Passivation and mechanical property improvement of Co-Cr-Mo alloy

The surfaces of Co-Cr-Mo alloy were modified by high temperature passivation. The impact of the passivation temperature on the microstructures and mechanical properties of the Co-Cr-Mo alloy was investigated. The passivated alloy was characterized with X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and conventional mechanical probes. The tribological properties of the modified surfaces in bovine serum albumin solution were evaluated with standard tribometer. The results show that the passivation increased the hardness, roughness, and wear assistance, but decreased the friction coefficient of the modified Co-Cr-Mo alloy surfaces synthesized with spinal like Cr₂O₃ grains. As the passivation temperature rose up, the thickness, hardness and roughness of the passivated surfaces increased. The morphology of wear track depends strongly on the surface roughness and interface adhesion.