Degradation mechanisms in martensitic stainless steels: wear, corrosion and tribocorrosion appraisal

[EN] A deep understanding of degradation mechanisms of metals is crucial for developing new materials with high performance. Within the different families of stainless steels, martensitic stainless steels are widely used in a great variety of industrial applications where mechanical properties, such as strength, wear resistance and fatigue behavior, need to be high. In many of those applications, such as bearings or gears, martensitic stainless steels may be subject to tribological conditions leading to wear. Furthermore, when a contact operates in a corrosive environment its deterioration can be significantly affected by surface chemical phenomena, leading to a tribocorrosion degradation mechanism. Indeed, martensitic stainless steels degrade through a great variety of wear and corrosion mechanisms. This paper aims to review the published data from 2005 to present related to wear, corrosion and tribocorrosion of martensitic stainless steels. Individual studies of tribological and corrosion behavior of martensitic stainless steels have been widely published since 2005. From the wear point of view, ploughing or abrasive wear in dry contacts involving martensitic stainless steel has been reported, while pitting corrosion is the most common mechanism for those steels. However, only nine papers were found since 2005 related to tribocorrosion of martensitic stainless steels, although most authors concluded that this joint action is the most important material degradation in martensitic stainless steels.Dalmau-Borrás, A.; Richard, C.; Igual Muñoz, AN. (2018). Degradation mechanisms in martensitic stainless steels: wear, corrosion and tribocorrosion appraisal. Tribology International. 121:167-179. https://doi.org/10.1016/j.triboint.2018.01.036S16717912

Influence of pH on the electrochemical behaviour of a duplex stainless steel in highly concentrated LiBr solutions

[EN] The objective is to study the influence of pH on the corrosion and passive behaviour of duplex stainless steels (DSS) using potentiodynamic measurements, potentiostatic tests and electrochemical impedance spectroscopy (EIS). DSS are spontaneously passive in heavy brine LiBr solutions. Under potentiostatic conditions at applied anodic potentials within the passive domain an equivalent circuit with two time constants is the most suitable model to describe the corrosion mechanism in the interface electrolyte/passive film/metal. pH modifies the electrochemical properties of the passivity of the alloy in a 992. g/L LiBr solution reducing its resistance with the applied potentialWe wish to express our gratitude to MCYT (CTQ2009-07518), to Feder and to Dr. M. Asunción Jaime for her translation assistanceGuiñón Pina, V.; Igual Muñoz, AN.; García Antón, J. (2011). Influence of pH on the electrochemical behaviour of a duplex stainless steel in highly concentrated LiBr solutions. Corrosion Science. 53(2):575-581. https://doi.org/10.1016/j.corsci.2010.09.066S57558153

Tribocorrosion Mechanisms of Ti6Al4V in Artificial Saliva by Zero-Resistance Ammetry (ZRA) Technique

[EN] Degradation mechanisms of biomedical alloys involve two different phenomena, corrosion and wear, which simultaneously act and may cause the failure of implants and prosthesis. In this work, tribocorrosion of Ti6Al4V biomedical alloy in artificial saliva is studied at open circuit potential (OCP) by a new electrochemical technique that allows measuring the galvanic potential and current between the wear track (anode) and the passive material (cathode) through zero-resistance ammetry. The experimental set-up was conceived for physically separating the depassivated area from the passive material, thus allowing to quantify the mechanically activated corrosion at OCP. Two different counterparts, SiC and Al2O3, were used against the Ti6Al4V alloy in order to analyse the influence of the initial contact pressure on the tribocorrosion mechanisms. A galvanic model based on the cathodic reaction kinetics can describe the current and the potential evolution with time during sliding. It has been observed that at the highest initial contact pressures, wear follows the Archard law, while at lower contact pressures, third body appeared and wear can not be described by the Archard law. Quantification of the evolution of the depassivated wear track with time was obtained and the deviation from the Archard predictions was analysed.The authors would like to thank the financial support from NTNU (Project Number 69450741) for performing the experiments of this work and Universitat Politècnica de Valencia VLC/Campus (PMIA-2013) for the mobility Grant.Licausi, M.; Igual Muñoz, AN.; Amigó, V.; Espallargas, N. (2015). Tribocorrosion Mechanisms of Ti6Al4V in Artificial Saliva by Zero-Resistance Ammetry (ZRA) Technique. Journal of Bio- and Tribo-Corrosion (Online). 1(8):1-11. https://doi.org/10.1007/s40735-015-0008-xS11118Martin É, Azzi M, Salishchev GA, Szpunar J (2010) Influence of microstructure and texture on the corrosion and tribocorrosion behaviour of Ti–6Al–4V. Tribol Int 43:918–924Nosonovsky M, Bhushan B (2010) Green tribology: principles, research areas and challenges. Philos Trans R Soc A 368:4677–4694Geetha M, Singh AK, Asokamani R, Gogia AK (2009) Ti based biomaterials, the ultimate choice for orthopaedic implants—a review. Prog Mater Sci 54:397–425Niinomi M, Kuroda D, Fukunaga K, Morinaga M, Kato Y, Yashiro T et al (1999) Corrosion wear fracture of new β type biomedical titanium alloys. Mater Sci Eng A 263:193–199Kuroda D, Niinomi M, Morinaga M, Kato Y, Yashiro T (1998) Design and mechanical properties of new β type titanium alloys for implant materials. Mater Sci Eng A 243:244–249Eisenbarth E, Velten D, Müller M, Thull R, Breme J (2004) Biocompatibility of β-stabilizing elements of titanium alloys. Biomaterials 25:5705–5713More NS, Diomidis N, Paul SN, Roy M, Mischler S (2011) Tribocorrosion behaviour of β titanium alloys in physiological solutions containing synovial components. Mater Sci Eng C 31:400–408Milošev I, Metikoš-Huković M, Strehblow H-H (2000) Passive film on orthopaedic TiAlV alloy formed in physiological solution investigated by X-ray photoelectron spectroscopy. Biomaterials 21:2103–2113Komotori J, Hisamori N, Ohmori Y (2007) The corrosion/wear mechanisms of Ti–6Al–4V alloy for different scratching rates. Wear 263:412–418Dimah MK, Devesa Albeza F, Amigó Borrás V, Igual Muñoz A (2012) Study of the biotribocorrosion behaviour of titanium biomedical alloys in simulated body fluids by electrochemical techniques. Wear 294–295:409–418Licausi MP, Igual Muñoz A, Amigó Borrás V (2013) Tribocorrosion mechanisms of Ti6Al4V biomedical alloys in artificial saliva with different pHs. J Phys D 46:404003Runa MJ, Mathew MT, Rocha LA (2013) Tribocorrosion response of the Ti6Al4V alloys commonly used in femoral stems. Tribol Int 68:85–93Munoz AI, Espallargas N (2011) Tribocorrosion mechanisms in sliding contacts. In: Landolt D, Mischler S (eds) Tribocorrosion of passive metals and coatings. Woodhead Publishing, LausanneMischler S (2008) Triboelectrochemical techniques and interpretation methods in tribocorrosion: a comparative evaluation. Tribol Int 41:573–583Espallargas N, Johnsen R, Torres C, Muñoz AI (2013) A new experimental technique for quantifying the galvanic coupling effects on stainless steel during tribocorrosion under equilibrium conditions. Wear 307:190–197Vieira AC, Rocha LA, Papageorgiou N, Mischler S (2012) Mechanical and electrochemical deterioration mechanisms in the tribocorrosion of Al alloys in NaCl and in NaNO3 solutions. Corros Sci 54:26–35Papageorgiou N, Mischler S (2012) Electrochemical simulation of the current and potential response in sliding tribocorrosion. Tribol Lett 48(3):271–283Papageorgiou N, von Bonin A, Espallargas N (2014) Tribocorrosion mechanisms of NiCrMo-625 alloy: an electrochemical modeling approach. Tribol Int 73:177–186Dearnley PA, Dahm KL, Çimenoglu H (2004) The corrosion-wear behaviour of thermally oxidised CP-Ti and Ti-6Al-4V. Wear 256:469–47

Passivation of a CoCrMo PVD Alloy with Biomedical Composition under Simulated Physiological Conditions Studied by EQCM and XPS

Kinetics of passive film growth on a CoCrMo biomedical alloy have been studied using the Electrochemical Quartz Crystal Microbalance technique (EQCM) in phosphate buffer solution at room temperature and 37◦C. CoCrMo layers were deposited on the quartz crystals by physical vapor deposition (PVD) reaching a dense and compact deposition film with fine-grain structure. EQCM measurements were performed under potentiodynamic and potentiostatic conditions (at applied passive and transpassive potentials). Furthermore, ex-situ X-ray Photoelectron Spectroscopy (XPS) analysis of the each tested sample was performed at the end of the electrochemical test. The use ofEQCMallows distinguishing between electrochemical oxidation, passive and transpassive dissolution and passive film growth. In the passive domain the passive film thickness stabilizes within 200 to 400 s after an initial fast growth. The increase in current at the onset of the transpassive domain does not affect the passive dissolution rate. Only at higher potential dissolution rate increases due to the dissolution of Cr(VI), Co(III) and Mo(VI) species. The observed constant mass loss rate at transpassive potentials indicates that the passive film at these potentials is cracked or porous. Increasing temperature accelerates themass loss through the oxide/electrolyte interface enhancing the passive and transpassive dissolution and increasing the thickness of the oxide filmWe wish to express our gratitude to the Spanish Government, "Ministerio de Educacion" for the economic support and the post-graduate grant (Ref.AP2007-01243) and "Ministerio de Ciencia e Innovacion" for the financial support (Ref.MAT2011-22481), the assistance of N. Xanthopoulos with the XPS measurements and P. Mettraux with the PVD deposits and assistance with the scanning electron micrographs.Valero Vidal, C.; Igual Muñoz, AN.; Olsson, C.; Mischler, S. (2012). Passivation of a CoCrMo PVD Alloy with Biomedical Composition under Simulated Physiological Conditions Studied by EQCM and XPS. Journal of The Electrochemical Society. 159(5):233-243. https://doi.org/10.1149/2.090205jesS2332431595Katti, K. S. (2004). Biomaterials in total joint replacement. Colloids and Surfaces B: Biointerfaces, 39(3), 133-142. doi:10.1016/j.colsurfb.2003.12.002Okazaki, Y. (2002). Effect of friction on anodic polarization properties of metallic biomaterials. Biomaterials, 23(9), 2071-2077. doi:10.1016/s0142-9612(01)00337-4Virtanen, S., Milošev, I., Gomez-Barrena, E., Trebše, R., Salo, J., & Konttinen, Y. T. (2008). Special modes of corrosion under physiological and simulated physiological conditions. Acta Biomaterialia, 4(3), 468-476. doi:10.1016/j.actbio.2007.12.003Milošev, I., & Strehblow, H.-H. (2003). The composition of the surface passive film formed on CoCrMo alloy in simulated physiological solution. Electrochimica Acta, 48(19), 2767-2774. doi:10.1016/s0013-4686(03)00396-7Hodgson, A. W. E., Kurz, S., Virtanen, S., Fervel, V., Olsson, C.-O. A., & Mischler, S. (2004). Passive and transpassive behaviour of CoCrMo in simulated biological solutions. Electrochimica Acta, 49(13), 2167-2178. doi:10.1016/j.electacta.2003.12.043Muñoz, A. I., & Mischler, S. (2007). Interactive Effects of Albumin and Phosphate Ions on the Corrosion of CoCrMo Implant Alloy. Journal of The Electrochemical Society, 154(10), C562. doi:10.1149/1.2764238Hanawa, T., Hiromoto, S., & Asami, K. (2001). Characterization of the surface oxide film of a Co–Cr–Mo alloy after being located in quasi-biological environments using XPS. Applied Surface Science, 183(1-2), 68-75. doi:10.1016/s0169-4332(01)00551-7Hanawa, T. (2004). Metal ion release from metal implants. Materials Science and Engineering: C, 24(6-8), 745-752. doi:10.1016/j.msec.2004.08.018Fleury, C., Petit, A., Mwale, F., Antoniou, J., Zukor, D. J., Tabrizian, M., & Huk, O. L. (2006). Effect of cobalt and chromium ions on human MG-63 osteoblasts in vitro: Morphology, cytotoxicity, and oxidative stress. Biomaterials, 27(18), 3351-3360. doi:10.1016/j.biomaterials.2006.01.035Germain, M. A., Hatton, A., Williams, S., Matthews, J. B., Stone, M. H., Fisher, J., & Ingham, E. (2003). Comparison of the cytotoxicity of clinically relevant cobalt–chromium and alumina ceramic wear particles in vitro. Biomaterials, 24(3), 469-479. doi:10.1016/s0142-9612(02)00360-5Massè, A., Bosetti, M., Buratti, C., Visentin, O., Bergadano, D., & Cannas, M. (2003). Ion release and chromosomal damage from total hip prostheses with metal-on-metal articulation. Journal of Biomedical Materials Research Part B: Applied Biomaterials, 67B(2), 750-757. doi:10.1002/jbm.b.10070Dumbleton, J. H., & Manley, M. T. (2005). Metal-on-Metal Total Hip Replacement. The Journal of Arthroplasty, 20(2), 174-188. doi:10.1016/j.arth.2004.08.011Milo?ev, I., & Strehblow, H.-H. (2000). The behavior of stainless steels in physiological solution containing complexing agent studied by X-ray photoelectron spectroscopy. Journal of Biomedical Materials Research, 52(2), 404-412. doi:10.1002/1097-4636(200011)52:23.0.co;2-zFukuzaki, S., Urano, H., & Nagata, K. (1996). Adsorption of bovine serum albumin onto metal oxide surfaces. Journal of Fermentation and Bioengineering, 81(2), 163-167. doi:10.1016/0922-338x(96)87596-9Malmsten, M. (1998). Formation of Adsorbed Protein Layers. Journal of Colloid and Interface Science, 207(2), 186-199. doi:10.1006/jcis.1998.5763Khan, M. A., Williams, R. L., & Williams, D. F. (1996). In-vitro corrosion and wear of titanium alloys in the biological environment. Biomaterials, 17(22), 2117-2126. doi:10.1016/0142-9612(96)00029-4Kanagaraja, S. (1996). 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A., Vergé, M.-G., & Landolt, D. (2004). EQCM Study of Anodic Film Growth on Valve Metals. Journal of The Electrochemical Society, 151(12), B652. doi:10.1149/1.1819896Schmutz, P., & Landolt, D. (1999). Electrochemical quartz crystal microbalance study of the transient response of passive Fe25Cr alloy. Electrochimica Acta, 45(6), 899-911. doi:10.1016/s0013-4686(99)00293-5Schmutz, P., & Landolt, D. (1999). In-situ microgravimetric studies of passive alloys: potential sweep and potential step experiments with Fe–25Cr and Fe–17Cr–33Mo in acid and alkaline solution. Corrosion Science, 41(11), 2143-2163. doi:10.1016/s0010-938x(99)00038-4Hamm, D., Ogle, K., Olsson, C.-O. ., Weber, S., & Landolt, D. (2002). Passivation of Fe–Cr alloys studied with ICP-AES and EQCM. Corrosion Science, 44(7), 1443-1456. doi:10.1016/s0010-938x(01)00147-0Olsson, C.-O. ., & Landolt, D. (2003). Passive films on stainless steels—chemistry, structure and growth. 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J., & Penn, D. R. (2003). Calculation of electron inelastic mean free paths (IMFPs) VII. Reliability of the TPP-2M IMFP predictive equation. Surface and Interface Analysis, 35(3), 268-275. doi:10.1002/sia.1526Kocijan, A., Milošev, I., & Pihlar, B. (2004). Cobalt-based alloys for orthopaedic applications studied by electrochemical and XPS analysis. Journal of Materials Science: Materials in Medicine, 15(6), 643-650. doi:10.1023/b:jmsm.0000030204.08616.3dHamm, D., Olsson, C.-O. A., & Landolt, D. (2002). Effect of chromium content and sweep rate on passive film growth on iron–chromium alloys studied by EQCM and XPS. Corrosion Science, 44(5), 1009-1025. doi:10.1016/s0010-938x(01)00126-3Schmuki, P. (1996). Transpassive Dissolution of Cr and Sputter-Deposited Cr Oxides Studied by In Situ X-Ray Near-Edge Spectroscopy. Journal of The Electrochemical Society, 143(12), 3997. doi:10.1149/1.1837327Valero Vidal, C., Olmo Juan, A., & Igual Muñoz, A. (2010). 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Stability of 3D-porous Ni/Cu cathodes under real alkaline electrolyzer operating conditions and its effect on catalytic activity

Despite the development and synthesis of new electrode materials for hydrogen generation in alkaline water electrolyzers has been a research topic widely exploited in the last years, stability tests on the obtained cathodes have been restricted to long-term potentiostatic/galvanostatic experiments which do not fulfil the real operating conditions that take place in those devices. In this work, two different Service Life Tests have been designed and implemented, aiming at including particular conditions (i.e. inverse polarity and short-circuit) in the durability and catalytic activity of cathode characterization. For this purpose, Ni/Cu bilayered porous electrodes were prepared using different Ni electrodeposition times (15, 30 and 45 min) following a double template electrochemical method. It has been confirmed that the electrode with the lowest Ni content can be considered as a promising electrocatalyst for hydrogen production under industrial conditions because of its optimal activity and stability after the two sets of testing conditions. In particular, electrochemical studies demonstrated that an inversion in polarity can positively affect the electrode performance, as a consequence of the synergetic interaction between CuO/Cu(OH)(2) and beta-Ni(OH)(2) species formed at potentials below the oxygen evolution domain.The authors gratefully acknowledge financial support given by the Generalitat Valenciana (PROMETEO/2010/023) and Spanish Government (Ministerio de Ciencia e Innovation) for the postgraduate grants AP2007-01243 (Carlos Valero-Vidal) and AP2007-03737 (Isaac Herraiz-Cardona).Valero Vidal, C.; Herraiz Cardona, I.; Pérez-Herranz, V.; Igual Muñoz, AN. (2016). Stability of 3D-porous Ni/Cu cathodes under real alkaline electrolyzer operating conditions and its effect on catalytic activity. Applied Catalysis B: Environmental. 198:142-153. doi:10.1016/j.apcatb.2016.05.030S14215319

Corrosion behaviour of Ti6Al4V ELI nanotubes for biomedical applications

[EN] Surfaces engineering on titanium biomedical alloys aiming for improving bone regeneration, healing periods and increasing lifetime needs fora fundamental understanding of the electrochemical reactions occurring at the interface biomaterial/human fluid. There, electrochemical corrosion plays an important role in implant-tissue interaction. The aim of this study is to investigate the effect of different TiO2 surfaces and nanotubes on a Ti6Al4V ELI in their electrochemical corrosion resistance by different electrochemical techniques (open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization). The electrochemical behaviour of native, anodized, nanotubular and annealed nanotubular surfaces were investigated in 1 M NaCl solution. The nanotubular topography was obtained by electrochemical oxidation and the annealing treatment allowed at changing the crystalline structure of the oxides. The nanotube morphology, chemical composition, and structure was studied by Field Emission Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-ray diffraction and Transmission Electron Microscopy respectively. The results show that the anodic oxidation treatment creates a nanotubular topography that increases the surface area and changes the surface chemical composition. The electrochemical corrosion resistance decreased on the as-formed TiO2 tubes compared to the native oxide layer, due to higher surface area and amorphous crystal structure of the passive film. After annealing treatment, the fluoride ions are eliminated, and nanotubular resistance is enhanced through anatase stabilization.The authors wish to thank the Spanish Ministry of Economy and Competitiveness for the financial support of Research Project MAT2014-53764-C3-1-R, the Generalitat Valenciana for support through PROMETEO 2016/040, and the European Commission via FEDER funds to purchase equipment for research purposes and the Microscopy Service at the Valencia Polytechnic University. Thanks to Alba Dalmau and Javier Navarro Laboulais from Instituto de Seguridad Industrial y Medio Ambiente, Valencia Polytechnic University for the technical assistance with preparation of the electrochemical tests. Thanks to Irene Llorente and Jose Antonio Jimenez from CENIM/CSIC for the technical assistance with XRD characterization.Lario, J.; Viera, M.; Vicente-Escuder, Á.; Igual Muñoz, AN.; Amigó, V. (2019). Corrosion behaviour of Ti6Al4V ELI nanotubes for biomedical applications. Journal of Materials Research and Technology. 8(6):5548-5556. https://doi.org/10.1016/j.jmrt.2019.09.023S554855568

Tribocorrosion behavior of new martensitic stainless steels in sodium chloride solution

The tribo-electrochemical behavior of two new martensitic stainless steels in a 3% NaCI solution has been investigated. Different electrochemical and surface analysis techniques (Scanning Electron Microscopy, Focused Ion Beam) were discussed to analyze the influence of the effect of the electrochemical conditions on friction and wear, and to elucidate involved wear mechanisms (plastic deformation, plastic shakedown and low-cycle fatigue). The selected stainless steels degrade through a delamination type of wear mechanism. The effects of the applied potential on wear are related to the formation of a passive film which alters the mechanical behavior of the surface and subsurface of the materials to promote wear. A coefficient of friction below 0.6 promotes nanowear, and a transition was observed when the coefficient of friction exceeded that value. (C) 2016 Elsevier B.V. All rights reserved.The authors would like to thank to BPI, Region Centre and Tours Plus for support of this research. This work is done under the project FUI 11 Mekinox.Dalmau Borrás, A.; Rmili, W.; Richard, C.; Igual Muñoz, AN. (2016). Tribocorrosion behavior of new martensitic stainless steels in sodium chloride solution. Wear. 368:146-155. doi:10.1016/j.wear.2016.09.002S14615536

Wear model for describing the time dependence of the material degradation mechanisms of the AISI 316L in a NaCl solution

[EN] The tribo-electrochemical behavior of AISI 316L has been investigated under tribocorrosion conditions in a 3% NaCl solution and the material damage evolution with time has been analyzed. A numerical contact model based on a Boundary Element Method (BEM) has been developed in order to determine the contact pressure distribution and to quantify the worn material as a function of time. The time dependence of the tribological behavior of the material has been described. At the initial state, the high contact pressures generate a material flow causing an increase in the worn area. After around 300 cycles, the Archard wear model linearly describes the wear evolution with time. The proposed model describes the evolution with time of the wear profiles of the tested material and takes into account the plastic behavior of the material during the first cycles.This work has been funded by the Spanish Ministry of Economy and Competitiveness under the Ref. MAT2014-53764-C3-3-R and the Generalitat Valenciana under the PROMETEO program Ref. 2016/040.Dalmau-Borrás, A.; Roda Buch, A.; Rovira, A.; Navarro-Laboulais, J.; Igual Muñoz, AN. (2018). Wear model for describing the time dependence of the material degradation mechanisms of the AISI 316L in a NaCl solution. Wear. 394-395:166-175. https://doi.org/10.1016/j.wear.2017.10.015S166175394-39

Chemo-mechanical effects on the tribocorrosion behavior of titanium/ceramic dental implant pairs in artificial saliva

[EN] In this paper, the degradation mechanisms of the ceramic and the metal in Titanium/Zirconia pairs for biomedical applications were analyzed. To do that, an experimental set-up with well-controlled mechanical and chemical conditions was used based on a unidirectional ball-on-disk tribometer coupled to a potentiostat. Tribocorrosion tests were carried out in artificial saliva at different applied potentials, this is, different chemical conditions of the surface. Wear damage of the titanium/zirconia pair was influenced by the properties and the behavior of wear debris in the contact. Under passive conditions metallic and oxidized titanium particles (formed by the cyclic removal of the passive film and subsequent repassivation) were smeared and mechanically mixed within the contact forming compacted wear debris through which the loading was carried out. Properties and amount of oxidized titanium lead to low wear at low passive conditions (OCP) and higher wear at high passive conditions. Zirconia did not suffer any damage under all the studied conditions and oxidized titanium was transferred to the ball at anodic applied potentials.Authors would like to acknowledge the Generalitat Valenciana for the financial support under the PROMETEO/2016/040 and GV/2017/042 projects. A. Dalmau acknowledges the Generalitat Valenciana for her contract (APOSTD/2017/051).Dalmau-Borrás, A.; Roda Buch, A.; Rovira, A.; Navarro-Laboulais, J.; Igual Muñoz, AN. (2019). Chemo-mechanical effects on the tribocorrosion behavior of titanium/ceramic dental implant pairs in artificial saliva. Wear. 426-427:162-170. https://doi.org/10.1016/j.wear.2018.12.052162170426-42

Wear of CoCrMo alloys used in metal-on-metal hip joints: A tribocorrosion appraisal

A good biocompatibility, excellent mechanical properties and high corrosion resistance characterize CoCrMo alloys. Therefore they are widely used for artificial joints in biomedical implants. However, the degradation of the implants during service life leads to the release into the body of toxic ions and wear particles. This continuous degradation is of concern for long-term stability of the implants. Published literature has highlighted the relevance of lubrication as well as metallurgical and contact mechanical factors on the degradation of CoCrMo implant alloys. Recent experimental investigations have proposed tribocorrosion, i.e., the interplay of mechanical wear and corrosion by the body fluids, as one of the crucial degradation mechanism of implants. Tribocorrosion is sub-discipline of tribology and corrosion that recently made significant progresses in mechanistic understanding and modelling. The present work aims at evaluating published results on the degradation of CoCrMo alloys using existing tribocorrosion concepts. Results show that wear accelerated corrosion due to mechanical removal of the passive film during sliding is a major contribution to the overall degradation. Further, a transition from low (10(-6) N/mm(3) m) to high (10(-4) N/mm(3) m) wear coefficients was found at a threshold electrode potential close to 0.2 V-SHE These findings clearly show that electrochemical phenomena play a key role on the tribological behaviour of biomedical CoCrMo alloy implants.A. Igual Munoz expresses her gratitude to the Ministerio de Ciencia e Innovacion of the Spanish government for the financial support under the project MAT2011-22481.Mischler, S.; Igual Muñoz, AN. (2013). Wear of CoCrMo alloys used in metal-on-metal hip joints: A tribocorrosion appraisal. Wear. 297(1-2):1081-1094. https://doi.org/10.1016/j.wear.2012.11.061S108110942971-