Sliding Corrosion Fatigue of Metallic Joint Implants: A Comparative Study of CoCrMo and Ti6Al4V in Simulated Synovial Environments

Abstract

Mechanical contact in a corrosive synovial environment leads to progressive surface damage at the modular interface of the joint implants. The wear debris and corrosion products degrade the synovial fluids and change the lubrication mechanisms at the joints. Consequently, the unstable joint lubrication and corrosion products will further induce the undesirable performance of the joint implants. In this study, the two major joint materials, CoCrMo and Ti6Al4V, were tested during the course of reciprocal sliding contact in simulated synovial liquids. Open circuit potential and coefficient of friction were monitored to describe electrochemical and mechanical responses. Potentiostatic test results illustrated electrochemical damage on both surfaces that modified oxidation chemistry on both surfaces. However, more significant modification of the CoCrMo surface was detected during wear in the simulated joint liquid. Even with a reduced coefficient of friction on the CoCrMo surface in sodium lactate environments, fretting current density drastically increased in corrosive sodium lactate with pH 2. However, the test results from the Ti6Al4V surface presented less coefficient of friction values, and moderate change in fretting current. Therefore, the experimental study concluded that the biocompatibility of Ti6Al4V is superior to that of CoCrMo in the combined effect of mechanical loadings and an electrochemical environment.

In Silico Contact Pressure of Metal-on-Metal Total Hip Implant with Different Materials Subjected to Gait Loading

“…To solve this problem, the proper selection of the metal material needs to be evaluated further due to concerns regarding biological problems to minimize failures that occur. Metal materials commonly used as bearing materials include cobalt chromium molybdenum (CoCrMo) [15], stainless steel 316 L (SS 316L) [16], and titanium alloy (Ti6Al4V) [17]. In the development of implants that are suitable for the Indonesian population and most countries in Asia as developing countries, apart from looking at the material aspect, the size of the implant also needs to be considered.…”

Scratch and Wear Behaviour of Co-Cr-Mo Alloy in Ringer’s Lactate Solution

“…Adhesion wear occurs when two surfaces are pressed together under load, with the transfer of material from one surface to the other [ 32 ]. The metallic surface of the implant reacts with the air environment, forming a passive layer that acts as a barrier, separating the metal from the aggressive environment [ 33 ]. However, when in contact with the body fluids, this layer may be removed by corrosion or tribocorrosion, which can lead to the release of particles from the material [ 34 , 35 ].…”