Corrosion is a common issue which must be accounted for when designing all metal products in our society. Many factors need to be considered when new alloys are created, and further knowledge of the corrosion process would be of great use for companies worldwide. The purpose of this thesis was to investigate if X-ray Photoelectron Spectroscopy, XPS, can be used to characterise and quantify corrosion products. With the goal to develop a method that can be used for further studies to increase our understanding of the corrosion process. Aluminium alloy AA3003 was subjected to an immersion corrosion test in an acidified salt solution for different periods of time and the produced chemical compounds were characterised using XPS. The results revealed a direct connection between corrosion time and formed product, which after characterisation proved to be aluminium hydroxide, Al(OH)3. It was concluded that XPS can be used for corrosion studies and is a method that shows great potential and should be further developed. / I metallindustrin är korrosion ett ständigt förekommande problem som måste tas i beaktande vid design av metallprodukter. Många faktorer är avgörande när nya legeringar utvecklas och en djupare kunskap om korrosionsprocessen och dess mekanismer är av stort värde för företag världen över. Syftet med detta examensarbete var att undersöka huruvida röntgen-fotoelektron-spektroskopi, XPS, kan användas för att kvalitativt och kvantitativt karakterisera de korrosionsprodukter som bildas vid korrosion. Med målet att presentera en metod som kan användas för att vidare undersöka och öka vår förståelse för korrosionsprocessen. Aluminiumlegering AA3003 utsattes för accelererad korrosion i en surgjord saltlösning under varierande tid och korrosionsprodukter karakteriserades med XPS. Resultatet påvisade direkt korrelation mellan korrosionstid och mängd produkt. Korrosionsprodukten visade sig vara aluminiumhydroxid, Al(OH)3, och med det i åtanke kunde slutsatsen dras att XPS kan användas vid studier av korrosion. Den utvärderade metoden visar stor potential och detta examensarbete öppnar upp för vidare forskning som kan komma att öka förståelsen för korrosionsprocessen och hur den kan kontrolleras.

O concreto armado era tido, quando da sua concepção inicial, como um material que teria boa durabilidade e uma vida útil elevada, praticamente dispensando reparos. Com a intensificação de seu uso, todavia, começaram a serem observados diversos processos de deterioração que resultaram, nos casos mais críticos, em severos comprometimentos de desempenho ou falhas prematuras. Dentre as manifestações patológicas que mais transtorno e prejuízos causam às estruturas civis, destaca-se a corrosão de armaduras, por sua elevada incidência e potencial de dano. Embora já exista um considerável número de pesquisas acerca deste tema, percebe-se que a ênfase atual se encontra no estudo do processo de iniciação da corrosão, e poucos estudos se voltam para a caracterização da fase de propagação, onde os danos se intensificam. Assim, esta pesquisa tem a finalidade, pela realização de experimentos conjugados com uma análise numérica, de contribuir para que sejam entendidos os efeitos, em termos de prejuízo do desempenho estrutural, da propagação da corrosão em estruturas civis. Para fins desta pesquisa, consideraram-se como efeitos significativos nas propriedades estruturais: a perda da aderência entre o aço e o concreto; a diminuição da área de seção transversal da armadura; a diminuição da resistência à tração do aço; e o aparecimento de tensões de tração devido ao acúmulo dos produtos de corrosão junto às barras. Foi estimulado o desenvolvimento de processos de corrosão em corpos-de-prova de concreto contendo barras de aço, que usa aplicação de corrente constante e exposição a uma solução de cloretos, e os graus de corrosão estudados foram equivalentes a perdas de massa de 0, 2, 5, 10 e 20%. Os resultados obtidos nesta fase experimental foram empregados como referência para uma análise numérica, cuja validação foi feita pela avaliação de vigas moldadas e deterioradas em laboratório pelo processo de corrosão induzido. Os resultados da pesquisa mostram, em suma, que os corpos-de-prova de concreto afetados pela corrosão de armaduras, devido ao ataque por cloretos, com pequenas perdas de massa (da ordem de 2 e 5%) não apresentam danos significativos nas propriedades estruturais, enquanto que nos corpos-de-prova contaminados com graus de corrosão maiores que 10% estes danos são mais evidenciados, e neste caso as estruturas devem ser obrigatoriamente tratadas ou recuperadas nos casos mais críticos. / When reinforced concrete was designed, it was believed to be a material with good durability and great life-cycle, with almost no repairs necessary. With its use intensification, however, it started to be noticed several deterioration processes and, in the most critical cases, these deterioration processes severely compromised the structure performance or leaded to early fails. Among the pathological manifestations which cause more damages to civil structures, it is possible to highlight the reinforcement corrosion due to its great incidence and damage potential. Despite the great amount of researches concerning this issue, the up-to-date emphasis is based on the corrosion initiation process study, and fewer studies focus on the propagation phase characterization, in which damages are intensified. This research aims, trough experimental and numerical analysis, to contribute for a better understanding of the effects, regarding structural performance damage, of corrosion propagation in civil structures. In this research it is considered as important effects on structural proprieties: losses of bond between steel and concrete; the bar cross section reduction; the bar tensile strength reduction; and the development of tension efforts due to rust near the bars. It was stimulated the development of corrosion process in concrete specimens with rebars, which uses constant current impression and chloride solution exposition to accelerate the corrosive process, and the corrosion levels studied were equivalent to bar weight losses of 0, 2, 5, 10 and 20%. The results from this experimental phase were used as reference to numerical analysis, and validated by beams which were cast and deteriorated in laboratory due to inducted corrosion process. The research results show, in a few words, that concrete specimens affected by reinforcement corrosion, due to chloride attack, with low levels of mass losses (approximately 2 and 5%) do not present significant structural properties damages, while in the specimens with corrosion levels higher then 10% these damages are more exposed, and in this case the structures should be obligatory treated or recovered in the most critical cases.

La corrosion de l’acier par carbonatation du béton est un phénomène de dégradation majeur des structures en béton armé, qui débute par la dépassivation de l'acier due à l'abaissement du pH de la solution interstitielle, se concrétise par une initiation effective avant de se propager. Nous nous sommes focalisé sur la dépassivation et l'initiation effective. Une large campagne expérimentale a permis de comprendre l'incidence des conditions d'exposition, de la nature des ciments utilisés dans les bétons et des conditions de carbonatation de l'enrobage, sur la dépassivation des armatures et le démarrage effectif de la corrosion. Au total 27 configurations ont été étudiées. Le potentiel libre de corrosion et la résistance de polarisation ont été mesurés au cours de l'expérimentation sur une durée voisine d'une année. Parallèlement, à échéances régulières, les coefficients de Tafel et la masse de produits de corrosion ont été également mesurés. L'ensemble des données a été analysé pour conduire, à partir du calcul des probabilités de bonne ou de mauvaise alarme, aux seuils de détection du démarrage effectif de la corrosion associés aux paramètres électrochimiques ainsi que la masse seuil de produits de corrosion correspondant à cette détection. Alimentée par les résultats des essais de caractérisation des bétons, une simulation numérique par éléments finis du démarrage de la corrosion a été développée permettant de corroborer de façon satisfaisant les résultats expérimentaux / The steel corrosion induced by carbonation is a major cause of degradation of the reinforced concrete structures. Two stages arise: the steel depassivation due to the decrease of pH of the pore solution and the effective initiation, and then the propagation. A wide experimental study was carried out focusing on the first stage, in order to emphasize the effect of the exposure conditions, the type of cement and the concrete mixes, and the carbonation conditions of the concrete cover. In all a set of 27 configurations was investigated. The free potential of corrosion and the resistance of polarization were measured in the course of the experiment during one year. Regularly the Tafel coefficients along with the mass of corrosion products were also measured. The set of data was analyzed in order to derive the detection thresholds of the effective onset of corrosion associated with the electrochemical parameters, from the calculation of the probabilities of good or bad alarm. The threshold of the mass of corrosion products corresponding to this detection was also derived. The tests on concrete probes (porosity, permeability, etc.) supplied data that were used to calibrate a finite element model of the onset of corrosion: this model was found in fairly good agreement with the experimental results

Le béton armé est sans conteste le matériau le plus utilisé dans la construction, et permet de réaliser la plupart des infrastructures dans tous les pays du monde. Cependant, sa durabilité peut être compromise de façon prématurée par la corrosion des aciers, qui est la pathologie considérée comme la plus dangereuse vis-à-vis du maintien de l'intégrité des ouvrages de Génie Civil. Afin d'obtenir une meilleure résistance face au risque de corrosion, l'acier conventionnel (AC) peut être soumis à divers traitements, dont les plus connus sont le recouvrement superficiel par d'autres matériaux métalliques à base de zinc (AG), ou par des revêtements doubles métal-polymères (AD). Cependant, il existe aussi des barres d'acier thermiquement traitées (ATT) qui ne sont actuellement quasiment pas utilisées en tant qu'armatures. De ce fait, leur comportement face aux mécanismes de détérioration comme la corrosion en milieu cimentaire causée par les chlorures ou la carbonatation est encore très peu connu. Dans ce travail, le comportement des différentes barres d'acier mentionnées ci-dessus a été étudié. Des éprouvettes prismatiques de béton, incluant ces types d'armatures, ont été fabriquées avec deux rapports E/C : 0,45 et 0,65. Avant leur utilisation, les barres ont été caractérisées mécaniquement et métallographiquement. Ensuite, les éprouvettes ont été placées dans différentes conditions d'exposition : un environnement urbain/industriel ou côtier, et un environnement contrôlé en laboratoire. Des mesures du potentiel de corrosion, de résistance de polarisation linéaire, et de spectroscopie d'impédance électrochimique ont été mises en œuvre durant la période d'exposition. Pour chaque série, la teneur critique en chlorures a été déterminée, et la progression de la profondeur de carbonatation a été suivie. En outre, en induisant un couple galvanique par effet de la carbonatation, des mesures originales du comportement électrochimique de ces barres ont été effectuées puis une analyse, en s'appuyant sur une modélisation en éléments finis, en a été faite. Dans l'environnement contrôlé en laboratoire, l'ordre de dépassivation des différentes barres exposées a été observé de façon similaire pour les deux rapports E/C, à savoir : ATT, AC, AG et enfin AD. Une teneur critique en chlorures plus élevée a été obtenue pour les barres AG et AD. Cependant, lors de l'inspection visuelle, les dommages causés sur les armatures AG étaient plus élevés que sur les autres types de barres. Enfin, durant l'étape de propagation, la densité de courant de corrosion des barres ATT et des barres AG s'est révélée inférieure. / Corrosion of reinforcing bars in concrete is considered as the most important problem that affects the integrity of the civil structures. In order to obtain a better resistance to corrosion, various superficial processes as coatings with zinc (AG) or such as the dual covering metallic-polymeric (AD) are applicate to ordinary steel bars (AC). On the other hand, steel bars with thermal treatments (ATT), principally developed as an alternative to improve the mechanical properties without the use of ferroalloys, are not used in concrete. The behavior of these kinds of bars in front of mechanisms of deterioration as the corrosion induced by chlorides or carbonation has not yet been studied. In this work, all these various steel bars (AG, AD, AC and ATT) were embedded in prismatic specimens of concrete made with two ratio water/cement: 0.45 and 0.65. Previously, steels bars were characterized by mechanical tests and metallographic identifications. Then, specimens were placed in several sites of exposition: urban/industrial environment, or coastal environment, or controlled atmosphere in laboratory. During these expositions, measurements of corrosion potential, linear polarization resistance, and electrochemical impedance spectroscopy were regularly carried out. For each type of steel bar, chloride threshold level and progress of the carbonation depth were determined. Furthermore, by means of the induction of a galvanic couple during design of new samples, the electrochemical behavior of the steels bars AC, ATT and AG was followed up experimentally and then analyzed with finite element model. It was founded that the different steels bars exposed in controlled atmosphere of laboratory followed a same sequence in depassivation for both ratios water/cement: ATT, AC, AG and AD. The chloride thresholds were higher for steels bars AG and AD. However, visual inspection showed that the morphology of damages caused on AG bars was most important compared with the other steel bars. In the propagation phase, the corrosion current density of the ATT bars was lower, even to that obtained by the AG bars.

No presente trabalho analisa-se o comportamento do aço de reforço ante à corrosão, com o uso dos inibidores: nitrito de sódio, fosfato de sódio e etalonamina, na água de poros contaminada com cloreto, e no concreto com a finalidade de analisar seus resultados e seus mecanismos diferenciados. Para cumprir este objetivo o presente trabalho divide-se em duas etapas: uma primeira etapa baseada em simular sinteticamente a água de poro de um concreto, cuja solução é KOH 28g/l+NaOH 4g/l. Essa água de poro é simulada em ambiente marinho, cuja solução é KOH 28g/l + NaOH 4g/l+NaCl 35g/l, e a esta solução referência incorporamse os inibidores (20g/l da cada um). Realizaram-se ensaios de espectroscopia de impedância eletroquímica (EIE) (após 3 e 72 horas de imersão) e curvas de polarização (após 72 horas de imersão) com vistas a obter respostas da cinética da corrosão ante a cada solução. Obteve-se o melhor comportamento para a água de poros. No caso da água de poro contaminada por cloretos, o melhor comportamento se obteve para o inibidor nitrito de sódio. Na segunda etapa adotou-se apenas o inibidor nitrito de sódio, pois estatisticamente as eficiências dos três inibidores foram muito similares. Analisou-se o nitrito de sódio em amostras reais de concreto armado contaminado com cloreto de sódio. Para isso se elegeram dois tipos de cimentos (CP IV e CP V) e três relações água-cimento (a/c-0.4, a/c-0.5, a/c- 0.65). Para simular o ambiente marinho, realizaram-se ensaios acelerados de cloretos. Comparam-se métodos de análises simuladas sinteticamente e reais, concluindo-se em ambos meios, embora fossem um solido e outro líquido o inibidor Nitrito de Sódio aumento a sua eficiência com os ciclos de exposição. / In this paper it is analyzed the behavior of reinforcing steel against corrosion using inhibitors: sodium nitrate, sodium phosphate and ethanolamine in water contaminated with chlorides pore and concrete, in order to analyzing the results and different mechanisms. To meet the objective of this work, it was divided into two stages, a first stage based on synthetically simulate the pore water of a concrete, through the following solution KOH 28g/l+NaOH 4g/l, this same solution simulated pore water to a marine environment it would be KOH 28g/l + NaOH 4g/l+NaCl 35g/l, it is then incorporated into both reference solutions inhibitors in a proportion, (20g/l de cada um). Assays were performed electrochemical impedance spectroscopy (EIE) (last 3 hours and 72 hours of immersion) and polarization curves (last 72 hours of immersion) in order to obtain responses corrosion kinetics in each solution. the best performance was obtained in the pore water. In the case of water contaminated with chlorides pore, the best performance was obtained in the presence of sodium nitrite inhibitor. In the second step was performed only with the inhibitor sodium nitrate, as statistically efficiencies of the three inhibitors were similar. Sodium nitrate was analyzed in real samples of reinforced concrete contaminated with chlorides of sodium. So they were chosen two types of cement CP- IV and CP-V, cement water three relationships 0.4, a/c-0.5, a/c- 0.65. In this case to simulate the marine environment, accelerated tests were performed chloride. They were compared the methods of analysis, simulated synthetically and simulated in real concrete.

Polímeros heterocíclicos são macromoléculas de elevado desempenho que incluem uma grande variedade de materiais, desde simples polímeros lineares preparados a partir de monômeros do tipo heterocíclicos vinílicos, até polímeros funcionalizados e reticulados. Neste trabalho realizou-se a modificação química da poliacrilonitrila com a incorporação de grupos 2-vinil-2-oxazolina em diferentes teores (10% e 20%). Os copolímeros de acrilonitrila e 2-vinil-2-oxazolina obtidos foram caracterizados por espectroscopia na região do infravermelho e o seu comportamento térmico analisado por calorimetria diferencial de varredura e análise termogravimétrica. Os copolímeros heterocíclicos foram avaliados como inibidores de corrosão para aço-carbono em solução aquosa de HCl 10%, alcançando, em alguns casos, uma eficiência de inibição superior a 75%, com diferença estatisticamente significativa (P < 0,05, ANOVA) para a poliacrilonitrila não modificada. / Heterocyclic polymers are high-performance macromolecules that include a variety of materials, from simple linear polymers which are prepared from heterocyclic monomers like vinyl, to functionalized polymers or lattices. In this work polyacrylonitrile was chemically modified with incorporation of 2-vinyl-2-oxazoline groups at different contents (10% and 20%). Copolymers of acrylonitrile and 2-vinyl-2-oxazoline were characterized by spectroscopy in the infrared region, differential scanning calorimetry and thermogravimetric analysis. The synthesized heterocyclic copolymers were evaluated as corrosion inhibitor on carbon steel against aqueous solution of HCl 10%, and in some cases inhibition efficiencies more than 75% were determined, with statistically significant difference (P < 0.05, ANOVA) to the unmodified polyacrylonitrile.

A corrosão é um processo resultante da ação do meio sobre um determinado material, causando sua deterioração. Em geral, essa deterioração causa prejuízos incalculáveis, fazendo com que o material se torne inadequado ao uso. Os heterocíclicos apresentam inúmeras aplicações tecnológicas e em alguns casos médico-farmacológicas. Mais recentemente, esses compostos têm sido utilizados como eficientes inibidores de corrosão para a proteção de metais em meio ácido ou salino. Nesta Dissertação realizou-se a modificação química da poliacrilonitrila com a incorporação de grupos tetrazol em diferentes teores (8%, 15%, 30% e 30%). Os copolímeros de acrilonitrila e 5-vinil-tetrazol obtidos foram caracterizados por espectroscopia na região do infravermelho e foram quantificados os respectivos teores de incorporação por meio de titulação ácido-base e análise elementar. A poliacrilonitrila e os copolímeros heterocíclicos foram avaliados como inibidores de corrosão para aço-carbono, alumínio e latão em solução aquosa de HCl 2 mol/L e HNO3 2 mol/L, alcançando, em alguns casos, uma eficiência de inibição superior a 75%, com diferença estatisticamente significativa (P < 0,05, ANOVA) para a poliacrilonitrila não modificada / Corrosion is a process resulting from the action of environment on a given material, causing its deterioration. In general, these deteriorations cause incalculable damage, making the material unsuitable for use. The heterocycles have numerous technological applications and in some cases medical and pharmacological. More recently, these compounds have been used as efficient corrosion inhibitors to protect metals in acidic or saline environments. This Dissertation was conducted on the chemical modification of polyacrylonitrile with the incorporation of tetrazole at different contents (8%, 15%, 30% and 30%). Copolymers of acrylonitrile and 5-vinyl-tetrazole were characterized by infrared spectroscopy and were quantified the respective contents of incorporation by acid-base titration and elemental analysis. The polyacrylonitrile and heterocyclic copolymers were evaluated as corrosion inhibitors for carbon steel, aluminum and brass in aqueous 2 mol/L HCl and 2 mol/L HNO3, resulting in some cases, an efficiency of greater than 75% inhibition, which was statistically significant (P<0.05, ANOVA) for the unmodified polyacrylonitrile

Dans le cadre de la fabrication de pièces structurales pour l’industrie aéronautique, de nouveaux matériaux composites à matrice céramique sont envisagés par le motoriste Safran. Lors de l’utilisation dans des environnements sévères de combustion, et sous chargement mécanique, la matrice pourra s’endommager par fissuration et la capacité du matériau à s’auto-protéger sera réduite. Les travaux présentés dans cette thèse ont pour but d'identifier les mécanismes prépondérants de ruine de ce type de matériaux composites en fonction de différentes sollicitations thermiques, mécaniques et environnementales. Une démarche multi-échelle a été adoptée, de manière à considérer les phénomènes à une échelle microscopique (chaque constituant) et macroscopique (synergie entre les constituants au sein du matériau). Le comportement en oxydation/corrosion du matériau composite et de chacun de ses constituants a été caractérisé puis modélisé pour être extrapolé à des environnements de combustion. Différents domaines de protection du matériau ont ainsi été mis en évidence. Dans cette même optique, le comportement thermomécanique des constituants matriciels et du composite a fait l’objet d’essais de fluage pour déterminer les paramètres d’une première modélisation, et analyser les dégradations associées. En couplant les différents résultats obtenus, il est ainsi possible d’évaluer la criticité des différents phénomènes de ruine. Des scenarii de ruine sont donc présentés. / To design and manufacture CMC structural components for aeronautics, Safran develops a new CMC grade, provided to resist severe combustion environments. Understanding this new composite material damaging and failure mechanisms is essential: environmental conditions, mechanical loading, and matrix damages, can lead to a decrease in its self-protective properties. The aim of this work is to identify prevailing high temperature degradation mechanisms of those MI SiC/SiC CMCs, depending of different thermal, mechanical and environmental stresses. To fulfill that outcome, a multi-scale approach was considered, by examining phenomena from single constituents to complex composite architecture (effects of constituents’ synergy). High temperature oxidation/corrosion behaviors of the composite material and each of its constituents were characterized, and modeled to meet representative combustion environment. Different operating areas of efficient self-protection of the composite material were therefore highlighted. In the same perspective, themomechanical behaviors of both matrix constituents and composite were experimentally explored, enabling the determination of behavior laws. Related degradations in the composite material were also analyzed. Crossing all results, it was thereby possible to evaluate kinetics and criticality of failure mechanisms: different damaging scenarios are thus proposed, depending on environmental conditions.

Les vibrations issues du fonctionnement d'un véhicule automobile (moteur, route) sont transmises aux connecteurs électriques. Ces vibrations peuvent induire des déplacements relatifs entre certains des composants du connecteur à l’interface de contact. Les éléments en contact sont de diverses formes et diverses natures dont une partie femelle (dite clip) dans laquelle s’introduit une partie mâle (dite languette). Or, un déplacement relatif de quelques micromètres entre le clip et la languette est suffisant pour dégrader et ce de manière irréversible, l'interface de la zone de contact électrique (phénomène de fretting-corrosion). Il est donc nécessaire de connaître le comportement vibratoire interne d'un connecteur i.e. des connectiques pour préconiser sa meilleure son utilisation au sein d'un véhicule. Un banc d'essai sur pot vibrant a été réalisé dans le but de caractériser le comportement vibratoire d'un connecteur soumis à un profil vibratoire. Les mesures ont été réalisées par tribométrie en réalisant des orifices d'accès au clip et à la languette. De là, l'analyse des vibrations induites a mis en évidence des directions de déplacement multi-axiales des composants du connecteur et notamment celles d’un support du clip dit porte-clip, et ce malgré une vibration dont la direction est mono-axiale. L'analyse a également mis en évidence une correspondance vibratoire entre le clip et le porte-clip ainsi que des phénomènes de résonances. De là, une première approche sur une modélisation numérique, basée sur un système masse-ressort-amortisseur, a été proposée. Cette analyse permet de caractériser le comportement vibratoire général d'un connecteur sans dépendre du type de vibration appliquée. C'est une nouvelle approche dans la caractérisation de connecteurs électriques utilisés dans l’industrie automobile. Les éléments en contact d’un connecteur sont revêtus de matériaux qui les protègent des dégradations mécaniques et chimiques. Ces revêtements (de quelques micromètres d’épaisseur) peuvent être des matériaux nobles (or, argent,…) ou non nobles (étain, …). Le déplacement relatif entre un clip étamé et une languette étamée engendre la formation d'un troisième corps à l'interface de contact. Ce troisième corps est composé de débris oxydés qui perturbent la conduction des charges électriques. L'utilisation d'une atmosphère de di-azote (N2) et l’analyse de la tension de contact en fonction de l'emplacement du clip par rapport à la languette ont mis en évidence la dynamique des débris oxydés avec notamment leur évacuation hors de la zone de contact. De plus, l'analyse d'une zone de contact dégradée à la microsonde nucléaire a permis de doser l'oxygène et de mettre en valeur deux types d'oxydes de cuivre. Ces caractérisations permettent de mieux comprendre le phénomène de fretting-corrosion et ses conséquences. / Vibrations are generating from an operating vehicule (motor, road). Then, they are transmitted to electrical connectors. Therefor, these vibrations can induce relative displacements between some of the connector components. The components for the electrical contact are the female part (called a clip) and the male part (called the tongue).These components are coated with materials that protect them from mechanical and chemical degradation. These coatings (a few micrometers thick) can be noble materials (gold, silver,...) or not noble (tin). A relative displacement of a few micrometers between the clip and the tongue is sufficient to irreversibly degrade the interface of the electrical contact zone by fretting-corrosion phenomenon. It is therefore necessary to know the internal vibratory behavior of connectors in order to recommend its best use for a vehicle.A test bench is carried out in order to characterize the vibratory behavior of a connector subjected to a vibratory profile. The measurements are carried out by vibrometry by making holes access for the clip and the tongue. From there, the analysis of the induced vibrations has revealed multi-axial directions displacements of the components of the connector and in particulary the clip holder (external support of the clip), despite a vibration whose direction is mono-axial.The analysis also showed a vibratory correspondence between the clip and the clip holder and resonance phenomena. From there, a first approach on a numerical modeling, based on a system mass-spring-damper, has been proposed. This analysis makes it possible to characterize the general vibratory behavior of a connector without depending on the type of vibration applied. This is a new approach in the characterization of electrical connectors used in the automotive industry.The relative movement between the clip and the tongue induce formation of a third body at the contact interface. This third body is composed of tin oxidized remains which disturb the conduction of electrical charges due to their electrcail insulating characteristic. The use of a nitrogen atmosphere and the analysis of the contact voltage as a function of the location of the clip relative to the tongue have demonstrated the dynamics of the oxidized debris with, in particular, their evacuation out of the contact area. Moreover, the analysis by a nuclear microprobe of a zone degraded contact area enable the measurement of oxygen concentration. The results hilight two types of copper oxides. These characterizations make it possible to better understand the phenomenon of fretting-corrosion and its consequences.

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