Effect of synovial fluid temperature on the corrosion resistance of Ti6Al4V, Ti6Al7Nb, and CoCrMo alloys

Abstract

The frictional heat generated during the operation of the joint prosthesis in vivo could change the corrosion resistance of the prosthesis material. In this paper, the corrosion behavior of three medical alloys at different synovial fluid temperatures was analyzed using electrochemical measurement technology. Furthermore, the scanning electron microscope and energy‐dispersive spectrometer were used to characterize the surface morphology and composition of the alloys after long‐term immersion. The results show that increasing temperature causes the open‐circuit potential of titanium alloy to shift negatively and the corrosion tendency to increase. The increasing temperature leads to the decrease of activation energy of titanium alloy, which in turn results in the increase of corrosion current density and accelerated corrosion. The results of Nyquist curves confirmed that the radius of the capacitive arc decreased with the increase of temperature, indicating the deterioration of corrosion resistance. The CoCrMo alloy shows the same regularity as the titanium alloy in 0.9% NaCl, though no obvious regularity in 25% newborn bovine serum; this may be related to the complexity of the corrosion system.

Comparative analysis of the surface properties and corrosion resistance of Co-Cr dental alloys fabricated by different methods

“…A positive correlation has been reported between the radius of the capacitive reactance arc in the Nyquist diagram and the R ct value of the investigated electrode. 27 Figure 6B shows that all specimens had similar arc shapes, suggesting that the corrosion mechanism was similar, while the SLM and CNC groups exhibited a larger arc than the CAST group. With the method of fitting, the R ct values in descending order were SLM (250.06 ±37.40 kU•cm 2 ), CNC (128.70 ±32.26 kU•cm 2 ), and CAST (54.70 ±14.60 kU•cm 2 ).…”

Research progress on the oxidation behavior mechanism and the design of antioxidant methods of artificial polymer acetabular cup

“…Research has demonstrated that in vivo service of hip prostheses results in higher frictional heat generation at the contact interface compared to natural joints. [33][34][35][36] The temperature rise has a considerable impact on the oxidative behavior of the polymer materials. 37,38 Usually, plastic deformation and severe adhesion of UHMWPE will occur above 50 C. With the increase of temperatures, hardness and wear resistance of UHMWPE register a marked reduction, and the wear resistance diminishes faster than the hardness.…”

“…Research has demonstrated that in vivo service of hip prostheses results in higher frictional heat generation at the contact interface compared to natural joints 33–36 . The temperature rise has a considerable impact on the oxidative behavior of the polymer materials 37,38 .…”

In vitro corrosion response of CoCrMo and Ti-6Al-4V orthopedic implants with Zr columnar thin films

“…281 and 84 μm/yr, respectively. This can be explained by the higher passivation ability of the Ti-6Al-4V, leading to the formation of a protective oxide layer at the surface of the sample [55][56][57]. Zirconium, as a transition metal, presents also a passivation behavior [58,59] and protects the substrates thanks to a lower OCP.…”