To see the other types of publications on this topic, follow the link: Karbidy.
Dissertations / Theses on the topic 'Karbidy'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Karbidy.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Salajka, Jaroslav. "Slinuté karbidy a jejich efektivní využití." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228627.
Full textAbstract:
The aim of this thesis is a complex processing of obtained technical findings in the area of cutting materials, especially the evaluation and comparison of work possibilities recommended by prime world manufacturers for effective usage and application of coated and uncoated cemented carbides. Characteristics of cemented carbides in terms of production, marking method, physical and mechanical properties and application. Comparison of cemented carbides in the range of production of the most significant world tool and cutting material producers. Cutting efficiency evaluation of the tool. Recommended areas and operating conditions for effective usage of cemented carbides and their technical economic evaluation.
2
Dembek, Jiří. "Slinuté karbidy a jejich efektivní využití." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229215.
Full textAbstract:
This diploma thesis is aimed on cutting tools made of cemented carbides. It characterizes marking, production and properties of non-coating and coating cemented carbides and describes the latest trends in coating. Target of this diploma thesis is comparison of assortment of two important world’s producers and one Czech producer in term of used productive technologies, products microstructure, coatings types, coatings methods and possibilities of their usage. Cutting data were evaluated and compared from obtained technical knowledge, which were recommended by chosen producers for effective turning application of their cutting tools. Recommended cutting speeds were found out for specific type of cutting material according to ISO, width depth of cut and for specific values of feeds per revolution.
3
Baran, Jan. "Slinuté karbidy a jejich efektivní využití." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228005.
Full textAbstract:
The diploma work deals with comparison of sintered carbides in product assortment of Pramet Tools a.s., Sandvik-Coromant and Ceratizit companies in term of their cutting speed, feed and depth of cut for the turning operation. The comparison of cutting parameters is made for P, M, K, N, S and H groups. For better comparison there are always two sintered carbides from each of the manufacturers mentioned for each of the groups P, M, K. They are mentioned for groups N, S and H only if they are suggested by the manufacturer.
4
Pavlovský, Tomáš. "Povlakované slinuté karbidy a jejich efektivní využití." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230359.
Full textAbstract:
This thesis deals with coated cemented carbides, which are used for the manufacture of cutting tools. The introductory section provides an overview of the most common tool materials. The main part focuses on the production of coated SK, coating methods, types and properties of coatings. The final section deals with coated cemented carbide product range in the world's leading producer of tools and tool materials, tools and recommended working conditions for their effective use.
5
Stavinoha, Petr. "Nástroj pro vrtání stavebních materiálů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228422.
Full textAbstract:
This thesis deals with the analysis of drilling technology of building materials and design of drilling tools. The thesis analyzes a given cutting materials and usability their applications for drilling of building materials. Further, the thesis deals with the creation of 3D model of drilling tool in SolidWorks environment and preparation of CNC program for cutting centre SP 208 SY which is controlled by Sinumerik system.
6
Mangl, Petr. "Optimalizace parametrů broušení slinutých karbidů diamantovými kotouči." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228780.
Full textAbstract:
This master‘s thesis is presenting the way of the optimization of grinding characteristics when grinding cemented carbides by diamond wheels. There is described the theory of grinding, including grinding wheels and basic characteristics of cemented carbides in the theoretical part. There are defined experimental metering accomplished on the CNC grinding machine Walter Helitronic Power Mini in the practical part. There were tested eight grinding wheels. The grinding rate, surface roughness Ra, theoretic guaranteed storage period of grinding wheel in number of cuts, theoretical capacity of machined material, achievement of grinding machine and behaviour of the wheels when grinding ware evaluated from the reached results.
7
Smrž, Peter. "Odolnost slinutého karbidu vůči vzniku a šíření tepelných trhlin." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230951.
Full textAbstract:
This thesis aims to compare the relationship of physical-mechanical properties of tool materials made of WC-Co sintered carbides with their resistance to initiation and propagation of thermal cracks. The paper presents the results of testing the basic physical-mechanical properties of the three samples sintered carbides with different percentage of Co binder. Next, this thesis describes the progress and results of quench experiment and cutting tests using, which was described resistance of the tested samples to thermal and mechanical shock, depending on the values of physical-mechanical properties.
8
Uttendorfský, Aleš. "Studium řezivosti celokarbidových fréz s jemnou zrnitostí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229073.
Full textAbstract:
This diploma thesis consists of two parts. The theoretical part describes sintered carbides, their properties and manufacturing tools. Some selected problems of milling and its physical nature is discussed also. It also deals with the types and methods of tool wear testing. The aim is to compare the experimental properties of monolithic end milling cutters (short four cutting edges, uncoated carbides) of various grain sizes in two basic ways of milling - down-feed method and up-feed method. The measured values are evaluated by analysis in time series of the cutting forces and power.
9
Král, Ondřej. "Optimalizace řezného procesu pro obrábění hliníkového profilu na CNC obráběcím centru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-402563.
Full textAbstract:
This master‘s thesis deals with the suggestion of suitable tools for milling aluminum alloys profiles for the construction of aperture fillings and their aplication to a CNC machining center for increasing the efficiency of the cutting process. The first part of the thesis is focused on the description of the company and the workplace of production of aluminum alloys constructions. The following pages contain description of standardized products, which are used to identify the test profile that is part of the experimental verification. Next part of this thesis is characteristic of aluminum alloys and tool materials suitable for their machining. Second part of this work contains an analysis of the current state, suggestion of new cutting tools and their application to the production proces. At the end of this thesis there is the technical-economic evaluation that deals with the time and economic savings of the applied design.
10
Vopařil, Josef. "Moderní řezné nástroje ze slinutých karbidů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228549.
Full textAbstract:
This thesis is focused on cutting tools made of cemented carbides. It contains analysis of cemented carbides for uncoated and coated cutting tools. It contains examples of modern tools for turning, milling and drilling. Practical part of this thesis evaluates and compares cutting properties of two types of spiral drills.
11
Balko, Michal. "Sušení koksu pro výrobu karbidu vápenatého." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230834.
Full textAbstract:
The thesis deals with analysis of calcium carbide production process. The aim of the thesis is to identify and design savings resulting from the use of energy contained in flue gas, which is produced during the process. In the first part, history and applications of calcium carbide are presented. The thesis then contains mass and energy balance of calcium carbide production. Balance is related to 1 ton of the product. In conclusion, possibilities of flue gas use for coke drying are proposed. The thesis is based on the information from the calcium carbide factory located in Sundsvall, Sweden.
12
Štefek, Jaromír. "Moderní řezné nástroje ze slinutých karbidů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-228932.
Full textAbstract:
This thesis deals with modern cutting cemented carbide tools. In the first section are stated several basic innovations already used tools for basic machining operations, which is turning, milling and drilling. It continues with analysis of single materials for production of cemented carbides, non coated as well as coated and with comparing of their properties. There are listed the basic cutting properties of the cutting tools after that. The penultimate point of the work is optimization of the basic machining operations, namely roughing and finishing, for a given application, which is in this case turning on the lamp stand. Finally, everything is summed up and evaluated in the conclusion.
13
Nováková, Radana. "Povlakování střižných nástrojů ze slinutých karbidů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231749.
Full textAbstract:
Tato diplomová práce se zabývá problematikou PVD povlakování střižných nástrojů ze slinutých karbidů, se zaměřením na zvýšení životnosti postupových nástrojů. Především poukazuje na využití povlakovaných nástrojů v praxi a procesních kroků před a po procesu povlakování. V teoretické části jsou popsány obě základní metody povlakování, tj. fyzikální metoda PVD a metoda CVD, založena na chemickém procesu. Dále jsou představeny jednotlivé způsoby vlastních procesů povlakování se stručným popisem výhod i nevýhod jejich využití. Praktická část je zaměřena na testování, jehož podstatou byl nejen vhodný výběr samotného povlaku pro daný materiál, ale i úpravy před a po povlakování, které jsou často opomínány. Ty jsou však nezbytnou součástí a mají výrazný vliv nejen na výsledný povlak, ale i na kvalitu pracovního procesu. Vyhodnocením experimentu je souhra určení nejproduktivnějšího povlaku v závislosti na dané úpravě.
14
Vaněček, Stanislav. "Cermety a jejich efektivní využití." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228623.
Full textAbstract:
The Thesis described within the scope of the Master Program is focused on cermets, which belong among cutting materials. The introductory portion of the Thesis presents the characteristics of cermets from the perspective of production, physical-mechanical characteristics, marking and usage in cutting. The core portion of the Thesis focuses on the role of cermets in the category of leading world producers of tools and instrumental materials, cutting evaluation, and the suggested working conditions of cermets in lathing operations. The working conditions are prepared for steel and cast iron. The conclusion of the Thesis focuses on a technical-economical analysis of cermets.
15
Pavelka, Rudolf. "Analýza vyměnitelných břitových destiček ze slinutých karbidů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229273.
Full textAbstract:
This study states basic technological aspects of metal machining with cutting inserts, with special stress on coated carbide cutting inserts. Among others, it states wear-out theory incl. wear-out accompaniments, problems of chip-forming and other factors of metal machining. At the end of the study, it contents a description of the latest cutting materials and construction elements of cutting inserts from reputable producers and, for some of them, also the course and the results of practical tests and comparison.
16
Doležalová, Petra. "Vlastnosti povlaků řezných nástrojů ze slinutého karbidu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230904.
Full textAbstract:
Diploma thesis is divided into two parts. The first part is focused on theoretical description of coating methods, on currently used coatings, their properties and it is also focused on description of methods, which are used for analyzing each property. The second part focuses on testing of coatings and analyzing of the values obtained from experiments. The aim of this thesis is then to compare the properties of the tested coatings.
17
Tlapák, Michal. "Technologické, ekonomické a ekologické aspekty použití mazání mlhou." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228837.
Full textAbstract:
The assessment of MQL technology application in reaming process was elaborated in this diploma work. The evaluation of energy intensity was carried out in terms of specific cutting force during reaming of austenitic stainless steel work piece by using HSS reamers. The comparison of economic costs in the case of the application of MQL technology in production was made. Confrontation of oil mist removal principles. At the conclusion the evaluation of ecological benefits for the environment and the positive influence on the working environment cleanness was defined.
18
Gabriel, Petr. "Spínaný zdroj 5,5kV/4,3kW s polovodiči z karbidu křemíku." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219930.
Full textAbstract:
This thesis is about to introduce the development of switched power supply with output voltage of 5,5 kV and power of 4,3 kW. This thesis directly follows the outputs of two previous semester projects. Main task is about to finish the development of remaining printed circuit boards and perform launching of all parts of developed power supply. Next necessary task is about to assemble a functional prototype of the supply using the developed parts, performing a series of measurement supply’s parameters and creating of technical documentation of mechanical part. There are all stages of supply’s development included in this thesis. From the first part, that describes various types of converters, through the design of all the supply’s parts, to final implementation of functional prototype. There are the results of measurement supply’s parameters at the end of this thesis.
19
Kocúrek, Ondřej. "Optimalizace použití břitových destiček na lince plášťů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228621.
Full textAbstract:
This thesis deals with a summary of different types and characteristics of coatings used for increasing the lifetime of cemented carbide tools. Besides, the thesis includes solving the issue regarding edge chipping during machining interrupted pipe ends at the pipe line, selecting a new type of indexable inserts and indexable inserts holders to increase line productivity and decrease tool costs in the related operation.
20
Pavézka, Vladimír. "Analýza dokončovacích způsobů obrábění." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229963.
Full textAbstract:
This eleborate study is aimed at analysis of complete methods machining. There are characterized particular methods and their effect on the surface´s quality of machined area in this study. Concluding part of the study includes practical demonstration of machining by using cemented carbide-tipped tool and polycrystalline diamond and evaluation of this demonstration.
21
Hudeček, Pavel. "Testování řezivosti nástrojů ze slinutých karbidů povlakovaných PVD nanokrystalickými kompozity." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228680.
Full textAbstract:
This thesis deals with the analysis of properties of hard coatings and wear resistance PVD coated technology. It focuses on the preparation, execution and evaluation of test coatings on the front ball milling cutter.
22
Tuna, Jaroslav. "Metody povlakování řezných nástrojů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230106.
Full textAbstract:
This diploma thesis is aimed on methods of the coating cutting material (cemented carbide, cermets, cutting ceramic, super hard materials) and evalutation individual method regarding technological posibilities of deposition of hard coatings a their mechanical, thermal and che-mical properties. The task of the work is full elaboration obtained technical knowledges and mainly evalutation a comparison of the work conditions (kind of the cutting materials, cutting conditions) that selected producers recomended for effective turning aplications of the coa-tings cutting materials.
23
Koubek, David. "Analýza silového zatížení při obrábění hliníkových slitin monolitními frézami ze slinutého karbidu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241851.
Full textAbstract:
The aim of this thesis is to create the proposal and expansion of knowledge in the field of experimental measurement of force load when milling thin-walled parts made of aluminum alloy monolithic cylindrical shank cutter of cemented carbide (hereinafter referred to as CC). It also discusses the theoretical analysis of the forces generated during milling, and practical approaches to their measurement experiments. This work also deals with the analysis of aluminum and its alloys. The next chapter describes the appropriate strategy for the machining of thin-walled components including defining the problems, that can complicate machining thin walls. The practical part deals with prediction and a following suggestion of the experiment measuring the power load. The last section is devoted to the practical implementation of the measurement of forces during the milling of thin-walled parts with subsequent evaluation and comparison of strength for the record selected from CC carbide tools, including evaluation of roughness parameters.
24
Čermák, Jaromír. "Soudobé otěruvzdorné povlaky a jejich vliv na efektivní využití řezných nástrojů ze slinutých karbidů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-233864.
Full text
25
Konnerth, Linda. "A Grammar of Karbi." Thesis, University of Oregon, 2014. http://hdl.handle.net/1794/17928.
Full textAbstract:
Karbi is a Tibeto-Burman (TB) language spoken by half a million people in the Karbi Anglong district in Assam, Northeast India, and surrounding areas in the extended Brahmaputra Valley area. It is an agglutinating, verb-final language.
This dissertation offers a description of the dialect spoken in the hills of the Karbi Anglong district. It is primarily based on a corpus that was created during a total of fifteen months of original fieldwork, while building on and expanding on research reported by Grüßner in 1978. While the exact phylogenetic status of Karbi inside TB has remained controversial, this dissertation points out various putative links to other TB languages.
The most intriguing aspect of Karbi phonology is the tone system, which carries a low functional load. While three tones can be contrasted on monosyllabic roots, the rich agglutinating morphology of Karbi allows the formation of polysyllabic words, at which level tones lose most of their phonemicity, while still leaving systematic phonetic traces.
Nouns and verbs represent the two major word classes of Karbi at the root level; property-concept terms represent a subclass of verbs.
At the heart of Karbi morphosyntax, there are two prefixes of Proto-TB provenance that have diachronically shaped the grammar of the language: the possessive prefix a- and the nominalizer ke-. Possessive a- attaches to nouns that are modified by preposed elements and represents the most frequent morpheme in the corpus. Nominalization involving ke- forms the basis for a variety of predicate constructions, including most of Karbi subordination as well as a number of main clause constructions. In addition to nominalization, subordination commonly involves clause chaining.
Noun phrases may be marked for their clausal role via -phān `non-subject' or -lòng `locative' but frequently remain unmarked for role. Their pragmatic status can be indicated with information structure markers for topic, focus, and additivity.
Commonly used discourse constructions include elaborate expressions and parallelism more generally, general extenders, copy verb constructions, as well as a number of final particles.
Audio files are available of the texts given in the appendices, particular examples illustrating phonological issues, and phonetic recordings of tone minimal sets.
Supplemental files are located at: https://scholarsbank.uoregon.edu/xmlui/handle/1794/13657
26
Kuzdas, Jan. "Nové koncepce výkonových pulsních měničů s použitím extrémně rychlých spínacích polovodičů na bázi karbidu křemíku." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-233651.
Full textAbstract:
This work deals with high power pulse converters (tens of kW) using new semiconductor devices of silicon carbide (SiC). Firstly the current state of the issue is analyzed. A research in a specific area of high power buck converters with pulse transformer follows. There was a strong emphasis on minimizing size and weight. The design process was focused also on reliability and robustness. To achieve the defined objectives, it was necessary to use the latest available switching transistors and diodes, and an unusually high switching frequency (100 kHz at a power of about 16 kW). Due to the high switching frequency, we achieved small size of pulse transformers and output chokes. An optimization of high-frequency pulse transformer with demand on minimum volume and weight of core and windings represents a separate theoretical part of the thesis. There have been proposed several analytical solutions of optimization problems, the results of which could overlap with the implementation in practice of switching power supplies. The combination of high switching frequency, fast semiconductors and the high power brings various parasitic effects to the power circuit. In the thesis, these parasitic effects are analyzed. Solutions which minimize or completely remove those effects were theoretically designed and successfully implemented, tested and finalized in experimental part of the work. Detailed description of the implementation of functional sample and series of validation measurements are included in the final part.
27
Grom, Martin. "Experimentální blokující spínaný zdroj 1200 W/ 150 kHz s polovodiči SiC." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221180.
Full textAbstract:
This master’s thesis deals with design and construction of experimental flyback converter with utilization of novel lossless clamp circuit for switching transistor and with utilization of silicon carbide devices. The issue of flyback converter for higher power and possible control strategies are discussed. The thesis also describes power and control circuits design, design of PCB, construction of the converter and measured waveforms. End of the thesis contains technical documentation of designed board. Designed converter was successfully built and tested.
28
Pagáč, Aleš. "Návary proti opotřebení." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231436.
Full textAbstract:
The subject of this Diploma thesis was study of wear resistant deposits, including appropriate basic and filler materials and welding technologies suitable for a particular application of hard carbide overlays of blade mixer for foundry sand. Analysis of suitable filler materials focused on extreme abrasion and select tungsten carbide hardfacing, together with a selection of appropriate overlays welding methods for welding tungsten carbide, including the conditions and parameters surfacing. The practical part deals with the design and evaluation of the experiment, three samples welding of non-alloy structural steel, tungsten-carbide hardfacing, technology MCAW - WC flux cored electrode in protective active gas.
29
Bogdanovski, Dimitri [Verfasser], Richard Akademischer Betreuer] Dronskowski, and Ullrich [Akademischer Betreuer] [Englert. "Quantenchemische Untersuchungen der Nahordnungseffekte und etwaiger Fehlordnung in κ-Karbiden / Dimitri Bogdanovski ; Richard Dronskowski, Ullrich Englert." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1190360853/34.
Full text
30
Le, Moine Rebecka. "The land use cover changes from 1992 to 2011 in Karbi Anglong, Assam, India." Thesis, Linköpings universitet, Ekologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-79347.
Full textAbstract:
With an increased human impact, natural resources are under great pressure. Deforestation is one effect of this, and the largest threat against biodiversity.. Changes in tropical habitats is a major concern for conservation biologists, due to its high biodiversity and rapid decreased area. Recently, developmental activities and habitat destruction have caused a major decline in the abundance of the terrestrial mega-fauna.This is especially evident in areas with a high human population and a rich mega-fauna as in India. The purpose of this project was to determine the land-use cover change (LUCC) in the area of Karbi Anglong, which lies in the middle of Assam, India. This was done by identifying different vegetation types from satellite images, from the years 1992, 2002 and 2011 using a remote sensing application (ERDAS) and ArcGIS. Interviews in the area werealso operated, and data about how animal use the corridors were used along with registered human-tiger conflicts. The results show that during the first period, a total of 360 km2 of the area changed vegetation type, mostly due to an increase of agricultural areas. The second largest change (79 km2) was an increase of moist mixed deciduous forest which seems to have taken over some of the semi evergreen forest’s previous area. If that is the case it is most likely an effect of selective logging from the local people, who use fire wood as fuel.All in all, there has been a great habitat loss along withfragmentation of the landscape. The conflict data shows that tigers are present between the core areas, and the interviews show that the migrations of other animals are also common.To maintain the high ecological values in Karbi Anglong, it is of great importance to maintain connectivity between core areas and stop further habitat loss and fragmentation.
31
Štěpánek, Martin. "Návrh technologie vystružování." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-317199.
Full textAbstract:
The diploma thesis deals with the design of the hole-making technology for hydraulic components that are specific for its high requirements on size and shape accuracy. The aim of diploma thesis is to compare the productivity, efficiency and accuracy of reaming with two different reamers – the solid carbide reamer and the newly designed reamer that combines two cermets on cutting part of the tool. In the practical part, the data analyses and calculations were made. It was discovered that the newly designed tool brings economic benefits while the qualities of final hole are improving or remaining at the same level.
32
Rusz, Radek. "Technologie výroby kombinovaných řezných nástrojů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230013.
Full textAbstract:
In the thesis is solved manufacturing technology of step drill from material of cemented carbide. At first is made review of existing shank cutting tool types, after that follows an analysis of cemented carbide tool material. In the next part of thesis is manufacturing technology of this tool, including review of grinding wheels, designed. Output of this work is procedure of program designing for manufacturing this tool in software Numroto. Next output is techno-economic evaluation of step hole manufacture with combined tool and comparison to conventional type of manufacture.
33
Stratil, Luděk. "Vysokoteplotní provozní zkřehnutí oceli EUROFER´97." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228854.
Full textAbstract:
The thesis describes effect of long-time ageing on the microstructure and properties of the Eurofer´97 steel. The ferritic-martensitic reduced activation steel Eurofer´97 is candidate structural material for in-core components of proposed fusion reactors. Thesis is focused on examination and description of brittle-fracture behaviour of the steel. Properties of the steel were investigated in as-received state and state after long-time ageing. Detailed microstructure studies were carried out by means of optical and electron microscopy and also by means of quantitative electron microscopy. Mechanical properties were evaluated also in both states by means of hardness tetsing, tensile testing and Charpy impact testing. Fractography analysis of fracture surfaces was carried out on samples after Charpy impact testing.
34
Jašek, Petr. "Vliv PVD povlaku na trvanlivost VBD při čelním frézování." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241920.
Full textAbstract:
This diploma thesis is aimed on durability of PVD and CVD coatings for symmetrical face milling. The theoretical part describes the characteristics of cemented carbides, milling technology and the characteristics of the coating methods. The experimental part describes the machine tool, used tools, workpiece material and cutting conditions. The aim of the work was to measure the cutting forces and tool wear during the milling. Based on experiment, it is clear that the PVD coatings with nano-layers achieves to the longer life in comparison with others and generally, that the using of coatings leads to reduction of cutting powers and lifetime was increased.
35
Zdařil, David. "Technologie výroby vybraného sortimentu nástrojů s aplikací vysoce produktivního výrobního zařízení." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417150.
Full textAbstract:
The aim of this work is to analyze the issue of providing cutting tools for internal use in the company STERCH-INTERNATIONAL s.r.o. It is mainly the production and regrinding of end mills and drills for specific machining applications, whose benefit lies in increased efficiency and flexibility of production, which also brings a significant cost reduction.
36
Skokan, Jan. "Vliv plastifikátoru na technologii zpracování a vlastnosti slinovaného keramického mateiálu na bázi SiC." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231997.
Full textAbstract:
This master’s thesis deals with an influence of physical properties and machining technology at adjustment to the basic composition granules and production of technical ceramics. Selected series of experiments have been applied to the different phases of production. Composition of the granules vary according to the used plasticizer and ranks to RTP (ready-to-press) materials. The goal of this thesis is recomendation to the production of RTP granules and next experiments.
37
Holub, Miroslav. "DC-DC měnič pro palubní dobíjení elektromobilu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-401968.
Full textAbstract:
This master thesis deals with design of DC-DC converter for onboard charging of electric vehicle. Developed converter will mainly be used for charging stationary traction battery in laboratory. Output voltage of this charger will be adjustable by user in between 200 V and 450 V depending on the current charged battery configuration. Output current limit is set at 8 A. Since the converter will be supplied from standard household socket, the problem of power factor correction must be solved during the design. That is because a large part of this thesis is focused on describing the problematics of power factor correction. After that, active PFC module is designed, completed and performance of this module is verified. To achieve low overall losses and thus be able to keep small volume of the system, modern switching components based on Silicon Carbide were preferred. Beside laboratory use, completed system will be used to emphasize volumetric difference between onboard chargers based on old versus modern switching components.
38
Bendikas, Romas. "Gręžimo režimų įtaka skylių stiklo tekstolite paviršiaus kokybei." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20090702_141359-55419.
Full textAbstract:
Darbas skirtas skylių gręžimo stiklo tekstolito plokštėse kokybės užtikrinimo problemoms spręsti. Teoriškai išanalizuoti įvairūs gręžimo būdai: mechaninis, lazerinis, plazminis. Išdėstyti pagrindiniai faktoriai, lemiantys skylių kokybinius parametrus.Eksperimentinis tyrimas buvo atliekamas Tauragėje AB „Telga“, gręžimo ceche. Programinėmis gręžimo staklėmis TIMAX MDR 2002 gręžtas stiklo tekstolitas FR–4, skirtingais pjovimo režimais. Mikroskopu įvertinta įvairiais režimais ir grąžtais gautų paviršių kokybė. Išaiškinti optimalūs darbo režimai priklausomai nuo skylių kokybės keliamų reikalavimų.This work deals with the quality problems of hole drilling in the glass textolite panels. Different drilling methods: mechanical, laser based and plasmic drilling have been analysed theoretically. The main factors, determining qualitative parameters of holes, have been stated. Experimental study has been performed in Tauragė, AB „Telga“ drilling workshop. Glass textolite FR–4 has been drilled using programmable drilling machine TIMAX MDR 2002 and applying different cutting modes. The quality of surfaces obtained after drilling by different modes and drills has been evaluated by using microscope. Optimal performance modes depending on the requirements for the quality of holes have been explored. The work consists of four parts: introduction, literature review, experimental analysis and conclusions.
39
Borchardt, Lars. "Carbide and Carbide-Derived Carbon Materials with Hierarchical Pore Architecture." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-107865.
Full textAbstract:
This thesis addressed the development of new porous carbides and carbide-derived carbons; in particular materials based on silicon-, boron-, tungsten-, and titanium carbide. Therefore, different hard- and soft-templating approaches were applied and the materials were additionally functionalized with catalytic active components and shaped into nm- and mm-sized spherical particles.
40
Gábor, Radek. "Aplikace elektroerozivního hloubení při technologii výroby vyměnitelných břitových destiček SK." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228099.
Full text
41
Beck, Branislav. "Nízkoteplotní zkoušky a lomová houževnatost vybraných keramických materiálů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231786.
Full textAbstract:
Diploma thesis deals with the determination of fracture toughness values of sintered silicon carbide and casted basalt using both the Single Edge V-Notch Beam (SEVNB) and the Chevron Notched Beam (CNB) methods at room and cryogenic temperatures. The first part of this thesis offers general overview and categorization of ceramic materials. Fracture mechanics of the ceramic materials and available fracture toughness testing methods are discussed in following chapters. The last section in the theoretical part is aimed to the microstructure and properties of the silicon carbide. Experimental part of the work summarizes methods used for characterization of selected materials from the microstructural and fracture point of view. Preparation of samples for microstructural observation and samples for fracture toughness determination are described in details. The results of the fracture toughness data for sintered silicon carbide and cast-basalt obtained at room temperature and at -100 °C are displayed. Consideration of possible measurements errors and application of various fracture toughness testing methods are discussed in the next chapter of this work. The difference in the fracture toughness values with the decrease of testing temperature was found. The difference depends on both, the used method of fracture toughness determination and the material used for the tests. The most important results gained during the experimental work are summarized in the chapter “Conclusions”.
42
Černín, Jiří. "Zvýšení životnosti náhradních dílů strojů zpracujících půdu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400972.
Full textAbstract:
This diploma thesis deals with increasing the service life of parts intended for soil cultivation. The work evaluates the current possibilities of increasing the utility value of spare parts. Practical tests will provide recommendations for the most appropriate method to increase durability. The work examines uncharted methods of testing soldered joint. The results are evaluated in terms of quality and economic profitability. All results from this work are based on the basis of practical tests of plowing machine in rocky soil.
43
Kudrna, Tomáš. "Elektroerozivní hloubení technické keramiky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417445.
Full textAbstract:
The master’s thesis deals with the topic of electrical discharge machining. The first part of the thesis contains a study of the die-sinking EDM. The die-sinking EDM of the silicon carbide ceramic is realized in the experimental part of the thesis. The result of this work was to explore the influence of the EDM sinking parameters, specifically pulse current, open-voltage and pulse on-time, on the machined surface. Furthermore, the analysis of the tool electrode was made. This analysis was focused on the wear in the corners, which has key influence on accuracy of the machining. The machining time was also examined.
44
Jankůj, Luděk. "Svařování ODS materiálů elektronovým svazkem." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254219.
Full textAbstract:
Thesis on Electron beam welding of ODS materials is divided into theoretical and experimental part. In the first part the theoretical research work focuses on the accurate description of the candidate materials in a research fusion reactor ITER. Following are detailed constructional ODS materials and tungsten alloy as a material of the first wall. The second part of the theoretical research deals with various possibilities of joining high-melting dissimilar materials such as brazing or electron beam welding as well, which will be established in the experimental section. The experimental part of the thesis deals with a joining ODS steel MA 956 with sintered carbide WC-Co and ODS tungsten. These materials are welded by electron beam. Individual samples are distinguished used filler material, preheating or welding parameters. This thesis contains photographic documentations of microstructure the welding samples, results from scanning electron microscopy, and measurements of microhardness across the weld metal.
45
Bojana, Vasiljević. "Mikrotalasno stimulisana sinteza odabranih derivatanaftenskih i žučnih kiselina, ispitivanje njihove biološke aktivnosti kao i termičke i hemijske stabilnosti odabranih lekova." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2014. https://www.cris.uns.ac.rs/record.jsf?recordId=87894&source=NDLTD&language=en.
Full textAbstract:
Predviđena istraživanja u ovoj doktorskoj disertaciji su usmerena upravcu iznalaženja novih, efikasnijih i bržih mikrotalasno-stimulisanihmetoda hemijskih transformacija koje ne uključuju prisustvokatalizatora i/ili organskih rastvarača. Primenom specijalnih silicijum-karbidnih reakcionih sudova, brzina i preciznost izvođenjamikrotalasno-stimulisanih transformacija prikazana je kroz stresnestudije aktivnih farmaceutskih ingredijenata u SiC ploči, odnosnoHPLC/GC vialima kao reakcionim sudovima. Ispitano je postojanjenetermičkih mikrotalasnih efekata i njihov značaj za precizno tumačenjerezultata mikrotalasne sinteze.U drugom delu ove doktorske disertacije izvršena jemikrotalasno-stimulisana sinteza potencijalno biološki aktivnih supstanci iz prirodnihlako dostupnih materijala kao što su naftenske kiseline. Sintetizovani suamidi i estri individualnih i prirodnih naftenskih kiselina Velebit.U radu je takođe ispitana biološka aktivnost sintetizovanih derivata.Proučavan je uticaj prirodnih naftnih kiselina Velebit injenih derivatana rast pet sojeva Pseudomonassp., kao i uticaj odabranih sintetisanihjedinjenja na proliferaciju pet ćelijskih linija humanih tumora pri čemuje kao kontrola služila jedna zdrava humana ćelijska linija.Scientific research predicted in this PhD thesis isdirected to ascertainment new, efficient and faster microwave-assisted methods of chemical transformations in the absence of catalysts and/or organic solvents. Applaying special silicon-carbide reaction vessels, speed and accuracy of microwave-assisted transformations are ilustrated within stress testing of active pharmaceutical ingredients in HPLC/GC vials placed in SiC plate. Existence of nonthermal microwave effects and their influence on accurate interpretation of microwave synthesis results are also investigated. In the second part of this thesis microwave-assisted synthesis of potentionally biologically active compounds from readily available natural materials, such as naphthenic acid is accomplished. Amides and esters of individual and natural naphthenic acids Velebitare synthetised. The thesis also examined the biological activity ofthe synthesized products. The effect of natural petroleum acids Velebitand its derivatives are examined on the growth of five strains of Pseudomonas sp., and the impact of selected synthesized compounds on the proliferation of five human tumor cell lines in which a healthy human cell line is tused as the control.
46
Safara, Nosar Nima. "Modeling the Microstructure Evolution During and After Hot Working in Martensitic Steel." Licentiate thesis, Högskolan Dalarna, Institutionen för information och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-287278.
Full textAbstract:
In this study, the goal is to predict the microstructure evolution during and after the hot working of a martensitic stainless steel with 13% chromium using a physically-based model in the form of a MATLAB toolbox. This model is based on dislocation density theory and consists of coupled sets of evolution equations for dislocation, vacancies, recovery, recrystallization, and grain growth. The focus in this work is on the flow stress calculation and the effect of second phase particles on the strengthening mechanisms in the material at elevated temperatures. Recovery and recrystallization are also studied for this alloy during deformation and following stress relaxation. The experimental part of this work was performed with a Gleeble thermo-mechanical simulator over the temperature range of 850 to 1200°C. Samples were investigated later by a light optical microscope (LOM) and a scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscope (EDS). Hardness test and phase isolation were also performed on the samples and the results are compared with the modeling results. The model can satisfactorily predict the grain growth, recovery, recrystallization, and flow stress for this alloy. Further investigation on the second phase particles showed that the measured mean size of carbides has a good agreement with what is obtained from the model and the hardness values. On the other hand, the modeled volume fraction of the carbides followed a slightly different trend comparing to hardness values, and phase isolation results at temperatures higher than 1000°C. Additionally, the Ms temperature and fraction of the martensite phase are calculated for quenched samples where the results are following the measured hardness values. Finally, the Zener-Hollomon parameter (Z) and its relation to the flow stress and the activation energy for deformation are defined. The dynamic recrystallization (DRX) kinetic is modeled and the fraction DRX was calculated at various temperatures and strain rates for this alloy.I denna studie är målet att förutsäga mikrostrukturutvecklingen under och efter varmbearbetning i ett martensitiskt rostfritt stål med 13 % krom med hjälp av en fysisk baserad modell i form av en MATLAB verktygslåda. Denna modell är baserad på en teori för dislokationstäthet och bestårav kopplade uppsättningar av evolutionsekvationer för dislokation, vakanser, återhämtning, rekristallisation och kornstillväxt. Fokus i detta arbete är beräkning av flytespänningen och effekten av sekundärfaspartiklar på härdningsmekanismerna i materialet vid höga temperaturer. Återhämtning och rekristallisation studeras också för denna legering under deformation och efter spänningsrelaxation. Den experimentella delen av detta arbete utfördes med en Gleeble termomekanisk simulator inom temperaturområdet 850 till 1200°C. Proverna undersöktes senare med ett ljust optiskt mikroskop (LOM) och svepelektronmikroskop(SEM) utrustad med energidispersiv spektroskopi (EDS). Hårdhetstest och fasisolering utfördes också på proverna och resultaten jämförs med modelleringsresultaten. Modellen på ett tillfredsställande sätt kan förutsäga korntillväxt, återhämtning, rekristallisation och flytspänningen för denna legering. Vidare undersökning av partiklarna i sekundärfasen visade att den uppmätta medelstorleken för karbider har bra överensstämmelse med vad som erhålls från modellen och hårdhetsvärdena. Den modellerade volymfraktionen av karbiderna följde en något annorlunda trend vid temperaturerna högre än 1000°C jämfört med hårdhetsvärden och fasisoleringsresultat. Dessutom beräknas Ms temperaturen och fraktionen av martensitfasen för släckta prover där resultaten följer de uppmätta hårdhetsvärdena. Slutligen definieras Zener-Hollomon-parametern (Z) och dess förhållande till flytspänningen och aktiveringsenergin för deformation. Den kinetiska dynamiska rekristallisation (DRX) modelleras och fraktionen DRX beräknades vidolika temperaturer och töjningshastigheter för denna legering.
47
Tan, Hua. "Extrémně rychlé slinování pokročilých keramických materiálů." Doctoral thesis, Vysoké učení technické v Brně. CEITEC VUT, 2020. http://www.nusl.cz/ntk/nusl-414113.
Full textAbstract:
Techniky rychlého slinování jako „Spark Plasma Sintering (SPS)“, „Flash Sintering“ (FS), „Selective Laser Sintering“ (SLS), „Induction Sintering“ (IS) a „Microwave Sintering“ (MS) jsou navrženy tak, aby účinně a předvídatelně kontrolovaly mikrostrukturu během slinovací proces. Spark Plasma Sintering jako jedna z nejmodernějších technik rychlého slinování a byla studována po celá desetiletí. V SPS má tři hlavní rysy: přímý ohřev elektrickým proudem, pulzní stejnosměrný elektrický proud a mechanický tlak. Mechanismy působení faktorů během SPS procesu však nejsou zatím jasně objasněny. Tato práce byla inspirována zvýšeným zájmem o techniky rychlého slinování a snahou o objasnění působení hlavních faktorů. Tato studie je rozdělena do čtyř částí: efekt elektromagnetického pole, efekt pulzního vzoru, tlakový efekt a přímý Joulův ohřev. Výsledky ukázaly, že elektromagnetické pole v SPS může být ignorováno, jak ukázaly simulace, a rovněž během experimentů nebyl nalezen žádný „efekt pole“. Na druhou stranu účinek pulzního vzoru byl významný, prášek TiO2 byl slinován pulzními vzory 12:2 a 10:9 s konstantním příkonem. Po aplikaci pulzního vzoru 10:9 došlo ke zvýšení velikosti zrna o jeden řád a ke zvýšení hustoty o 8%, zatímco množství spotřebované energie zůstalo konstantní. Při zahřátí s různými vzory pulzů se mění účinný výkon a kontaktní odpor indukovaný mechanickým pulsem, což jsou dva hlavní důvody, které vysvětlují měnící se energetickou účinnost. Vliv tlaku byl také významný, výsledky ukázaly, že použití tlaku při 900 ° C přineslo vysokou hustotu a malou velikost zrn, což vedlo k nejvyšší tvrdosti měřenou podle Vickerse. Interakce mezi tlakem a parami, vedoucí k rozdílné rychlosti přenosu páry v prvním slinovacím stupni, je považována za důvod pro rozdíly v mikrostruktuře, jako jsou mikropóry. Načasování mechanického tlaku může také podporovat difúzní mechanismy zhutňování během druhého slinovacího stupně, jako je difúze na hranicích zrn a mřížková difúze. Přímý ohřev, kdy se vede elektrický proud přímo skrz vzorek, vede k nízké měřené teplotě při slinování karbidu boru a jeho kompozitů, avšak teplota uvnitř vzorku je podstatně vyšší. Přidání slitiny titanu a křemíku do B4C významně zvýšilo finální hustotu, což byl hlavní důvod ovlivnění mechanických vlastností. Vzorek B4C + 1.0Ti (1 obj. % Ti slitiny) dosáhl nejvyšší tvrdosti 3628.5 ± 452.6 HV1 (16.2% vyšší než čistý B4C) s lomovou houževnatostí 2.11 ± 0.25 MPa m0.5. Zatímco při dopování křemíkem dosáhl vzorek B4C + 0.5Si (0.5 obj. % křemíku) nejvyšší tvrdosti 3524.6 ± 207.8 HV1 (o 13.0% vyšší než čistý B4C), vzorek B4C + 1.0Si dosáhl nejvyšší lomové houževnatosti 2.97 ± 0.03 MPa m0.5 (o 15.6% vyšší než čistý B4C). Velikost zrn kompozitů dotovaných titanem se oproti čistému karbidu boru byla o něco větší a mikrostruktura více nehomogenní. Naproti tomu se velikost zrn vzorků dotovaných křemíkem příliš nezměnila ve srovnání s velikostí zrn čistého karbidu boru. Sekundární fáze karbid křemíku byla dobře spojena s matricí karbidu boru a vykazovala pozitivní účinek jak na tvrdost, tak na lomovou houževnatost. Tato práce zkoumala vliv různých kontroverzních a nepopsaných aspektů na slinování keramických materiálů metodou Spark Plasma Sintering, což vedlo k lepšímu pochopení této techniky slinování.
48
Siafakas, Dimitrios. "On deoxidation practice and grain size of austenitic manganese steel." Licentiate thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH. Forskningsmiljö Material och tillverkning – Gjutning, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-37788.
Full textAbstract:
The exceptional wear resistance and work hardenability, place Hadfield steel as one of themost important materials for manufacturing cast components used in the mining, crashing,drilling, and excavation industries. In all metallic alloys used for component casting, themechanical properties are highly influenced by the microstructure of the material. Castcomponents with finer microstructural characteristics are known to present bettermechanical properties and reduced risk of defects when compared with components witha coarser microstructure. A reduced grain size in Hadfield steel can increase the strengthof the material up to 30% and reduce the risk of porosity formation during solidification.The practice of adding selected compounds or alloying elements in a metal melt to modifyand refine the microstructure is called inoculation. It is currently one of the trendingmethods utilized in light-metal alloys and cast-iron components production but has not,yet, gained adequate acceptance in the steel casting industry because researchers have notbeen able to find proper inoculants.The main objective of this work is to investigate the qualitative and quantitativecharacteristics of the by-products of deoxidation of Hadfield steel that remain in thematerial after solidification and their positive or negative effect on the coarseness of thefinal as-cast microstructure. This type of research can help to identify the type of particlesor alloying elements that are most effective for refining the microstructure of austeniticsteels and pave the way for developing new or improving conventional deoxidation andinoculation processes that will, in turn, result in the improvement of the properties of thecomponent.The precipitation of particles and the as-cast grain size are studied in aluminum andtitanium deoxidized Hadfield steel samples acquired under pilot scale experimentalconditions. In the first part of this work, the qualitative and quantitative characteristics ofparticles such as type, morphology, composition amount and size are identified. Thesequence of precipitation is established. A model for predicting particle size and growth isdeveloped. The experimental results are compared against thermodynamic equilibriumcalculations and the precipitation mechanisms for each type of particles are described. Inthe second part, the as-cast grain size of samples with varying deoxidation treatments ismeasured. Then, the grain-size is correlated with certain particle characteristic and theparticles are ranked according to their ability to refine the microstructure. The particledisregistry with austenite is calculated and compared to the experimentally acquiredranking.Hadfieldstålen exceptionella slitstyrkan och deformationshårdnande har gjort dessa till ettav de viktigaste materialen för tillverkning av gjutna komponenter som används inomgruv-, kross-, borr-och gruvindustrin. I alla metallegeringar som används för tillverkningav gjutna komponenter styrs de mekaniska egenskaperna av materialets mikrostruktur.Gjutna komponenter med fin mikrostruktur presentera bättre mekaniska egenskaper ochminskad risk för defekter jämfört med komponenter med grov mikrostruktur. En minskadkornstorlek i Hadfieldstål kan öka materialets hållfasthet upp till 30% och minska riskenför porositetsbildning vid stelning.Tillsatsning av spårämnen eller legeringselement i en metallsmälta för att modifiera ochförbättra mikrostrukturen kallas ympning. Denna metod används i lättmetaller och vidtillverkning av gjutjärnskomponenter, men har ännu inte fått acceptans i stålindustrineftersom forskningen inte har funnit effektiva kärnbildare att användas som ympmedel.Huvudsyftet med detta arbete är att undersöka kvalitativa och kvantitativa egenskaper hosde desoxideringsprodukter som skapas under tillverkningen av Hadfield stål och hur deunder och efter stelning påverkar mikrostrukturens grovlek. Arbetet syftar till att identifierapartikeltyper och legeringselement som är effektiva för att förfina den austenitiskamikrostrukturen och bana väg för utveckling nya och förbättra desoxiderings- ochympningsprocesser som i sin tur kommer att resultera i en förbättring av den gjutnakomponentens egenskaper.Partiklarnas utskiljning och materialet resulterande kornstorlek studerades i aluminiumochtitan-desoxidiserade Hadfieldstål, tillverkade i pilotskala. Den första delen av dettaarbete var att identifiera kvalitativa och kvantitativa egenskaper hosdesoxidationspartiklar, som typ, morfologi, sammansättning och storlek.Utskiljningssekvensen fastställdes. En modell för att förutsäga partikelstorlek och derastillväxt utvecklades. De experimentella resultaten jämfördes med termodynamiskajämviktberäkningar och utskiljningen för varje typ av partikel beskrevs. I den andra delenstuderades kornstorleken och hur denna varierade desoxideringsbehandlingen. Därefterkorrelerades kornstorleken med partikeltyp och dess karaktäristika och rangordnades efterderas förmåga att förfina mikrostrukturen. Partiklarnas kristallografiska missanpassningmot austenitens kristallstruktur beräknades och jämfördes med experimentellt fastställdarangordningen.
InDeGrainS I
49
Palmquist, Jens-Petter. "Carbide and MAX-Phase Engineering by Thin Film Synthesis." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3972.
Full text
50
Drahokoupil, Petr. "Výzkum záporných elektrod pro lithno-iontové akumulátory." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220105.
Full textAbstract:
This thesis deals with lithiation of negative electrode li-ion batteries. In this thesis is used several electrode materials: carbon, FeCl3, lithiated carbon electrodes and silicon carbide. Reduction of irreversible capacity lithium-ion batteries leads to increased capacity and also we can use new materials as a positive electrode. Thesis deals with the differences in the properties of materials using lithiation and their use in practice