Investigations on Surface Integrity and Electrochemical Behavior of Machined Co-Cr-Mo Bio-implant Alloy

Abstract

A decisive constraint for the long-term stability of the artificial joint is to minimize the release of debris particles. The wear/debris induced osteolysis and aseptic loosening are the result of failure of metal-on-metal joint implants. SPD processes have been used to adapt the surface integrity properties by generating ultrafine or even nano-sized grains and grain size gradients in the surface region of work materials. These fine grained materials often show enhanced surface integrity properties and improved functional performance (wear resistance, corrosion resistance, fatigue life, etc.) compared with their predictable coarse grained counterparts. To identify the implant material's post machined behaviour in biological environment, the experiments were planned by precision CNC turning process and accordingly post machined surfaces were analyzed by contact type and electrochemical measurement processes. The work includes effect of machining parameters on machined surface roughness and corrosion rate by an electrochemistry of Co-Cr-Mo bio-implant alloy. The minimum machined surface roughness value 0.450 µm shows minimum corrosion rate as 0.00002 mm/year. It is also shown that feed rate is having predominating effect on machined surface roughness and rake angle is on corrosion rate of Co-Cr-Mo bio-implant alloy.