Dissertations / Theses on the topic 'Corrosion et anticorrosifs'
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 'Corrosion et anticorrosifs.'
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.
Reffass, Mohammed. "La corrosion localisée des aciers en milieu NaHCO3/NaCl et son inhibition par les ions HPO42 et NO2 : rôle des composés à base de Fe(II)." La Rochelle, 2006. http://www.theses.fr/2006LAROS164.
Full textThe aim of this work is to understand the pitting mechanisms of S235 carbon steel in aerated aqueous NaHCO3/NaCl solutions and to study the effect of two inhibitors (HPO42- and NO2-) on pitting of steel in the same media. Electrochemical measurements coupled to spectroscopic analysis were used to characterize pitting corrosion. The activity of a given pit has been studied by scanning Vibrating Electrode Technique (SVET). The micro Raman spectroscopy is used to identify and to follow, in situ, the evolution of the corrosion products formed in the pits. In parallel, a chemical study of synthesis and oxidation of the products likely to form in the pit has been done in experimental conditions similar to those found in the pits. The characterization, in situ, of the products of corrosion formed in the pits showed that the first corrosion product formed is an iron carbonate FeCO3 named siderite. The oxidizing action of the dissolved oxygen present in solution, transforms siderite into carbonated green rust, that is then oxidized into goethite. These results seem to show that a meaningful relation exists between the nature of the corrosion products and the process of development of the pits. Indeed, the formation of siderite and green rust signs a fast development of the pit, whereas the formation of ferric compounds is associated to a slowing of the development of the pit and an acceleration of their repassivation. The same methodology has been used for the study of the effect of two corrosion inhibitors (HPO42- and NO2-) on the process of pitting of the studied steel. The inhibition by the HPO42- ions is explained by a reduction of the proportion of siderite formed to the profit of an iron phosphate (vivianite), product known to be rather protective. For elevated concentrations of HPO42-, the exclusive formation of the vivianite gives a better protection against pitting. For the NO2- ion, the inhibiting effect seems to come from the formation of Fe(III) complexes [Fe(H2O)6]3+. Indeed, the characterization of the corrosion products formed in the pits in presence of the nitrite ions gave the complex [Fe(H2O)6]3+ with a weak proportion of siderite. NO2- ions oxidize quickly the dissolved Fe(II), giving a Fe(III) complex probably precursors of the Fe(III) spinel oxides of the passive film
Bentiss, Fouad. "Synthèses et études physicochimiques des inhibiteurs organiques de corrosion en milieu acide." Lille 1, 1999. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1999/50376-1999-237.pdf.
Full textMonget, Julie. "Elaboration et caractérisation de revêtements fonctionnels hybrides pour l’aéronautique." Paris 6, 2010. http://www.theses.fr/2010PA066731.
Full textBommersbach, Pascale Dumont-Alemany Catherine Millet Jean-Pierre. "Evolution des propriétés d'un film inhibiteur de corrosion sous l'influence de la température et des conditions hydrodynamiques caractérisation par techniques électrochimiques /." Villeurbanne : Doc'INSA, 2005. http://docinsa.insa-lyon.fr/these/pont.php?id=bommersbach.
Full textVaugelade, Stéphane. "Développement et mise au point d'une banque de données sur les revêtements et la corrosion à haute température." Aix-Marseille 3, 1995. http://www.theses.fr/1995AIX30003.
Full textLebrini, Mounim Lagrenée Michel. "Synthèses et études physicochimiques de nouveaux thiadiazoles inhibiteurs de corrosion de l'acier en milieu acide." Villeneuve d'Ascq : Université des sciences et technologies de Lille, 2007. https://iris.univ-lille1.fr/dspace/handle/1908/178.
Full textN° d'ordre (Lille 1) : 3659. Résumé en français et en anglais. Titre provenant de la page de titre du document numérisé. Bibliogr. à la suite de chaque chapitre. Liste des publications et communications.
Barchiche, Chems-Eddine. "Caractérisation et cinétique de formation des dépots calcomagnésiens sur acier en eau de mer artificielle." La Rochelle, 2004. http://www.theses.fr/2004LAROS111.
Full textCathodic protection is commonly used to prevent the corrosion of carbon steels in seawater. This method consists in decreasing the potential of metal so that its corrosion kinetics becomes negligible. It can be achieved via two different procedures. The first one consists in using a generator to provide a sufficiently cathodic current, the second one consists in coupling the metal with so called sacrificial anodes made of a less noble alloy. Cathodic protection promotes oxygen reduction on the metal surface, that is production of OH- ions, increase of the interfacial pH and finally the formation of a mineral deposit. This isolating layer hinders the diffusion of dissolved O2 and therefore decreases the current required for protection. A better understanding of the physico-chemical properties of these deposits should permit to optimise the protection, decrease the energetic need or the sacrificial anodes dissolution. The experiments described here were performed using steel electrodes in artificial seawater. This allowed us to vary an important number of parameters, in particular the composition of the electrolyte. The deposition of Ca compounds and that of Mg compounds were studied separately before the investigation of the simultaneous deposition of Ca and Mg compounds. Chronoamperommetry and electrochemical impedance spectroscopy were used to study the kinetics of formation of the deposits. Scanning electron microscopy, Raman spectroscopy, X-ray diffraction and atomic force microscopy were used to characterise the deposits
Bentiss, Fouad Lagrenée Michel. "Hétérocycles pentaatomiques synthèses organiques, études des propriétés inhibitrices de la corrosion et des propriétés complexantes /." Villeneuve d'Ascq : Université des sciences et technologies de Lille, 2007. https://iris.univ-lille1.fr/dspace/handle/1908/985.
Full textN° d'ordre (Lille 1) : 522. Résumé. Titre provenant de la page de titre du document numérisé. Bibliogr. à la fin de chaque chapitre.
Lebrini, Mounim. "Synthèses et études physicochimiques de nouveaux thiadiazoles inhibiteurs de corrosion de l'acier en milieu acide." Lille 1, 2005. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2005/50376-2005-Lebrini.pdf.
Full textBommersbach, Pascale. "Evolution des propriétés d'un film inhibiteur de corrosion sous l'influence de la température et des conditions hydrodynamiques : caractérisation par techniques électrochimiques." Lyon, INSA, 2005. http://theses.insa-lyon.fr/publication/2005ISAL0060/these.pdf.
Full textThis work deals with the electrochemical study of a corrosion inhibitor intended to protect steel pieces, mainly used in the mechanical machining industry. The general characterization of the inhibitor, carried out essentially by electrochemical impedance spectroscopy revealed that the latter acts anodically by forming, at the material surface, a three-dimensional layer integrating first corrosion products. Mechanism of degradation, observed in particular when inhibitor is added in non sufficient quantity, was then highlighted and attributed to a film water-uptake. Finally, the influence of physical parameters related to the operating conditions (temperature and hydrodynamic conditions) showed that these two parameters are responsible for an important evolution of the film, particularly on its chemical composition and morphology
Cambon, Jean-Baptiste. "Élaboration et caractérisation de revêtements anti-corrosion par voie sol-gel sur l'acier inoxydable martensitique X13VD." Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1892/.
Full textThe thesis focuses on the development and characterization of sol-gel coatings on X13VD martensitic steel. The first experimental part was used to evaluate the corrosion behavior of X13VD stainless steel, a study undertaken on the effectiveness of corrosion inhibitors: Ce(NO3)3 and Na2MoO4 selected according to the literature. The performances of two types of hybrid coatings prepared from two formulations of sol, " methacrylate-based " and "epoxy-based", were also compared. The second part focuses on the study of the chemical structure by nuclear magnetic resonance spectroscopy (NMR 13C, 29Si, 27Al) of the hybrid "epoxy base" formulation, the most interesting system for corrosion protection of X13VD stainless steel. This investigation enables to understand the influence of inhibitors incorporation in the hybrid matrix and also of heat treatment, on the reaction mechanisms leading to the formation of the sol-gel network. The last part of this work concerns the mechanical and electrochemical characterization of different hybrid "epoxy base" coatings deposited on steel X13VD differing in the nature and content of corrosion inhibitor and heat treatment. Correlations are proposed with previous results demonstrating the interdependence between the performance of hybrid coatings and their chemical structures investigated by NMR spectroscopy
Outirite, Moha. "Synthèse et étude des propriétés complexantes et inhibitrices de corrosion des oxadiazoles et des pyrazoles substitués par des groupements potentiellement chélatants." Thesis, Lille 1, 2008. http://www.theses.fr/2008LIL10080/document.
Full textThe aim of this work is the synthesis of new families of inhibitory of corrosion molecules of metals, in particular of steel, and the assessment of their inhibitory power. Some of these molecules being potentially chelatants, the synthesis and the structural survey of new complexes of coordination have been achieved. The originality of work resides in the preoccupation to synthesize products deprived of toxicity by original methods of synthesis making notably calI to the techniques of irradiation by microwave. The used organic molecules are heterocyclic compounds substituted by aromatic groupings rich in electrons or by groupings carbonyls comfortably transformable in chelatants functions (oximes, imines ... ) and capable to drive to macrocycles. The simple procedures of synthesis, permit to obtain these products with excellent outputs has been finalized. The measures of efficiency of these molecules as inhibitors of corrosion are done by Electrochemical impedance Spectroscopy. ln every case, the influence of substituting was studied, for example, for the grouping pyridyl, the position of the nitrogen atom is discussed. Besides the inhibitory properties of corrosion, Sorne derivatives of these nitrogenous molecules to five linkages as the oxadiazoles and pyrazoles present the advantage to be potentially ligands chelatants and permit to get the complex mono, bi and polymétallic. Interactions between metals carriers of spin can take lace through the intermediary of these Iigands collectors
Phan, Thi Trang. "Elaboration et caractérisation électrochimique de revêtements sol−gel hybrides pour la protection d’un acier au carbone contre la corrosion." Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10104/document.
Full textThis thesis is realized within the framework of the FUI project INNOVAXLES in collaboration with MG-VALDUNES company. The objective of the project consists in developing efficient coatings for corrosion protection of new railway axles to extend their lifetime. In this context, a sol-gel process allowing to obtain hybrid coatings from 3−trimethoxysilyl propyl methacrylate (MEMO) and bis−[2−(methacryloyloxy) ethyle] phosphate (BMEP) on carbon steel with high resistance to corrosion is developed. At first, the optimization of several experimental parameters such as hydrolysis time, drying temperature, drying duration, sol dilution in ethanol, molar ratio between precursors, drying conditions and acid catalysts nature is realized in order to obtain a coating showing the best anticorrosion properties. The effect of these parameters on the microstructure and anticorrosion performance of the hybrid sol−gel coating is investigated using different characterization methods (FTIR, solid NMR, XPS, SEM, potentiodynamic polarization, EIS,..). The second part of the study concerns the development of surface pretreatment processes of the steel by phosphatation, the incorporation of nanoparticles of iron oxide Fe3O4 as well as Ce(NO3) as an inhibitor of corrosion in the hybrid sol in order to improve the adhesion and the corrosion resistance performance. An optimized coating presenting good adhesion and very stable anticorrosion properties during immersion in 3wt% NaCl and showing a high value of impedance modulus at low frequency (107 Ω.cm2 after 1248h of immersion) is obtained
Hollner, Stéphanie. "Développement de nouveaux traitements de protection à base d'acide carboxylique pour la conservation d'objets en fer du patrimoine culturel." Thesis, Nancy 1, 2009. http://www.theses.fr/2009NAN10062/document.
Full textWithout any protection treatment, lots of artefacts or elements from our cultural heritage slowly decay because of atmospheric corrosion. Therefore there is a need for temporary, cheap, easy-to-use and non-toxic protection systems, fitting to the actual environmental laws. These treatments could give new solutions to the conservators for protecting the artefacts and sometimes avoid them complex and expensive restoration works. Long chain carboxylic acids have been chosen for this purpose, and used in different kinds of treatments. Their good performances are proved by electrochemical measurements and artificial and natural ageing tests. In parallel with this work, the iron (III) carboxylate, which is the compound responsible for the inhibition properties, has been studied in term of morphology, structure, and chemical properties, thanks to many analytical techniques. This work finally leads to propose a specific and adapted solution for each element or artefact that has to be treated- depending on its surface, its environmental conditions of exposure, the emergency of its treatment, and the financial and human means available
Chevalier, Maxime. "Étude de l'effet des alcaloïdes de deux espèces d'arbres guyanaises (Xylopia) sur la corrosion de l'acier C38 en milieu hydrochlorydrique 1M : études électrochimiques et phytochimiques." Thesis, Antilles, 2015. http://www.theses.fr/2015ANTI0099.
Full textToday, the research and development of ecofriendly biosourced inhibitor have gained a great interest. The laboratory L3MA is involved in the research and characterization of alkaloids isolated from plants growing wild in Guyana as corrosion inhibitor.The present work continues to focus on the broadening application of plant extracts for metallic corrosion control and reports on the inhibiting effect of alkaloidic extract from two plants: Xylopia frutescens and Xylopia cayennensis. The molecules used are considered like ecofriendly and can be used as corrosion inhibitor of C38 steel. More than 90% of efficiency was obtained. The same workflow was used for each plant: firstly the study of the total alkaloidic extract with polarization curves and electrochemical impedance spectroscopy. In second time, the alkaloidic extract is chromatographied and the main composants are isolated and identified. These main components are tested as corrosion inhibitor, to determine the mode of action and the adsorptions’ forms. XPS and SEM studies confirmed that the plants alkaloidics extracts and the main composants are strongly adsorbed onto the steel surface
Bouali, Imane. "Étude d'inhibiteurs de corrosion métallique à base d'orthophosphates de zirconium lamellaires fonctionnalisés : synthèse, caractérisations et applications." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0118/document.
Full textThis thesis generally aims at the development of corrosion inhibitors based on a lamellar compound, namely zirconium orthophosphate (α-ZrP). The principle consists in that α-ZrP acts as micro-tanks in such a way to store species of several compounds known for their metallic corrosion inhibition properties. On the other hand, inhibitive species based on Ca2+, Mg2+, and Zn2+ were be able to be successfully incorporated within α-ZrP interlayer spaces via cationic exchange with labile H+ protons. Similarly, entities of the heptanoate anion were inserted via the prior intercalation of the cationic biopolymer chitosan. Nevertheless, the intercalation of organic species such as 2-aminobenzimidazole, dodecylamine was accomplished via acid-basic reaction between –NH2 groups and H+ protons. The characterizations of the materials before and after functionalization by different analytical techniques denote that all these modifications give rise to inorgano-inorganic or organo-inorganic hybrid materials. The evaluation of their performances, in term of metallic corrosion inhibition, was performed by using stationary or dynamic electrochemical techniques. It has been shown that the use of these pigments in corrosive medium, either alone or dispersed in paints, improves corrosion inhibition of zinc and mild steel thanks to the progressive release of intercalated species compensated by the retention of corrosive entities better than those induced by commercial products. This in final allows lengthening the inhibition action of metallic substrates against aqueous corrosion
Bin, Hussin Mohd Hazwan. "Extraction, modification and characterization of lignin from oil palm fronds as corrosion inhibitors for mild steel in acidic solution." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0135/document.
Full textLignocellulosic biomass in Malaysia can be considered as one of the promising sources of renewable energy. It is mainly composed of cellulose, hemicellulose, and lignin and best-suited for energy and chemical applications due to its sufficient availability, inexpensive and is sustainable. In general, the production of lignocellulosic biomass in Malaysia was considered high and mainly derived from the palm oil industries (approximately 60 million tonnes of oil palm waste were generated in a year). The oil palm biomass waste could possibly be used as alternative resources for the production of paper and cardboard. However, massive amounts of lignin by-product could also be discarded in huge quantities (by the pulp and paper industry) due to lack of awareness on its potential. Having high content of diverse functional groups (phenolic and aliphatic –OH, carbonyls, carboxyls, etc.) and phenylpropanoid structure, lignin can lead to substitutes in industrial applications such as in corrosion inhibition of metals and alloys. Since the oil palm fronds (OPF) are one of the largest biomass waste contributors in Malaysia, it was therefore used as raw material in this study. In order to improve the lignin extractability and properties, the extraction was conducted in different ways (via direct delignification and/or combined pretreatment methods). Due to the high hydrophobicity of lignin, it limits the capability to act as efficient corrosion inhibitors. Hence, modifications of the OPF lignin structure were conducted in two ways; (1) by incorporating organic scavengers (2-naphthol and 1,8-dihydroxyanthraquinone) during autohydrolysis pretreatment before organosolv treatment (percentage yield of lignin: AHN EOL = 13.42±0.71 % and AHD EOL = 9.64±0.84 %) and (2) fractionation of lignin from direct delignification processes (Kraft, soda and organosolv) via ultrafiltration membrane technique (percentage yield of permeate lignin fractions: Kraft = 5.41±2.04 %; soda = 12.29±0.54 % and organosolv = 1.48±0.15 %). The physical and chemical properties of the modified lignins were evaluated by using Fourier Transform Infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC), thermal analysis and high performance liquid chromatography (HPLC). Modified lignin fractions with higher phenolic –OH content but lower molecular weight, polydispersity as well as aliphatic –OH content resulted in higher values of antioxidant activities. The antioxidant activity seems be dependent on the increase of their free phenolic –OH and ortho-methoxyl content, through the stability of the radical formed and the ability to reduce Fe3+ ions to Fe2+ ions. Indeed, the improved physicochemical properties and antioxidant activity of modified lignin gave positive correlation with the mild steel corrosion inhibition action in 0.5 M HCl solution that were evaluated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss measurements. The best percentage of inhibition efficiencies (IE: 81 – 90 %) were attained at the concentration of 500 ppm for all lignin inhibitors but decreased with the increase in temperature (303 – 333 K). Thermodynamic data indicated that the adsorption of the modified lignin onto the mild steel was spontaneous and the inhibitors were mainly physically adsorbed (physiosorption), supported by the activation energy of adsorption, Ea. The enhanced protective properties of the modified lignin will pave way for an alternative approach for the utilization of these natural waste materials
El, Alaoui Sidi Mohammed. "Elaboration et étude des revêtements réfractaires sur un acier inoxydable austenitique Fe-Ni-Cr." Toulouse 3, 2005. http://www.theses.fr/2005TOU30095.
Full textThe rise in temperature of operation of the heat engines and in particular of the engines (combustion chambers, aeronautical turbines of engines. . . ) makes it possible to increase their output for energy saving. The major problem of operation at high temperature is that of the behaviour to oxidation of metals and alloys. The use of thermal refractory material barrier and diffusion barriers made up makes it possible to mitigate this problem. The effectiveness of these barriers depends on their formulation which is related to their conditions of manufacture. This work falls under the development of ceramic coatings (alumina) worked out by soft chemicals to protect the refractory stainless steels and super alloys against oxidation at very high temperature. These coatings are obtained by chemical way, on a substrate functionalized beforehand by a treatment of conversion. The results presented relate to an alumina coating on austenitic stainless steel substrate. A first stage consisted in optimizing the treatment of conversion and in particular the formulation of the bath to functionalize the substrate. The layers of conversion obtained are nanostructurées and present a character fractal. In a second stage, the use of the Experimental design methodology (M. R. E), us made it possible to optimize the properties of the alumina deposit; it is about a deposit induced by electrolysis and particularly member. Two significant parameters were studied: the time and density of current. These deposits characterized by spectroscopie of mass of the secondary ions (SIMS) and Diffraction of the X-ray reveal gradients of concentration in radiant what explains good resistance to chipping. The tests thermogravimetric showed a very significant improvement of the behaviour to oxidation at high temperature of steel
Constantin, Florina. "Etude de l’efficacité d’inhibiteurs de corrosion utilisés dans les liquides de refroidissement." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0117/document.
Full textFor motorization, problems related to the compatibility ‘materials cooling liquids’ are complex because of their nature and function. They can be solved either by changing the shape of some parts of engine in order to obtain a better flow, or by introduction of effective corrosion inhibitors. And these later that are very used in the automotive industry, must be always optimized and adapted to the evolution of the materials. Today, the demands connected with carburant consummation and environment lead more and more operators to opt for aluminum and its alloys. In this work, we have characterized the corrosion behavior of Al-Mn alloy and of a new material, namely ''sandwich material'' consisting in a core of Al-Mn alloy veneered on both sides by a thin layer of Al-Si alloy and therefore with a structure Al-Si/Al-Mn/Al-Si in contact with commercially coolant, namely Glaceol D. The later one contains in its composition tolytriazole, as a corrosion inhibitor. This study of behavioral characterization of these materials was carried on using conventional stationary electrochemical techniques as the open circuit potential measurements, the potentiodynamic recordings, the determination of polarization resistance, coupled with metallographic observations. The main parameters considered were the influence of a pretreatment of metal surface and physic–chemical conditions of environmental study as the content of active compounds (by choosing the dilution of Glaceol D, the content of inhibitor is fixed), the nature of the dilution water (deionized or added of NaCl) and temperature: this latter one was chosen either stationary (between room temperature and 80°C) or as a thermal cycling. On the other hand, and that has allowed to establish the better behavior of the sandwich material, we tested the 99.99% pure aluminum, in the same conditions of concentration and temperature. In addition to this traditional and industrially used inhibitor, which is in the composition of the commercial product recommended by the French – Romanian company “Dacia-Renault”, we tried a new original approach by testing the effectiveness of a “green inhibitor” - a plant extract: Allium Sativum (or garlic), where the main active ingredient is allicine. By its functional group type thiosulfinate RS(= O)-SR, and the sulfur and oxygen atoms with non-binding electronic doublets, this compound has the characteristics of a film-forming product and can be put into the category of new types of “green” inhibitors investigated during the last few years
M'Hiri, Nouha. "Étude comparative de l’effet des méthodes d’extraction sur les phénols et l’activité antioxydante des extraits des écorces de l’orange « Maltaise demi sanguine» et exploration de l’effet inhibiteur de la corrosion de l’acier au carbone." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0183/document.
Full textThis work is a contribution to the valorization of “Maltease peel”. The objectives of this research are (i) to study the efficiency of different extraction methods in terms of total phenol contents (TPC), total flavonoid contents (TFC), individual flavonoids (FI) and antioxidant activity of extracts and (ii) to examine the corrosion inhibition of carbon steel in acidic and basic medium by orange peel extract and its main antioxidant compounds. For this, five extraction methods were used: conventional solvent extraction, CSE (ethanol (80%), m/v: 5g:50ml, 30 min, 35°C, mechanical stirring in the dark and 3 successive extractions), microwave assisted extraction, MAE (ethanol (80%), m/v: 5g:50ml, 3 successive extractions, and 180s, 67-108°C, 100-400W or at 35°C), ultrasound-assisted extraction, UAE (ethanol (80%), m/v: 5g:50ml, 30 min, 35°C, 100-200W and 3 successive extraction), high-pressure extraction, HPE (ethanol (80%), m/v: 5g:50ml, 30 min, 35°C, 0,1-100 MPa and one extraction) and supercritical CO2 extraction, SC-CO2 (ethanol (80%), m/v: 5g:50ml, 30 min, 35-80°C/10-22 MPa and 3 successive extractions). This byproduct is rich in functional ingredients such as total phenols (1.96 ±0.002 g GAE/100g DM) and vitamin C (0.10±0.003 g/100g DM). Ten individual flavonoids (FI) were identified in the extract of Maltease orange peel. Neohesperidin (0.860±0.003 g/100g orange peel powder) and hesperidin (0.551±0.001 g/100g orange peel powder) are the major compounds. The operating conditions of extraction that have achieved the highest levels of total phenol and flavonoid contents are 200 W, 76°C during 180s for MAE; 125 W during 30 min at 35°C for UAE; 80°C and 10 MPa for SC-CO2 extraction and 50 MPa,35°C during 30 min for HPE. The comparison of the different extraction methods performed at the same operating conditions (m/v: 5g/50ml, 80% ethanol, 35°C, 3 successive extractions) shows that the MAE has the highest levels of TPC and TFC, followed by UAE, CSE, HPE and SC-CO2 extraction, as well as the major individual flavonoids. However, results concerning antioxidant activity cannot be correlated to TPC, TFC or individual flavonoids and it differs depending on the test used. Orange peel extracted by HPE presents higher radical scavenging capacity compared to extracts obtained by other extraction methods. Moreover, it can be noticed a significant decrease of the antioxidant activity measured by the ABTS method in the following order: HPE, CSE, SC-CO2, MAE, UAE, whereas, it is EHP, ECS, EAM, EAU, SC-CO2 extraction for DPPH test. The study of the anti-corrosion effect of the orange extract and its antioxidant compounds (neohesperidin, naringin and ascorbic acid) showed a significant inhibition effectiveness of the corrosion steel with orange peel extract (95%) relative to that of its antioxidant compounds: ascorbic acid (92%), neohesperidin (87%) and naringin (56%). The anti-corrosion efficiency of orange peel extract is not only due to the antioxidant activity of identified compounds, but probably also to a synergic effect of molecules and to the formation of a three-dimensional surface of the film. This film can be formed due to the presence of other compounds in the extract such as pectin
Leroy, Pierre. "Calcium et corrosion." Paris 5, 1991. http://www.theses.fr/1991PA05P623.
Full textKharmachi, Imen. "Elaboration électrochimique des revêtements composites Ni-Co sur l'acier au carbone et étude des propriétés physico-chimique et anticorrosives." Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2072.
Full textIn this work, the elaboration of Ni-Co coatings by pulse and continuous electroplating oncarbon steel substrate from a supporting electrolyte with low nickel content can produce betterphysicochemical and anticorrosive properties as well as reduce the toxicity of the plating bath.A Doehlert plan was exploited to optimize the various plating parameters. On the one hand,the addition of additives (hydroquinone, gelatin and TiO2 nanoparticles) in the electrolyte hasa remarkable effect on the physical and chemical properties of the deposits (morphology,content of cobalt in the coating and micro hardness…). Composites and nanocompositesalloys are more compact, less porous with finer texture and good adhesion than the base Ni-Co coating without addition of additives. On the other hand, these deposits have a betterprotection against corrosion and a good stability in aggressive media 3% NaCl
Aouadi, Khalil. "Développement d’une nouvelle génération de revêtements ultra-durs. Etude de leur comportement tribologique et anticorrosif." Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0041/document.
Full textThe aim of this study was to develop and characterize a new generation of wear and corrosion resistant multilayers Cr-N based coatings. Due to the severe conditions that wood cutting tools are subjected in addition to the environmental issue associated with the use of cutting fluids during wood machining, the monolayers that constitute our multilayers system must have specific characteristics. As a result, thin layers of Cr, CrN and CrAlN have been deposited on wood cutting tools steel and silicon substrates by DC reactive magnetron sputtering to be optimized. Then, the optimal monolayerscoatings were combined to develop the Cr/CrN/CrAlN multilayers. that were characterized to determine their physicochemical, mechanical, tribological properties and their corrosion behavior. The results obtained indicated that the application of a multilayer coating can greatly improve the wear and corrosion resistance of a wood cutting tools steel
Guessoum, Khadoudj. "Nouveaux alliages zinc-terres rares pour des applications anticorrosion : élaboration, propriétés et traitements de surfaces." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0071/document.
Full textNew Zn-RE1-5 wt.% alloys (RE=Ce, La and Mischmetal: Ce 75%/ La 25%) were synthesized by melting under controlled atmosphere and cast in plates. In these materials, rare earth metal are exclusively present in intermetallic phases homogeneously dispersed in the zinc matrix: Zn11Ce, Zn13La or Zn11Ce1-xLax and Zn13CeyLa1-y. The electrochemical behavior of these new alloys was investigated in a reference corrosivemedium. In parallel, the pure intermetallic phases Zn11Ce and Zn13La were synthesized and their electrochemical influence was studied by voltametry and galvanic coupling. Results show that both intermetallic phases act as preferential cathodic sites of dioxygen reduction and induce a cathodic inhibition of the corrosion of the Zn-RE alloys by comparison with pure zinc. This phenomenon is much more significant in the case of lanthanum containing alloys. In the specific case of cerium addition to zinc, an anodic inhibition was also observed and correlated with a chemical modification of the corrosion products (mainly made of hydrozincite). Actually, low quantities of cerium (less than 1 at.%) have been detected homogeneously in the corrosion layer by wave-length dispersive spectrometry. From results of controlled precipitation experiments of cerium and zinc salts performed in carbonated medium, the presence of cerium in the corrosionlayer and its protective character could be attributed to the formation of a mixed double lamellar zinc-cerium product. Therefore, addition to zinc of less than 2 wt.% of cerium or lanthanum allow to improve the corrosion resistance of zinc. However, by increasing the rare earth content in the alloys, the galvanic coupling phenomenon becomes more important and makes the alloys less resistant than pure zinc
Gavrila, Marlène. "Caractérisation microstructurale et électrochimique de revêtements Zn-Ni électrodéposés sur un acier, en vue d'applications anticorrosion." Lyon, INSA, 1996. http://www.theses.fr/1996ISAL0028.
Full textThe use of cadmium as an anti-corrosion coating is now regulated because of its toxicity. Among the possible replacements the electrolytic deposit of alloyed zinc, in particular zinc-nickel, has given rise to several studies; The objective of this study is to better understands the relationships between the characteristics of the deposits (composition, structure, morphology, porosity …) and their anticorrosion performance. Different coatings were tested and the following conditions noted: nature of bath (acid or alkaline), density of the electrodepositing current, eventual post treatments of degasification or chromatation. For comparison the classic deposits of cadmium or pur zinc were also characterized. The morphological and structural characteristics were determined by X-diffraction, microscopy (MO or MEB) and the internal-stresses were also determined. The corrosion resistance was studied in a neutral aerated saline solution at room temperature by stationnary and non-stationnary electrochemical techniques. The alkaline deposits of nickel composition varying from 6 to 10 % in weight according to the conditions of preparation are porouse, and little altered by degasification. Impedance tests prove this porosity. Long duration immersion in a corrosive solution causes the appearance of an important of net craquelures; the acidic deposits richer in nickel (10 to 20 % in weight) are sensitive to the density of the electrodepositing current, so there is a risk of a difference in concentration and therefore a galvanic couple. The degasification causes the appearance of cracks. In general, corrosion processus is a dezincification of the deposits. A treatment of chromatation detectable by impedance spectroscopy always improve the corrosion resistance
Astruc, Alexandre. "Microstructure et perméabilité de revêtements anticorrosion : influence des contraintes hygrothermiques et rôle des interphases." Toulon, 2007. http://www.theses.fr/2007TOUL0008.
Full textThe aim of this work is, firstly, to improve coatings microstructure description and to study their permeabilin. The second aim is to search expérimental protocols to evaluate thèse propertîes along accelerated aging. A modei coaring and an anticorrosion primer are studied. Both are based on thé same polymer bînder DGKBA-Polyamidoamide, Filkr and pigment influence on coating microstructure hâve been evidenced by différent characterisation methods. For weak CPV values, thé présence of interphases was shown. One conséquence is thé àecrease of thé crosslink density and thé fraction of free volume. The hydrophilic group concentration and thé CPV mainly control thé binder polymer permeability, and ils degree of plasticization. Moreover, thé degree of permeability and thé thickness directly influence thé barrier properties characterized by thé évolution of thé rvres résistance Rp. Hygrothermal stresses induce a faster decreasc of thé barrier and adhésion properties than •J-. E one due to only thermal stresses. This évolution was attributed to thé cycling of drying and water absorption phases, and then to délamination. The growing of filler/matrix interface number also promîtes thé détérioration of thé barrier properties. However. Adhésion, evalualed by pull off test is less affected by relative humidiry and température variations when filler and pigment are add to thé organic coating. On thé base of thèse resulis. Some criteria may be used to evaluate thé performance or thé durability of a coating. We can adopl those are lînked to i~e degree of permeability (Rp, tp). Thé degree of plasticization and thé clusteringof water molécules at thé métal interface (Tg,/. ,)
Dallies-Labourdette, Eric. "Formation et caractérisation de dépôts de silice sur fibres de carbone : rôle de l'interface dans la protection des fibres contre l'oxydation." Mulhouse, 1990. http://www.theses.fr/1990MULH0138.
Full textGrari, Olfa. "Amélioration des propriétés physico-chimiques et anticorrosives du revêtement de polypyrrole électrodéposé sur l'acier inoxydable 304." Thesis, Besançon, 2015. http://www.theses.fr/2015BESA2041/document.
Full textThe aim of this work is to electrochemically elaborate polypyrrole films on 304 stainless steel in phosphoric acid solution and improve corrosion resistance by the use of high frequency ultrasound (US), incorporation of inorganic inhibitor (KNO3) and silica (SiO2) particles. The inorganic inhibitor reduced the oxidation potential of pyrrole monomers and was incorporated into polymer matrix. Ultrasound favors electrochemical polymerization reaction by improving mass transfer towards the electrode. It leads to films more compact, presenting a thinner and more homogeneous topography. PPy-SiO2 composite films were prepared by different methods. Good particles distribution within polymer matrix was achieved through multilayered method. All formed films: PPy-NO3-, PPy-US and PPy-SiO2 offer better protection of stainless steel against corrosion in chloride environment than PPy coatings
Schiff, Nicolas. "Influence des fluorures sur la résistance à la corrosion des alliages de titane et des alliages non précieux utilisés en odontolgie." Lyon 1, 2005. http://www.theses.fr/2005LYO10201.
Full textJeanmaire, Thomas. "Synthèse et polymérisation de méthacrylates phosphones. Application à l'anticorrosion." Montpellier 2, 2002. http://www.theses.fr/2002MON20042.
Full textDupont, Caroline. "Propriétés anticorrosives du chitosane et du N-(2-carboxylate)benzoylchitosane de sodium pour la protection du fer." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25155/25155.pdf.
Full textBoulares, Asma. "Élaboration électrochimique des films composites à base d’oxyhydroxyde de titane et d’oxyde de manganèse TiO(OH)2/MnO2 sur le cuivre. : Caractérisation, propriétés et application anticorrosion en milieu chloruré." Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCD038.
Full textCopper and its alloys are frequently used in heating and cooling plants as well as in electrical and mechanical systems. Despite its semi-noble character, copper undergoes severe corrosion in urban, industrial or marine environments. The use of metallic and polymeric coatings has revealed considerable efficacy against copper corrosion. However, metal oxides and oxyhydroxides coatings haven't yet been used due to their powdery appearance and delicate synthesis.The objective of this work is to electrochemically elaborate composite films based on titanium oxyhydroxide and manganese oxide on an oxidizable copper substrate and to evaluate their effectiveness against corrosion in chloride medium.TiO(OH)2/MnO2 composite film presents minimum protection against copper corrosion in chloride medium. Hence the necessity to adopt other alternatives to improve its performances.The use of polyethylene glycol PEG12000 and the change of the solvent nature allows the elaboration of TiO(OH)2/MnO2/PEG12000 and TiO(OH)2(SM)/MnO2(SA) composites with attractive physicochemical and anticorrosive properties. This improvement over the reference composite TiO(OH)2/MnO2 is attributed to the formation of PEG-CuCl and TiO(OH)2(SM)/ MnOOH barrier layers, respectively, which prevent the penetration of chloride ions on the copper surface, thus minimizing pitting corrosion
Villareal, Laura. "Couplage des analyses calorimétrique, gravimétrique et électrochimique pour l'étude de l'effet barrière de peintures anticorrosion." Thesis, Toulouse, INPT, 2020. http://www.theses.fr/2020INPT0053.
Full textThe aim of the thesis was, first, to characterize the performances of commercial high-solids epoxybased coating for the corrosion protection of steel structures in immersion, in order to further improve the level of protection of a water-based coating in development at Peintures Maestria. This work was based on the coupling of different techniques, namely the electrochemical impedance spectroscopy (EIS) and the physicochemical analysis of polymers. The notion of barrier effect was questioned all along the thesis. First, the water uptake of the high-solids coating was studied from the impedance data as a function of the immersion time in a 0.5 M NaCl solution and with gravimetric measurements on free-standing films. The water fraction values obtained from the two methods were in acceptable agreement. The gravimetric measurements indicated a mass loss attributed to a release of a plasticizer from the formulation. This compound was dosed in the NaCl solution. The use of the dielectric permittivity formalism allowed the impedance data to be analysed from the molecular mobility standpoint. Mean relaxation times associated with the dielectric manifestation of the glass transition (in other words, markers of the molecular mobility) were obtained from EIS data. A very good agreement was found between the evolutions of: (i) the glass transition temperature (determined from differential scanning calorimetry on free-standing films), (ii) the mean relaxation times and (iii) the dc conductivity values, with respect to immersion time in the NaCl solution. This led to the conclusion that the water uptake and plasticizer leaching processes significantly influence the physical structure which, in these epoxy systems, governs the barrier properties. Then, the film formation of the water-based coating was characterized at different levels of formulation (epoxy/polyamidoamine model, varnish and completely formulated system). Optical microscopy observations and FT-IR analysis showed that the coalescence of the resin particles, which allows the formation of a homogenous film, was a critical step linked to both the molecular mobility and the curing process. Despite the incomplete film formation, the developed water-based coating presented satisfactory performances in terms of barrier properties and adhesion
Pouteau, Dominique. "Elaboration et caractérisation de revêtements réalisés en OMLPCVD améliorant la résistance à la corrosion et à l'usure des alliages de magnésium." Toulouse, INPT, 1990. http://www.theses.fr/1990INPT038G.
Full textQuach, Thi Hai Yen. "Etude de la durabilité d'un primaire epoxy anticorrosion : rôle de l'interphase polymère/métal et conséquence sur l'adhérence." Toulon, 2010. https://theses.hal.science/tel-00647580/fr/.
Full textThe organic coatings durability is an important industrial and scientific topic. The life time of an anticorrosion coating depends mainly on its adhesion on the metallic substrate. The aim of this work consists in indentifying the interphase area and understanding its influence on adhesion between an anticorrosion coating and a metallic substrate. We try also to validate experimental parameters for following coating deterioration, as well as the development of corrosion or delamination at the metallic interface during immersion. These protocols may be use to predict the coatings durability. A no filled coating with different stoichiometries and a commercial primer are studied. Both are based on the same polymer binder DGEBA-Polyamidoamide. The anticorrosion coating is formulated with a vinyl terpolymer, ferrous oxide and zinc phosphate as anticorrosion pigments and talc as main filler. Different methods are used to characterize the interphase area in the DGEBA / Polyamidoamine systems applied onto steel: the Fourier Transformed Infra Red spectroscopy (FTIR), the Micro Thermal Analysis (µTA) and a method based on deflexion measurements. We have observed differences of behaviour between the properties of the interphase and those of the bulk one. The inherent limits of the characterization by deflexion measurements drive to overestimate the thickness of the interphase. The characterizations by IR and µTA have allowed observing the interphase to a smaller scale. We have then observed by IR a strong presence of amine in an interphase are a which thickness is about 40 µm. This strong concentration of amine is also confirmed by µTA results, that drive to a reduction of Tg from the bulk to the metallic interface. Different samples have suffered a hygrothermal artificial ageing test, which involved modifications of the interphase. Moreover, a study by Electrochemical Impedance Spectroscopy (EIS) is performed in order to characterize evolutions of protection properties. For that, measurements of pore and charge transfer resistances as coating capacitance have been carried out as a function of immersion and hygrothermal ageing times. Their evolutions have shown 3 stages for loss of protection properties, and also the control of phenomena at the metallic interface by barrier properties. Finally, adhesion measurements of the coatings on the metallic substrate complete and confirm previous results. They precise the beneficial effect of the amine on the adhesion and also on the reversibility of that adhesion after drying
Ahledel, Najmeh. "Corrosion resistance and electrochemical behavior of Fe₃Al intermetallic matrix composites reinforced by TiC : Résistance à la corrosion et comportement électrochimique des composites matriciels intermétalliques Fe₃Al renforcés par TiC." Master's thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/32484.
Full textThe corrosion behavior of two Fe₃Al intermetallic matrix composite coatings (Fe₃Al/TiC and Fe₃AlCr/TiC) that prepared by high velocity oxy fuel (HVOF) technique was studied in 3.5 wt.% NaCl solution and compared with non-reinforced Fe₃Al. Furthermore, chromium as an alloying element used in the feedstock of HVOF to evaluate the effect of chromium on corrosion behaviour of the coating. Four electrochemical techniques, open circuit potential potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) were employed to examine corrosion behavior in detail. Post-corrosion analysis was done using Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) to reveal the surface morphology and chemistry of the corroded samples. Results from the open circuit potential test revealed that an oxide layer formed on the coating which could be due to oxidation during the HVOF coating process. The Potentiodynamic polarization graphs revealed that adding TiC particles to Fe₃Al matrix improved the corrosion performance of Fe₃Al so that the Fe₃Al/TiC coatings exhibit slightly six times more corrosion rate. The EIS results indicated a more compact corrosion layer formed on the Cr-added coating resulting into the highest coating resistance. This is supported by the SEM/EDS and XPS analyses which revealed that a mixed oxide and hydroxide formed a passive layer. The Cr in the composite coating took the role in providing a more protective passive layer by blocking the entry sites of Clions. The pitting resistance of the Fe₃Al-Cr/TiC coating in 0.25 M H₂SO₄ solution was, however, lower compared to that of the two other coatings. It is concluded that the addition of TiC particles to Fe₃Al matrix, which primarily done for improving wear resistance, improves the corrosion resistance of the coating in saline solution. The addition of Cr into the Fe₃Al/TiC composite coating further improves its corrosion resistance, but the pitting resistance is not improved when tested in acid solution.
Fievet, Patrick. "Etude statistique de la corrosion par piqûres, par analyse d'images numérisées, d'aciers inoxydables austenitiques : effet de l'implantation ionique de molybdène et d'azote." Toulouse, INPT, 1992. http://www.theses.fr/1992INPT033G.
Full textFenard, Emmanuelle. "Céramiques composites du système Ti/B/N : Propriétés mécaniques et résistance à la corrosion." Limoges, 2001. http://www.theses.fr/2001LIMO0029.
Full textSnogan, Fanny. "Évaluation de la protection contre la corrosion de couches d'anodisation développées sur les alliages d'aluminium 7050 T74 et 2214 T6 : influence de dépôts de carbone pulvérulent." Toulouse, INPT, 2002. http://www.theses.fr/2002INPT009G.
Full textSalacruch, Céline. "Electrodéposition d'alliages zinc-nickel sur acier et post-traitement anti-corrosion sans chrome." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/159/.
Full textThis work deals with the electrodeposition of zinc-nickel alloys from alkaline bath on steel substrate for anti-corrosion applications in the aerospace field. The study of the physicochemical characteristics of deposits, produced from a standard formulation, shows the need to add additives in order to limit the morphological evolution of deposits with the applied current density. An electrochemical study just at the beginning of growing shows that it is possible to determine both the optimal concentrations of metallic cations and the elaboration process of the electrolyte allowing to deposit thick coatings with a nickel content in the range of 13 to 14%mass, with single-phased gamma and uniform microstructure for current densities between 1 and 10 A. Dm-2. To evaluate the embrittlement of steel caused by the hydrogen produced during the electrodeposition, mecanical tests are carried out. They underline the benefit of a coating/substrate interface with high nickel content to avoid the diffusion of hydrogen into steel. However, it has been shown that a thermal post-treatment of deshydrogenation is essential to limit the embrittlement of steel. To increase the anti-corrosion properties of zinc-nickel coatings, a study on a finishing deposit without chromium obtained from sol-gel route has been carried out. After studing the influence of experimental parameters on the characteristics of deposited films, we have shown that, for mechanical high-strength steel, sol-gel deposit confers to zinc-nickel coating a better protection against corrosion than a conversion layer containing hexavalent chromium
Merlatti, Céline. "Etude de la dégradation de matrices organiques et des interfaces dans des systèmes de peinture : contribution à la maîtrise de leur durabilité en environnement humain." Toulon, 2006. http://www.theses.fr/2006TOUL0011.
Full textIn the French Navy, organic coating systems are used to protect ships from corrosion. The service life requirements for protection are a long-term durability of 15 years. Today, the protection is insufficiently durable to meet the requirements, involving important maintenance cost. Thus, coating weatherability testing must be carried out to predict coating failures. The goal of this work is to, first, evaluate whether artificial test is reliable and representative of weathering, secondly, define a new reliable artificial test and finally, understand and identify loss of protection controlling factor. Three anticorrosive systems are studied. Each system presents three layers: topcoat – basecoat – primer. The total width is comprised between 200 and 250 μm. All samples are exposed to four different standard artificial weathering tests: a neutral salt spray test (NSS ISO 9227) and three cycles (QUV ASTM G53, ASTM D5894 and ISO 20340. Besides, the same samples are exposed to a natural weathering during four years in three different locations: Bandol, (83, France) classified as a C3 site, Pipady (83, France) and Kure Beach (North Caroline, USA), classified as C5M sites. Both Kure Beach and Pipady permit to expose coatings to high intensity sunlight in a marine atmosphere. After ageing, the rate of chemical and physico-chemical changes in each layer is followed using different characterisation methods (FTIR Microscopy, Pyrolysis – GC/MS, Dynamical Mechanical Analysis, Vickers Microhardness and SEM). Substrate/primer interface properties are studied by destructive method (the corroded area measurement in the scribing area beneath the coating) and non –destructive methods (Electrochemical Impedance Spectroscopy (EIS), Local EIS, surface potential measure). By comparing the kinds of chemical and physico-chemical changes in the different tests, it is possible to assess the validity of the accelerated tests. QUV ASTM G53, ASTM D5894 and ISO 20340 artificial cycles involve chemical processes which differ from those obtained after natural exposure. Here, the temperature is believed to be a key factor to explain such differences. On the bases of these results, a new cycle has been defined, more reliable. The variety of different weathering conditions permits to determine the more severe conditions in terms of degradation. Coating durability is not directly linked to physicochemical evolution that occurs in the coating. In fact, internal stresses developed during both temperature and moisture cycles control the coating performance
Petit-Etienne, Camille. "Dépôt d'oxyde de silicium par procédé plasma hors équilibre à basse pression et à pression atmosphérique sur de l'acier : application aux propriétés anticorrosion." Phd thesis, Paris 6, 2007. http://tel.archives-ouvertes.fr/tel-00367151.
Full textColin, Alexis. "Vieillissement thermique de peintures anticorrosion : corrélations entre les évolutions de la chimie, de l'architecture macromoléculaire et des propriétés fonctionnelles." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22640.
Full textAnti-corrosive multilayer coatings, or anti-corrosive paints, are used in several industrial applications such as metallic package protection used for transportation or storage of radioactive materials. In working conditions, functional properties of these paints could be degraded under the influence heat or environmental conditions (light, oxygen, moisture …). Such evolutions had been attributed to the aging of the different paint layers that constituted the anticorrosive coating (acrylic-siloxane topcoat, epoxy resin with amine hardener undercoats). In order to properly carry out this study, a « bottom-up multiscale approach » has been developed. This methodology, initially focused on the physico-chemical modifications of neat polymers that constituted each layer of the coating (from chemical structure and macromolecular architecture evolutions to functional properties), is then complexified by adding filers to the paint formulations (pigments, barrier or anti-corrosive particles …). The complete multilayer coating analyses are the last steps of that methodology. The aim of this thesis is to identify and correlate the evolution of anti-corrosive multilayer coating functional properties to the chemical and architectural modifications in each different layer
Orellan, Herrera Juan-Carlos. "Efficacité et effets secondaires des techniques électrochimiques de maintenance des structures en béton armé." Toulouse 3, 2002. http://www.theses.fr/2002TOU30220.
Full textRézel, Dominique Roland. "Structure hyperfine et cinétique de formation des composés de corrosion humide du fer en milieu aqueux chloré : Rôle de la rouille verte 1." Nancy 1, 1988. http://www.theses.fr/1988NAN10494.
Full textBressy, Christine. "Synthèse de revêtements à base de PVDF et de dérivés phosphonés. Application à l'adhérence sur acier et à l'anticorrosion." Montpellier 2, 1996. http://www.theses.fr/1996MON20204.
Full textHilario, Fanny. "Synthèse et caractérisations de nanotubes de TiO2 pour applications biomédicales : propriétés électrochimiques et bioactivité." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI121/document.
Full textTitanium (Ti) is a biocompatible material widely used in the biomedical field, especially for orthopedic implants (for instance hip or knee replacement). It is particularly corrosion resistant and shows remarkable osseointegration properties. However, plane Ti surfaces are not bioactive enough to be implanted; they need to be improved by surface treatments. Surface modification of Ti by anodization enables to synthesize self-organized and vertically aligned TiO2 nanotubes (NTs). This cheap, fast and easily implementable technique also permits a fine tuning of NTs morphology (diameter, length, wall look, etc.). Moreover, since as-anodized NTs are amorphous, crystalline structure may be adjusted by heat treatment, producing anatase structure (450°C) or a mixed structure of anatase and rutile (550°C).Therefore, surfaces of different morphologies and crystalline structures have been synthesized in order to evaluate the influence of these characteristics on corrosion resistance in physiological medium and on bioactivity (hydroxyapatite formation and cell response).We demonstrated that crystallized NTs are more corrosion resistant and more bioactive than amorphous ones or even than flat Ti surfaces. More precisely, considering electrochemical, thermal, mechanical, chemical and bioactive aspects, it seems that mixed NTs of about 720 nm in length and 90 nm in diameter constitute an optimal surface for the present applications.Additionally, in the frame of electrochemical investigations, we focused on modeling experimental results from Electrochemical Impedance Spectroscopy (EIS) measurements. The impedance response of TiO2 NTs in physiological conditions can correspond to porous electrode model as developed by De Levie. However, for non-ideal electrodes, this theory can be generalized and modeled by transmission lines. Thus, the transmission line model developed in this study fits very well with experimental measurements. It suggests that TiO2 NTs are almost non-reactive, justifying their applications in biomedical fields
Pigerre, Jacques. "Contribution au développement d'un dispositif utilisant les ultrasons pour qualifier la durabilité de systèmes de peintures sur support métallique : application aux tôles d'acier galvanisé prélaquées." Antilles-Guyane, 2002. http://www.theses.fr/2002AGUY0078.
Full textNumerous testing procedures have been developed in order to qualify adhesion of organic coatings used for protection of metallic surfaces against corrosion. This work deals with the development of a new test based on ultrasonic solicitation of samples of steel substrates coated with paint films which thickness are lying in a range of 20 to 40 um. The various steps of the design of the experimental equipment and the last improvements are described. The aims of the thesis are the characterisation of mechanical behaviour of the protective film under periodic solicitation in wet medium, the monitoring of the reliability of the manufacturer's process and to try to predict the durability of the manufactured products under tropical conditions. The various experiments point out that water takes an important part during the test. The experimental results collected on the various samples make evidence that mechanical properties depend on the water barrier effect and on the exposure time of the organic coating to the tropical conditions. It is finally demonstrated that the durability of the manufactured products can be related to morphological aspects of the damages types undergone by the samples during the test
Suedile, Fabienne. "Extraction, caractérisation et étude électrochimique de molécules actives issues de la forêt amazonienne pour la protection du zinc contre la corrosion." Thesis, Antilles-Guyane, 2014. http://www.theses.fr/2014AGUY0745/document.
Full textThe objective of this thesis is to focus on the chemistry of na tura! substances (extraction and characterization of molecules from forests of French Guiana) and to study extracts or families ofnatural molecules with inhibiting properties of zinc corrosion. In the first part of the document, a screening of plants was made. Those whose extracts have shown the most interesting potential inhibitors - the Mansoa alliaceae and Bagassa guianensis - were selected among the Il plants studied. In the second part of the paper, different electrochemical techniques were used - the electrochemical impedance spectroscopy (EIS) and linear polarization (LP) - to calculate the inhibition rate and to understand the reaction mechanisms characterizing the inhibition. Thus, the role of parameters such as the method of extraction and the corrosive medium (ASTM and NaCI3%) on the inhibition rate were studied. This work bas led to many new experimental results including a dynamic mode! taking into account the effectiveness of the inhibitor according to its concentration in the medium
Escobar, Claros Cesar Adolfo. "Etude de bioactivité, résistance à la corrosion et comportement en fatigue de l'alliage Ti-12Mo-6Zr-2Fe après différents traitements de surface." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALI051.
Full textDemand for new implants with improved bioactivity, corrosion resistance, and optimal mechanical properties has been increasing considerably. In this sense, different surface treatments are applied in titanium alloys to improve their osteointegration process. Nevertheless, the developments of new bioactive surfaces could cause a considerable reduction in fatigue and corrosion strength leading to catastrophic failures in clinical use. For these reasons, this work studied the biocompatibility, corrosion and fatigue performance of Ti-12Mo-6Zr-2Fe alloy treated with three different surface modifications, namely, chemical surface treatment (CST), nanotubes (Nt) and nanopores (NP). Samples were immersed in simulated body fluid (SBF) solution during different periods, 0, 1, 7, and 14 days. After 14 days immersed in SBF, samples with CST showed high hydroxyapatite (HAp) formation; Likewise, samples with Nt and NP exhibited lower and moderated HAP formation, respectively. In samples without surface treatment was not observed HAp formation. The electrochemical behavior was studied through polarization curves and electrochemical impedance spectroscopy (EIS). Samples with Nt and NP displayed higher corrosion resistance and lower passivation current (Ipass) compared with untreated samples, after 14 days of immersion in SBF; samples with CST showed the worst corrosion performance for all the surface conditions studied. Furthermore, within the framework of electrochemical investigations, EIS results of Nt and NP samples showed a characteristic behavior that could not be modeled by traditional equivalent circuits. Thus, it was proposed a two-channel transmission line model for analyzing this impedance results, leading to a successful fitting of the EIS data. Finally, was observed a reduction of the fatigue resistance in the samples treated with NP and CST, associated with hydrogen embrittlement processes, due to the pick-up of hydrogen during the respective surface treatments