The effect of surface treatments on the fretting behavior of Ti‐6Al‐4V alloy

Abstract

Stem modularity in total hip replacement introduces an additional taper joint between Ti-6Al-4V stem components with the potential for fretting corrosion processes. One possible way to reduce the susceptibility of the Ti-6Al-4V/Ti-6Al-4V interface to fretting is the surface modification of the Ti-6Al-4V alloy. Among the tested, industrially available surface treatments, a combination of two deep anodic spark deposition treatments followed by barrel polishing resulted in a four times lower material release with respect to untreated, machined fretting pad surfaces. The fretting release has been quantified by means of radiotracers introduced in the alloy surface by proton irradiation. In a simple sphere on flat geometry, the semispherical fretting pads were pressed against flat, dog-bone shaped Ti-6Al-4V fatigue samples cyclically loaded at 4 Hz. In this way a cyclic displacement amplitude along the surfaces of 20 mum has been achieved. A further simplification consisted in the use of deionized water as lubricant. A comparison of the radiotracer results with an electrochemical material characterization after selected treatments by potentiostatic tests of modular stems in 0.9% NaCl at 40 degrees C for 10 days confirmed the benefit of deep anodic spark deposition and subsequent barrel polishing for improving the fretting behavior of Ti-6Al-4V.

Application-wise nanostructuring of anodic films on titanium: a review

“…Silicate and silicateÀaluminate solutions are among the most used electrolytes employed to generate ceramic coatings that improve the tribocorrosion behaviour of TiAl alloys. [102,103] Coating effectiveness can be related to the incorporation of silicates in the ceramic coating, either increasing surface hardness or reducing its friction coefficient, [24,104,105] and consequently the adhesion between the component surface and counterpart, thus limiting wear and debris generation. One example of ASD coating produced on mechanical components (planar specimens as well as complex 3D geometries) is shown in Figure 10, where the oxide thickness and morphological features due to spark anodising (microcracks, craters) are highlighted.…”

Anodic oxidation of titanium: from technical aspects to biomedical applications

“…None of the authors have any financial interest in the materials or equipment reported in this study or in the companies that produce them. In this case, the ionic release was investigated to assess the resistance of the surface to fretting corrosion, and the ASD coatings were proven to increase the performances of the coated materials, as attested by both fretting release experiments and more classic electrochemical tests (potentiostatic or potentiodynamic tests), which present less operative complexity but lower adherence with the final behavior of the material in its service life (157)(158)(159)(160).…”

EFEITO DAS CONDIÇÕES DE ANODIZAÇÃO EM Ti6Al4V NAS CARACTERÍSTICAS DO ÓXIDO FORMADO

“…Um dos tratamentos de superfície mais recomendados e versáteis é o processo de oxidação anódica do titânio, já que é capaz de alterar as características superficiais da camada de óxido formada, as quais incluem espessura, densidade, cor, homogeneidade, morfologia, rugosidade, composição química, reatividade, cristalinidade, dentre outras (Dalmiglio et al, 2008;Diamanti e Pedeferri, 2007;Fan et al, 2012;Fazel et al, 2015;Kumar et al, 2010;Lee et al, 2010;Liu et al, 2004;Park et al, 2006;Shabani et al, 2015;Szewczenko et al, 2010;Visai et al, 2008). Essas características são fortemente influenciadas pela temperatura, pH, composição, concentração do eletrólito e por parâmetros eletroquímicos, tais como densidade de corrente e potencial aplicados (Diamanti e Pedeferri, 2007;Diamanti et al, 2011;Fan et al, 2012;Lee et al, 2010;Park et al, 2006;Simka et al, 2011;Vanhumbeeck e Proost, 2009;Walsh et al, 2009).…”

“…Resultados publicados evidenciam que esse método eletroquímico possibilitou relevante melhoria na biocompatibilidade e na resistência à corrosão de implantes de ligas de titânio, produzindo filmes de dióxido de titânio uniformes, porosos, aderentes, relativamente espessos e mais cristalinos (Dalmiglio et al, 2008;Fazel et al, 2015;Giordano et al, 2011;Kumar et al, 2010;Narayanan e Seshadri, 2008;Pan et al, 2013;Sandrini et al, 2003;Shabani et al, 2015;Szewczenko et al, 2010). O dióxido de titânio obtido por oxidação anódica se apresenta sob duas formas: cristalina e amorfa.…”