Anti-friction and anti-infection properties on biomedical Ti3Zr2Sn3Mo25Nb alloy driven by high-precision cross-elliptical micro-texture and copper coating

Abstract

A surface modification method was proposed to boost tribological properties of near β-type biomedical titanium alloy Ti3Zr2Sn3Mo25Nb (TLM) by synergistic application of micro-texture and copper coating. In calf serum, the friction coefficient on the TLM surface decreased by approximately 17% when the micro-texture density was 15%. Furthermore, the texture-free modified TLM surface exhibited reduced friction coefficients under various loads, with a maximum decrease of nearly 30%. Additionally, the wear mass and wear rate of TLM surface were as low as 1.97 times and 2.34 times of commercial Ti6Al4V alloy when combining micro-texture with copper coating, respectively. The anti-friction mechanism can be attributed to enhanced load-bearing capacity due to micro-texture and the self-lubricating effect by copper coating. Importantly, introducing copper coating on micro-textured surface will catalyze protein denaturation to generate graphite-like carbon films during friction with an anti-friction property, meanwhile, exhibited significant antibacterial activity, with the antibacterial rate of 99.41% and 94.70% against Staphylococcus aureus and Escherichia coli, effectively improving postoperative infections.