDL0016/document.
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La sollicitation de fretting apparait comme un processus de dégradation très pénalisant dans les multiples systèmes industriels (aéronautique, industrie automobile, industriels du nucléaire, transports ferroviaires etc. …). Ce processus d’usure engendre dans la plupart des cas soit une réparation (rechargement) des surfaces soit le remplacement des composants (situation la plus souvent observée). La sollicitation de fretting est associée à des micro-déplacements alternés entre deux surfaces en contact. On observe généralement ce type de sollicitation dans tous les contacts soumis à des vibrations ou à des cycles thermiques. La sollicitation de fretting usure dans les contacts électriques est particulièrement pénalisante. Outre l’endommagement des surfaces, ce processus induit une augmentation significative de la résistance électrique des contacts et une perte de fonctionnalité du connecteur en particulier dans les connecteurs basses tensions très sensibles aux fluctuations de la résistance électrique. Pour palier ce problème les industriels de la connectique et leurs clients (industriels de l’automobile) cherchent à mettre en place de nouveaux dépôts palliatifs pour résoudre ces problèmes tout en limitant les surcouts liés à l’utilisation de dépôts nobles tels que l’or.Le sujet de cette thèse porte sur cette problématique avec pour objectif de mettre en place une méthodologie de choix des dépôts pour optimiser la durée de vie des connecteurs. L’étude aborde essentiellement l’influence des conditions de chargements mécaniques et plus particulièrement l’amplitude de débattementThe degradation by fretting appears as a very troublesome process in many industrial systems (spatial, automotive, nuclear industry, railway systems etc. …). This wear process makes it necessary to repair or to replace the destroyed component. The process of degradation by fretting is associated with the micro-displacement between two surfaces in contact. This type of degradation is observed in all types of contacts subjected to the vibrations or thermal variations. The degradation by fretting in electrical contact is particularly dangerous. The wear of the contacting surfaces causes a significant increase of the electrical resistance of the contact and the decay of the functional properties of the connector. This situation concerns especially the low tension connectors very sensible to the fluctuations of the electrical resistance. In order to avoid this situation the automotive industry and its suppliers, the manufacturers of the electrical connectors, are looking for new materials and coatings.The objective of this thesis consists to develop the methodology of choice of the coating materials in order to optimise the lifetime of the electrical contact. The study focuses mainly on the influence of the mechanical conditions, the displacement amplitude in particular, on the performance of the electrical connector
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Говорун, Тетяна Павлівна, Татьяна Павловна Говорун, Tetiana Pavlivna Hovorun, Олександр Валерійович Пилипенко, Александр Валериевич Пилипенко, Oleksandr Valeriiovych Pylypenko, Костянтин Олександрович Дядюра, et al. "Зносостійкі покриття на основі Ti, Al та N для виробів машинобудування і різального інструменту." Thesis, Сумський державний університет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/47293.
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Плівкові покриття на основі нітриду титана (TiN) отримали широке застосування як захисні покриття в машинобудуванні, інструментальному виробництві, в мікроелектроніці і т.п. Висока твердість дає можливість широко використовувати їх як захисно-декоративні покриття в стоматології, зміцнюючі та зносостійкі покриття для різальних інструментів. Відновлення інструментів та надання необхідної твердості деталям машин, що працюють в умовах високих навантажень, є важливою практичною задачею у зв’язку з їх постійним зношенням. У мікроелектроніці, високі теплова та хімічна стійкість, висока температура плавлення і низький об'ємний коефіцієнт питомого електричного опору TiN, дають можливість застосовувати його як адгезійний шар і дифузійний бар'єр для різних типів з’єднань в багатошарових структурах [1].
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Bryngelsson, Maria. "Relations between the performance of a coated cutting tool and the composition and properties of the wear resistant coating : A study including first principles modeling, mechanical properties and technological testing." Thesis, Uppsala universitet, Materialteori, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-207566.
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This thesis work was performed at AB Sandvik Coromant and aimed to enhance the knowledge about the relationships between the performance of TiN and TiAlN-coated cutting tools in metal turning and their mechanical and chemical properties. Measurements of coating material properties and turning wear tests in annealed tool steel Sverker 21, stainless steel 316L, grey cast iron V314 and nodular cast iron SS0727 were performed. The cutting temperatures were estimated from FEM-simulations. To find the dominant wear mechanism and identify the properties that are most important for the resistance against that particular wear, a correlation analysis was performed together with a wear study using LOM, SEM and EDS. The results show that relations between cutting performance and mechanical properties and/or composition of the coatings can be established. The FEM-simulations suggested that the peak tool temperature was highest, ~750°C, for turning in 316L and lowest for turning in Sverker 21, ~300°C. Turning in cast iron resulted in temperatures around 500-550°C. A mechanism for the growth of the crater on inserts tested in stainless steel 316L is proposed. Wear due to thermo-mechanical load and adhesion are believed to be the dominating wear mechanisms. The performance of the tool showed a high correlation to the composition of the coatings, with a decreased tool life for higher Al-contents. The reason for this might lie in an increased brittleness of these coatings, accelerating formation of lateral cracks above the crater. Calculated ratios of bulk and shear modulus suggests an increased brittleness for higher Al-contents. A higher tendency to stick to the work piece material might also contribute to a decrease in tool life. An Increased Al-content could also drive the formation of c-AlN to h-AlN, causing even higher wear rates. The coatings with higher substrate bias showed an enhanced performance, even though the crack pattern was worsened for these variants. The reason for the enhanced performance seen for these variants might instead originate in an enhanced adhesion to the substrate. In the flank wear resistance test in Sverker 21 the Al-content proved to be important, with an improved performance for higher Al-contents. In contrast to the test in 316L, a change in bias or hardness had no effect on the performance in this test. Scratch patterns on the flank supports that an abrasive wear mechanism is present, but no correlation between hardness and tool life could be obtained. Either some other material property than hardness is of importance for the abrasive resistance in this test, or another wear mechanism, occurring simultaneously with abrasion, is the wear rate deciding. The second part of this thesis work was to evaluate the ability of a quantum mechanical computational method, density functional theory, to predict material properties. The method predicts the lattice parameters and bulk moduli in excellent agreement with experimental values. The method also well predicts other elastic properties, with results consistent with reference values. There seems to be a constant shift of about 50-100 GPa between the calculated elastic modulus and the experimentally measured values, probably originating in contributions from grain boundaries, texture, stresses and defects present in the real coatings, and possibly also in errors in the experimental method due to an influence from the substrate. The calculated hardness values did not follow the trend of an increased hardness for TiAlN compared to TiN, which is seen in experiments.
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Гончаров, Олександр Андрійович, Александр Андреевич Гончаров, Oleksandr Andriiovych Honcharov, Р. Ю. Бондаренко, Л. В. Васильєва, and О. В. Агулов. "Моделювання теплових процесів при різанні." Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/41155.
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Відомо, що нанесення зносостійких покриттів на основі нітридів та карбідів тугоплавких з‘єднань, широко використовується для зменшення зносу ріжучого інструменту [1]. Використання захисних покриттів на швидкоріжучих сталях зменшує величину зносу, за рахунок сповільнення рекристалізаційних процесів в матеріалі інструмента, а також за рахунок зменшення потужності теплового потоку, діючого на
ріжучий інструмент.
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Харченко, Надія Анатоліївна, Надежда Анатольевна Харченко, Nadiia Anatoliivna Kharchenko, Віктор Гаврилович Хижняк, Виктор Гаврилович Хижняк, Viktor Havrylovych Khyzhniak, Олександр Олегович Голишевський, Александр Олегович Голишевський, and Oleksandr Olegovich Holyshevskyi. "Зносостійкість сталі У8А після азотохромування." Thesis, Запорізький національний технічний університет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/37766.
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Досліджено будову, механічні властивості захисних покриттів за участю вуглецю, азоту та хрому на сталі У8А. Наведено порівняльні експериментальні дані по зносостійкості вихідної сталі У8А і стали зі зносостійкими покриттями в умовах тертя-ковзання без змащування з попередньою і без попередньої притирки поверхонь. Встановлено формування трьох зон, що відрізняються за хімічним складом. Комплексна обробка сталі У8А призводить до підвищення її зносостійкості в 1,2 рази порівняно з хромуванням, в 2,7 рази з азотування і в 3,5 рази зі сталлю У8А без обробки.Исследованы строение, механические свойства защитных покрытий с участием углерода, азота и хрома на стали У8А. Приведены сравнительные экспериментальные данные по износостойкости исходной стали У8А и стали с износостойкими покрытиями в условиях трения-скольжения без смазки с предварительной и без предварительной притирки поверхностей. Установлено формирование трех зон, отличающихся по химическому составу. Комплексная обработка стали У8А приводит к повышению ее износостойкости в 1,2 раза по сравнению с хромированием, в 2,7 раза с азотированием и в 3,5 раза со сталью У8А без обработки.
Studied the structure and mechanical properties of protective coatings involving carbon, nitrogen and chromium on steel WA. Comparative experimental data on the durability of the original steel У8А and steel with wear-resistant coatings in conditions of friction-slip without lubrication and without prior pre-lapping surfaces. The formation of three zones differing in chemical composition. A comprehensive treatment of steel У8А increases its wear resistance by a factor of 1,2 compared to chromium, 2,7 times with nitriding and 3,5 times with steel У8A without treatment.
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Antônio, César Augusto [UNESP]. "Deposição de filmes por plasma eletrolítico em ligas de alumínio." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/88448.
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antonio_ca_me_bauru.pdf: 1720399 bytes, checksum: 396bef6efc3f71eb7d1f9f3cad7c2279 (MD5)Apesar da excelente relação resitência/peso das ligas de alumínio, a aplicação tecnológica destas ligas é limitada pela baixa resistência ao desgaste. Neste trabalho, amostras de uma liga de alumínio (AA 5052) foram tratadas pelo processo de oxidação por plasma eletrolítico, com tempo de exposição variando de 150 a 900 s. A composição e a estrutura química dos revestimentos assim produzidos foram analisadas por espectroscopia de absorção no infravermelho. Um método baseado na medida de correntes parasitas e a perfilometria foram usados, respectivamente, na determinação da espessura e da rugosidade das camadas depositadas. O revestimento formado porssui espessura de até 9,2um. Análises da morfologia dos revestimentos foram feitas com microscopia eletrônica de varredura enquanto a resistência a desgastte das superfícies foi avaliada com um sistema pino-sobre-disco. Os resultados revelaram a deposição de um revestimento cerâmico, que conferiu expressivo aumento à resistência a desgaste da liga, o qual mostrou que as amostras tratadas suportaram uma carga aplicada de 13,44 vezes em comparação com amostras sem tratamento
Despiste the excellent strengh/weight ratio, technological applications of aluminum aloys are limited by their low wear resistance. In this work, samples of AA 5052 aluminum alloy have been modified by plasma electrolytic oxidation, with exposure time ranging from 150 s to 900 soconds. Compositional characterization has been performed by fourier transform infrared spectroscopy. Eddy current and profilometry have been used, respectively, to evaluate thickness and roughness of the deposited layers. The coating formed has a thickness of up to 9,2 micrometers. Morphological investigations have been performed with scanning electron microscopy while wear resitance has been assessed using a pin-on-disk devide. The results have revealed the deposition of ceramic layers with significant enhancement of wear resistance, which showed that the treated samples resistance, which showed that the treated samples resist an applied load 13.44 times more compared with untreated samples
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Paul, Arindam. "Development and evaluation of NiW alloy and NiW-TiO2 composite coatings on the mechanical properties, tribological performance and the corrosion resistance of bearing steel." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1618853855083468.
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Гуменюк, Ігор Анатолійович. "Триботехнічні властивості сталі 12Х18Н10Т, поверхнево модифікованої комбінованими покриттями." Thesis, Національний авіаційний університет, 2018. http://er.nau.edu.ua/handle/NAU/36124.
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Гуменюк І.А. Триботехнічні властивості сталі 12Х18Н10Т, поверхнево модифікованої комбінованими покриттями. – На правах рукопису.
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю: 05.02.04 – тертя та зношування в машинах (13 – Механічна інженерія). Національний авіаційний університет, МОН України, Київ, 2018.
Дисертаційна робота присвячена вирішенню актуального науково-технічного завдання підвищення зносостійкості поверхневих шарів корозійностійкої сталі 12Х18Н10Т шляхом формування зносостійких комбінованих дифузійних, електроіскрових та композиційних електролітичних покриттів дискретного і градієнтного типу та встановлення закономірностей впливу їх структурно-фазового складу, фізико-механічних властивостей і параметрів структури на триботехнічні характеристики.
Дослідженні закономірності формування та механізми зношування багатокомпонентного хромоалітованого покриття в умовах тертя ковзання без змащення в залежності від хімічного і структурно-фазового складу.
Представлено та описано результати експериментальних досліджень технологічного процесу азотування попередньо обробленої дискретно лазером сталі 12Х18Н10Т. Встановлено закономірності зношування від параметрів дискретної структури.
Досліджено закономірності формування високотемпературним відпалом триботехнічних властивостей електроіскрових і композиційних електролітичних покриттів з евтектичним наповнювачем від ступеня нерівноважності структурно-фазових станів.
Теоретично обґрунтовано та експериментально підтверджено вплив дифузійної перехідної зони між твердим наповнювачем і м’якою матрицею на напружено-деформований стан та зносостійкість композиційних електролітичних покриттів.
На основі енергетичної моделі трибопроцесу виконано аналітичне дослідження умов утворення частинок зносу в процесі фрикційного руйнування приповерхневих шарів композиційного покриття.
Застосовуючи енергетичний підхід до оцінювання зносостійкості поверхневих шарів за умов їх руйнування при терті розроблено технологічний процес формування на сталі 12Х18Н10Т градієнтного покриття з високою припрацьовуваністю і зносостійкістю. Проведено статистичний аналіз та побудовано регресійні моделі залежностей критеріїв оптимізації.Gumenyuk I.A. Tribotechnical properties of steel 12C-18Cr-10Ni-Тi, surface-modified by combined coatings. – Manuscript. Thesis intended for getting scientific degree of Candidate of technical science by specialty: 05.02.04 – Friction and wear in machines (131 – Mechanical Engineering). National Aviation University, Ministry of Education and Science of Ukraine, Kyiv, 2018. The thesis is devoted to solving the actual scientific and technical task of increasing the wear resistance of surface layers of corrosion–resistant steel 12C-18Cr-10Ni-Тi by forming wear resistant combined diffusion, electrospray and composite electrolytic coatings of discrete and gradient type and establishing regularities of influence of their structural-phase composition, physical and mechanical properties and structural parameters on tribotechnical behavior. Investigation of regularities of formation and mechanisms of wear of multi-component chromoalluminized coating in conditions of dry sliding friction, depending on the chemical and structural-phase composition have been done. The results of experimental examinations of technological process of nitriding of selectively laser pre-treated steel 12C-18Cr-10Ni-Тi are presented and described. The regularities of wear on parameters of a discrete structure have been established. The regularities of formation of tribotechnical properties of electrospray and composite electrolytic coatings with eutectic filler by high-temperature annealing on the degree of nonequilibrim of structural-phase states were studied. The influence of the diffusion transition zone between the solid filler and the soft matrix on the stress-strain state and the wear resistance of composite electrolytic coatings was theoretically proved and experimentally confirmed. Based on the energy model of triboprocess, an analytical study of conditions for the formation of wear particles in the process of frictional destruction of near-surface layers of composite coating was carried out. Using the energy approach to evaluation of wear-resistance of surface layers in conditions of their fracture at friction, a technological process of forming gradient coating on the surface of 12C-18Cr-10Ni-Тi steel with high workability and wear resistance was developed. A statistical analysis was carried out. Regression models of dependencies of optimization criteria were constructed.
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Silva, Fernando Santos da [UNESP]. "Avaliação das propriedades mecânicas e de resistência à corrosão de revestimentos à base de alumínio, carbetos de tungstênio e cobre obtidos por aspersão fria." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/151738.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Este trabalho teve como objetivo investigar a microestrutura, resistência à corrosão e propriedades mecânicas de revestimentos produzidos por Aspersão Fria (AF) a base de: (I) pó de alumínio (Al), com ou sem alumina (Al2O3), depositados sobre aço comum; (II) revestimentos metálico-cerâmicos de WC-12Co e WC-25Co depositados sobre a liga Al7075-T6 e (III) revestimentos de cobre depositados sobre aço e obtidos a partir de pós submetidos a diferentes tratamentos. A análise dos materiais de partida e dos revestimentos, antes e após os ensaios de corrosão, foi realizada por difração a laser (DL), microscopia óptica (OM), microscopia eletrônica de varredura (SEM) acoplado a um sistema de espectroscopia de dispersão de energia de raios X (EDS) e difração de raios X (DRX). Foram realizadas medidas de dureza e ensaios de resistência ao desgaste por abrasão (Rubber Wheel) e por deslizamento (Ball on disk). A resistência à corrosão dos revestimentos foi avaliada por medidas eletroquímicas em meio de NaCl 3,5% e testes de névoa salina. Foram realizadas medidas de potencial em circuito aberto (ECA), espectroscopia de impedância eletroquímica (EIS) e curvas de polarização linear e cíclica. As imagens de SEM da secção transversal mostram que os revestimentos são densos, não possuem porosidade interconectada e nem trincas. Os resultados eletroquímicos e de névoa salina mostram que todos os revestimentos investigados protegem o substrato por longos tempos de imersão por serem compactos quando obtidos pela tecnologia de AF. Para os revestimentos a base de alumínio, os estudos mostram que o eletrólito atinge o substrato em alguns pontos somente após 2000 h de imersão e os ensaios de desgaste indicam que o revestimento compósito Al-Al2O3 apresenta melhores propriedades mecânicas. Quanto aos revestimentos metálicocerâmicos, o revestimento de WC-25Co apresentou maior espessura e também maior proteção contra corrosão até tempos maiores do que 2000 h. A caracterização dos revestimentos de cobre mostra claramente que os diferentes tratamentos dos materiais de partida exercem influência na eficiência de deposição, formação dos revestimentos e principalmente na sua resistência à corrosão.
The purpose of this work was to investigate the microstructure, corrosion resistance and mechanical properties of coatings prepared by Cold Gas Spray (CGS) based on: (I) aluminum (Al) powder with or without alumina (Al2O3), deposited on common steel; (II) WC-12Co and WC-25Co metallic-ceramic coatings deposited onto Al7075- T6 alloy and (III) copper coatings deposited onto common steel and obtained from powders submitted to different treatments. The analysis of the feedstock materials and the coatings before and after the corrosion tests were performed by laser diffraction (LD), optical microscopy (OM), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy system (EDS) and X-ray diffraction (XRD). Hardness measurements, abrasion testing (Rubber Wheel) and sliding wear test (Ball on disk) were performed. The corrosion resistance of the coatings was evaluated by electrochemical measurements in 3.5% NaCl medium, and salt fog tests. Open circuit potential (EOC), electrochemical impedance spectroscopy (EIS), linear and cyclic polarization measurements were performed. SEM images of the cross section showed that coatings are dense, without interconnected porosity and cracks. Electrochemical and salt fog results show that all investigated coatings protect the substrate during long immersion times because they are compact when obtained by CGS technology. For the aluminum based coatings, the studies show that the electrolyte reaches the substrate at some points only after 2000 h of immersion and the wear tests show that the Al-Al2O3 composite coating has better mechanical properties. For the metal-ceramic coatings, the WC-25Co coating show higher thickness and corrosion protection up to 2000 h of immersion when compared to WC-12Co. Copper coatings characterization clearly shows that the different treatments of the feedstock materials exert influence on the deposition efficiency, coating formation and especially on their corrosion resistance.
CNPq: 153177/2014-4
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Grandin, Martina. "Tribology of Metal-Graphite Composites : A Study of Sliding Electrical Contact Surfaces." Doctoral thesis, Uppsala universitet, Tillämpad materialvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-329860.
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An environmentally sustainable production of electrical power is important for preserving the earth’s natural resources. In order to utilize this power as efficiently as possible, it is of great importance to minimize the losses, for example in sliding electrical contacts. A sliding electrical contact is where current is transferred from one rotating to one stationary component and power is lost due to friction and contact resistance. Also in some signal applications, high performance sliding contacts are crucial to ensure stable signal transfer with low noise. Although sliding electrical contacts are primarily designed for good electrical performance, the system will benefit also from optimization of the tribological properties. The aim of this thesis is to increase the fundamental knowledge of the tribological and electrical performance of metal-graphite composite materials for sliding electrical contacts. The influence of mechanical and electrical load was investigated. Different stationary materials, from pure copper to nanocomposite coatings, were tested against copper- and silver-graphites. Two complementary test setups were used, one with reciprocating and one with unidirectional sliding. Surface analysis was essential to gain deepened understanding of the influence of the interaction on the surfaces. Especially my novel imaging of cross-sections has advanced the level on knowledge in this research field. On the stationary material surface, a tribofilm forms with constituents from the metal-graphite and the surrounding atmosphere. Cross-sectioning reveals a material flow that indicates turbulence. Furthermore, the presence of oxides in the tribofilm is not necessarily detrimental for the contact resistance as long as there is also pure metal available. The presence of graphite is vital for low friction and wear. It is shown that the tribological and electrical behaviour of this system is only marginally influenced by the material selection of the stationary contact. Increasing the metal content in the composite, on the other hand, greatly reduces the contact resistance while there is no significant impact on friction and wear. The mechanical load has to be optimized to compromise between low wear (achieved with low load) and low contact resistance (achieved with high load). Pure mechanical tests show a lower friction and higher wear rate in comparison to tests with a five ampere current.
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Krčál, Petr. "Frézování vnitřních závitů na tělesech vstřikovacích jednotek Bosch." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229162.
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At the beginning of this diploma thesis I describe the production of different types of threads (with special emphasis on the production of internal threads), then I discuss different types of application of abrasion resistant coating by PVD and CVD, I describe their main advantages and disadvantages. Further, this diploma thesis explains particular mechanisms and forms of tool wear on tool with coating. In the second part of this diploma thesis the analysis of the current status of the production of internal threads in the Rail (high-pressure chamber) is made. In the last part I compare six different threads cutters by the use of a scanning electron microscope
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Lagrange, Laurent. "Caractérisation microstructurale et tribologique de revêtements composites à matrice métallique élaborés sous faisceau laser par projection coaxiale de poudre." Vandoeuvre-les-Nancy, INPL, 1997. http://docnum.univ-lorraine.fr/public/INPL_T_1997_LAGRANGE_L.pdf.
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Nous présentons une étude sur l'élaboration et sur la résistance a l'usure de revêtements composites à matrice métallique (base Ni). On réalise des couches épaisses de rechargement à l'aide d'un jet de poudre de particules de WC de granulométrie contrôlée, formé par une buse originale, coaxiale au faisceau laser assurant la fusion du liant et superficielle du substrat métallique. Les surfaces ainsi rechargées sont rectifiées avant utilisation. On étudie d'abord le jet de gaz de transport avec et sans poudre afin d'optimiser le procédé, notamment en matière de rendement de poudre déposée. Une analyse, en fonction des paramètres du traitement, des épaisseurs du cordon de rechargement, du substrat refondu et de sa zone affectée thermiquement, aboutit à la réalisation de revêtements à faible taux de dilution. On montre qu'on minimise ainsi la dissolution des carbures dans la matrice et réduit au maximum le danger de modification des propriétés mécaniques des matériaux de départ. La dureté de ces revêtements composites est établie par rayure. Cette dureté sclérométrique, Hs, augmente nettement, à granulométrie constante, avec le taux du renfort. À taux de renfort constant l'incidence de la granulométrie est apparemment faible et conduit à des hétérogénéités locales importantes. Dans une seconde partie, on caractérise, en fonction de la taille (50micromètres - 210micromètres) et de la fraction massique (0% - 65%) des carbures, le comportement tribologique des revêtements en érosion sous l'effet d'un jet de grenaille et en usure de type pion/disque : - en érosion on optimise la résistance à l'usure en augmentant la fraction massique des carbures et/ou en diminuant la granulométrie. Ces variations découlent respectivement d'augmentation de Hs et de la ténacité globale du composite. - En configuration pion/disque et à faible température de contact, la résistance à l'usure suit une loi d'Archard et augmente avec Hs (donc également avec la fraction massique en renfort). Par contre, l'augmentation de la taille des carbures a ici un effet bénéfique, attribué à l'affaiblissement relatif de la composante d'usure abrasive imputable à la présence de débris dans le contact. À température de contact élevée, le meilleur comportement des composites à liant d'Inconel, est attribué à la meilleure dureté à chaud de ce superalliage.
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Кульпина, К. А., and K. A. Kulpina. "Исследование износа и стойкости токарных резцов с алмазоподобным покрытием : магистерская диссертация." Master's thesis, б. и, 2021. http://hdl.handle.net/10995/100784.
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Магистерская диссертация выполнена на тему: «Исследование износа и стойкости токарных резцов с алмазоподобным покрытием». Расчётно-пояснительная записка содержит 94 листа, 86 рисунков, 6 таблиц, 23 источника, 1 приложение. Объектом исследования данной работы являются токарные резцы с алмазоподобным покрытием. Цель работы – определить наиболее благоприятные условия работы токарных резцов с алмазоподобным покрытием. В результате выполнения работы были проведены исследования износа алмазоподобного покрытия на токарных резцах, построены и проанализированы графики зависимостей этих износов. Проведен анализ полученных результатов и выдвинута гипотеза об еще одной возможной причине разрушения покрытия, в то время как остальные известные причины устранены. Разработаны конструкции токарных резцов и проведено исследование предлагаемой гипотезы. По результатам исследования проведен расчет прочности и подтверждена предлагаемая гипотеза.The master's dissertation is carried out on the topic: "Investigation of wear and resistance of cutting tools with a diamond-like coating". The settlement and explanatory note contains 94 sheets, 86 figures, 6 tables, 23 sources, 1 attachment. The object of research in this work is diamond-coated lathe tools. The purpose of the work is to determine the most favorable working conditions for lathe tools with a diamond-like coating. In the course of the work, the study of the wear of the diamond-like coating on lathe tools at various cutting modes was carried out, the graphs of the dependences of these wear in time were built and analyzed. The analysis of the results obtained is carried out and a hypothesis is put forward about another possible cause of the destruction of the coating, while the other known causes have been eliminated. To confirm the hypothesis, the designs of lathe tools were developed and a study was carried out. According to the results of the study, the strength calculation was carried out, the proposed hypothesis was confirmed.
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Pongrácz, Jakub. "Vliv modifikace HVOF nástřiku slitiny NiCrBSi elektronovým paprskem na jeho strukturu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400445.
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This thesis deals with surface re-melting by electron beam of thermal sprayed material NiCrBSi by method HVOF. The microstructure, chemical and phase composition, hardness and abrasive wear resistance were evaluated in depending on the electron beam parameters and modes of the electron beam 6-poinst and line. Observed microstructure was better after both methods of re-melting. The splats were not observed, coating porosity decreased and structure was more homogenous. Structure and phase analysis was acquired by light microscopy, scanning electron microscopy, energy dispersive spectroscopy and x-ray diffraction. A small change in hardness between modes of re-melting was observed, but measured hardness was higher than in sample without re-melting. Similar results were observed for abrasion resistance.
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Сарварова, Я. Э., and Y. E. Sarvarova. "Исследование износа и стойкости концевых фрез с алмазоподобным покрытием : магистерская диссертация." Master's thesis, б. и, 2021. http://hdl.handle.net/10995/100785.
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Объектом исследования данной работы являются концевые фрезы с алмазоподобным покрытием. Цель работы – определить наиболее благоприятные условия работы концевых фрез с алмазоподобным покрытием. В результате выполнения работы были проведены исследования износа алмазоподобного покрытия на концевых фрезах, построены и проанализированы графики зависимостей этих износов. Проведен анализ полученных результатов и выдвинута гипотеза об еще одной возможной причине разрушения покрытия, в то время как остальные известные причины устранены. Проведено исследование предлагаемой гипотезы. По результатам исследования проведен расчет прочности и подтверждена предлагаемая гипотеза.The object of research in this work is diamond-coated end-milling cutters. The purpose of the work is to determine the most favorable working conditions for end-milling cutters with a diamond-like coating. In the course of the work, the study of the wear of the diamond-like coating on end-milling cutters at various cutting modes was carried out, the graphs of the dependences of these wear in time were built and analyzed. The analysis of the results obtained is carried out and a hypothesis is put forward about another possible cause of the destruction of the coating, while the other known causes have been eliminated. To confirm the hypothesis a study was carried out. According to the results of the study, the strength calculation was carried out, the proposed hypothesis was confirmed.
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Mao, Fang. "Synthesis, Characterization, and Evaluation of Ag-based Electrical Contact Materials." Doctoral thesis, Uppsala universitet, Oorganisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-320235.
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Ag is a widely used electrical contact material due to its excellent electrical properties. The problems with Ag are that it is soft and has poor tribological properties (high friction and wear in Ag/Ag sliding contacts). For smart grid applications, friction and wear became increasingly important issues to be improved, due to much higher sliding frequency in the harsh operation environment. The aim of this thesis is to explore several different concepts to improve the properties of Ag electrical contacts for smart grid applications. Bulk Ag-X (X=Al, Sn In) alloys were synthesized by melting of metals. An important result was that the presence of a hcp phase in the alloys significantly reduced friction coefficients and wear rates compared to Ag. This was explained by a sliding-induced reorientation of easy-shearing planes in the hexagonal structure. The Ag-In system showed the best combination of properties for potential use in future contact applications. This thesis has also demonstrated the strength of a combinatorial approach as a high-throughput method to rapidly screen Ag-based alloy coatings. It was also used for a rapid identification of optimal deposition parameters for reactive sputtering of a complex AgFeO2 oxide with narrow synthesis window. A new and rapid process was developed to grow low frictional AgI coatings and a novel designed microstructure of nanoporous Ag filled with AgI (n-porous Ag/AgI) using a solution chemical method was also explored. The AgI coatings exhibited low friction coefficient and acceptable contact resistance. However, under very harsh conditions, their lifetime is too short. The initial tribotests showed high friction coefficient of the n-porous Ag/AgI coating, indicating an issue regarding its mechanical integrity. The use of graphene as a solid lubricant in sliding electrical contacts was investigated as well. The results show that graphene is an excellent solid lubricant in Ag-based contacts. Furthermore, the lubricating effect was found to be dependent on chemical composition of the counter surface. As an alternative lubricant, graphene oxide is cheaper and easier to produce. Preliminary tests with graphene oxide showed a similar frictional behavior as graphene suggesting a potential use of this material as lubricant in Ag contacts.
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Perrinet, Olivier. "Analyse de l'endurance de contacts électriques Sn, Au et Ag soumis à des sollicitations complexes de fretting usure." Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0009.
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Dans les applications automobiles et dans d'autres domaines (énergie, aviation, etc), le nombre d'appareils électroniques a augmenté de façon significative au cours des dernières décennies. La sécurité des systèmes et des personnes repose sur la qualité de connecteurs électriques. Toutefois, soumis à des vibrations (moteur de la voiture, de l'environnement) des microdéplacements sont induits à l’interface. La problématique du contact électrique est principalement liée à l'altération de la conduction de faible courant (5mA) dans les interfaces soumises à des contraintes mécaniques de glissement répétitifs engendrant un phénomène bien connu de fretting par l’usure. La sollicitation de fretting usure apparait comme un processus de dégradation très pénalisant. Outre la détérioration des surfaces, ce processus conduit à une augmentation de la résistance électrique des contacts et à une possible perte du signal électrique. Ceci est particulièrement le cas pour les connecteurs bas niveau très sensibles aux fluctuations de la résistance électrique. Pour remédier à cela, les acteurs de la connectique développent de nouveaux dépôts pour limiter l’utilisation de dépôts nobles tels que l’or. Les objectifs de cette thèse sont d’établir une "table d’utilisation" des revêtements en fonction de sollicitations précises et de mettre en place une méthodologie dans le choix des dépôts en vue d’optimiser la durée de vie des connecteurs. L’étude aborde différents aspects tels que les influences des conditions de chargements mécaniques, des épaisseurs de dépôts, du type de dépôt (noble, non noble, dopé), de l’amplitude de débattement (micro-déplacement et grand déplacement) et la formalisation de l’endurance électrique (loi puissance et approche énergétique)In automotive applications and in other areas (energy, aviation, etc.), the number of electronic devices has increased significantly in recent last decades. Systems and people securities are based on the quality of electrical connectors. However, submitted to vibrations (car engine, environment) micro-displacements are induced at the interface. The problem of electrical contact is mainly due to the impairment of low current conduction (5mA) in interfaces subjected to repetitive sliding displacement generating a well-known fretting wear phenomenon. Fretting wear solicitation appears as a process of very detrimental degradation. Besides surface deterioration, this process leads an increase of the electrical contact resistance and a possible loss of the electrical signal. This is particularly the case of the low level connectors which are very sensitive to electrical contact fluctuations. To remedy, connections actors develop new deposits to limit the use of noble ones such as gold. The objectives of this thesis are to establish a "table of use" coatings based on specific solicitations and define a methodology for the selection of deposits to optimize the lifetime connectors. The study covers different aspects such as the mechanical loading conditions influence, the thickness deposits influence, the type of deposit (noble, non-noble, doped), the displacement amplitude (microdisplacement and large displacement) and the electrical endurance formalization (energetic approach and power law)
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Dingremont, Norbert. "Analyse de la compatibilité des traitements de nitruration par voie ionique avec les dépôts par plaquage ionique : application à l'acier de construction 35NCD16 et à l'acier d'outillage pour travail à chaud Z38CDV5." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL110N.
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Afin de déterminer dans quelle mesure les traitements de nitruration par voie ionique peuvent être compatibles aves les dépôts par plaquage ionique, nous avons analysé l'influence de la procédure de dépôt sur la stabilité des couches nitrurées. Ce travail a permis de montrer que le cycle thermique associé à la procédure de dépôt peut conduire à lui seul à la déstabilisation des couches de combinaison et seulement celles-ci. Dans ce cas, la stabilité thermique intrinsèque des couches de combinaison est mise en cause. Nous avons également mis en évidence la déstabilisation de ces mêmes couches lors de la réalisation de l'étape de décapage ionique effectuée sous plasma d'argon seul et ce, pour des températures de dépôt relativement basse (400°C). Ce phénomène conduit à la dénitruration des couches de combinaison et à la formation d'une interphase ferritique qui est à l'origine des problèmes d'adhérence observés lors de l'élaboration de revêtements durs. L’introduction d'une pression partielle d'azote contrôlée dans le plasma d'argon au début de l'étape de décapage permet de contourner ce problème, elle met également en évidence la présence d'espèces nitrurantes dans le plasma. Cette constatation nous a permis d'envisager l'étude de la faisabilité des traitements de nitruration dans les installations de dépôt BALZERS. Celle-ci a conduit à la réalisation des traitements plurifonctionnels de nitruration et de dépôt dans une même installation d'une part, en raison des gains cinétiques observés au niveau du traitement thermochimique et d'autre part, en raison d'une meilleure adhérence du dépôt sur les couches nitrurées. En effet, la transition entre les deux traitements ne nécessite pas une remise à l'air de l'installation ce qui réduit considérablement les risques de contamination interfaciale couche nitrurée - revêtement. En second lieu, l'élévation des vitesses de nitruration, provenant d'une plus grande réactivité des faisceaux de plasma à haute densité de courant, a permis d'industrialiser de façon rentable ce nouveau procède de traitement plurifonctionnel
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Артемчук, Віктор Васильович, Виктор Васильевич Артемчук, and Viktor V. Artemchuk. "Наукове обґрунтування відновлення деталей шаруватими покриттями при ремонті рухомого складу залізниць." Thesis, Видавництво Дніпропетровського національного університету залізничного транспорту імені академіка В. Лазаряна, 2012. http://eadnurt.diit.edu.ua:82/jspui/handle/123456789/1323.
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Артемчук, В. В. Наукове обгрунтування відновлення деталей шаруватими покриттями при ремонті рухомого складу залізниць : авт. дис. д-ра т. н.: 05.22.20 / В. В. Артемчук ; Дніпропетр. нац. ун-т залізн. трансп. ім. акад. В. Лазаряна. - Д. : Вид-во Днiпропетр. нац. ун-ту залізн. трансп. iм. акад. В. Лазаряна, 2012. УДК 629.4.027:621.79 ГРНТИ 55.41.29UK:АНОТАЦІЯ Дисертаційна робота присвячена вирішенню наукової проблеми підвищення ресурсу та надійності експлуатації залізничного рухомого складу при ремонті. По-ставлена та розв’язана задача зі встановлення зв’язків між параметрами технологі-чних процесів відновлення деталей рухомого складу залізниці, структурою та вла-стивостями шаруватих покриттів. Розроблена та представлена в дисертаційній роботі математична модель із визначення раціональних параметрів відновлювального шаруватого покриття деталей рухомого складу при ремонті, яка дозволяє підприємству встановлюва-ти раціональні режими та технологію відновлення зношених деталей з враху-ванням вартісних показників процесу. Використовуючи інструменти векторної оптимізації, запропонований алгоритм оцінки якості відновлення деталей рухомого складу за декількома показниками. Роз-роблено рекомендації відносно вибору режимів, технології і техніки відновлен-ня зношених деталей рухомого складу шаруватими покриттями, що забезпечу-ють високу якість і надійність експлуатації обраних деталей. Запропонована методика оцінки надійності роботи деталей, відновлених шару-ватими покриттями, яка дозволяє визначати імовірність безвідмовної роботи цих деталі з врахуванням зносу матеріалу шарів, як випадкової величини.
RU: АННОТАЦИЯ Диссертация посвящена решению научной проблемы повышения ресурса и на-дежности эксплуатации железнодорожного подвижного состава при ремонте. Ре-монтное производство является важным звеном обеспечения эффективного функ-ционирования подвижного состава, но при этом требует значительных финансовых затрат. Учитывая, что ремонтное производство существенно влияет на экономичес-кие показатели работы подвижного состава, в диссертационной работе была поста-влена задача – разработать или усовершенствовать технологии восстановления на основе наиболее распространенных в ремонтном производстве железной дороги, а именно наплавки, газотермического напыления и электролитических методов. То есть согласно идеологии работы необходимо обеспечить максимально возможную надежность и определенный ресурс деталей подвижного состава при минимальных затратах. Среди деталей механической части подвижного состава на основе анализа условий эксплуатации, степени износа, количества элементов и стоимостных показателей выделены типичные по взаимодействию группы деталей и иссле-дованы механизмы изнашивания контактных поверхностей. Для выделенных деталей установлены закономерности изменения параметров состояния в про-цессе эксплуатации. Поставлена и решена задача по установлению связей между параметрами технологических процессов восстановления деталей подвижного состава желе-зной дороги, структурой и свойствами слоистых покрытий. В работе показано, что регулируя параметры технологического процесса нанесения покрытий, мо-жно получать слои с заданными (ожидаемыми) свойствами. Установлено, что для получения композиционного слоистого покрытия методами наплавки и га-зотермического напыления наиболее целесообразно использовать различные материалы, комбинируя их в зависимости от потребностей ремонтного произ-водства. Получение слоистости покрытий электролитическими методами наи-более целесообразно путем изменения электрических режимов источника пита-ния и в меньшей степени, комбинируя слои, полученные в различных электро-литах, из различных материалов. Отмечено, что слоистое покрытие можно представить в виде реологической модели, что позволяет применять реологиче-ские модели при исследовании износа контактирующих тел, а также использо-вать предложенные способы для измерения реологических свойств тел (слоев) восстановленных деталей. Разработана и представлена в диссертационной работе математическая мо-дель по определению рациональных параметров восстанавливающего слоисто-го покрытия деталей подвижного состава при ремонте, которая позволяет пред-приятию устанавливать рациональные режимы и технологию восстановления изношенных деталей с учетом стоимостных показателей процесса. Установлено влияние вариации толщины слоев и их механических свойств на срок службы. Показано, что в зависимости от поставленных задач, используя разработанные модели, можно подбирать слои таким образом, чтобы восстановленная деталь работала установленный срок (пробег) при минимально возможных при этом затратах. Используя инструменты векторной оптимизации, предложен алгоритм оценки качества восстановления деталей подвижного состава по нескольким показателям. Разработан алгоритм проведения расчетов при заданных начальных условиях, что позволяет спрогнозировать ресурс и стоимость нанесенного покрытия без прове-дения дополнительных, нередко, дорогих испытаний. Разработаны рекомендации относительно выбора режимов, технологии и техники восстановления изношенных деталей подвижного состава слоистыми покрытиями, обеспечивающими высокое качество и надежность эксплуатации выбранных деталей. Предложена методика оценки надежности работы деталей, восстановлен-ных слоистыми покрытиями, которая позволяет определять вероятность безот-казной работы этих деталей с учетом износа материала слоев, как случайной величины.
EN: ABSTRACT The thesis is devoted to solving the scientific problem of increasing the service life and reliability of operation of rolling stock during its repair. The problem of determining the relations between the parameters of technological processes for recovery of railway rolling stock parts, the structure and the properties of layered coatings is formulated and solved. It is shown in the thesis that by adjusting the parameters of the coating technological process of depositing the layers can be obtained with the specified (anticipated) properties. A mathematical model to determine the rational parameters of recovering layered coating of the rolling stock parts during a repair, which enables the company to set rational modes and technology of recovering the worn taking into account the cost indices of the process is developed and presented in the thesis. Using the vector optimization instruments, an algorithm for assessment of the quality of recovering the rolling stock parts in several indices is suggested. The recommendations on the choice of modes, technologies and techniques of recovering the worn rolling stock parts by the layered coatings ensuring the high quality and reliability of operation of parts selected are developed. The procedure for estimating the reliability of parts recovered by layered coatings, which allows determining the probability of failure-proof operation of these parts taking into account the wear of material of the layers as a random value, is suggested.
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McAfee, James. "Wear resistant coatings for agricultural wear applications." 1986. http://catalog.hathitrust.org/api/volumes/oclc/15473362.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1986.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 63-67).