Effect of heat treatment on wear resistance of cold-sprayed Ti-diamond composite coating

In order to enhance the wear resistance of cold-sprayed Ti coatings, Ti-diamond (Ti-MD) composite coatings were fabricated, followed by heat treatment at different temperatures. The effects of heat treatment temperature on the wear resistance of the composite coatings were assessed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), microhardness testing, and wear resistance experiments. The results show that the composite coating undergo no phase transformation after heat treatment, and exhibits higher microhardness and improved wear resistance. The porosity results showed that the porosity of the coating decreased as the heat treatment temperature increases. TEM results showed that stable TiC (about 10 nm) was formed at the interface between the titanium and diamond particles after heat treatment at 800 °C, and nanoindentation results showed that the heat-treated coating had higher deformation resistance. Specifically, when the heat-treated temperature rose to 800 °C, the composite coating exhibits an 80 % reduction in wear rate, primarily attributable to the decreased porosity of the coating and the enhanced adhesion between Ti and diamond particles. The wear mechanisms of the heat-treated coatings are predominantly reduced oxidative and abrasive wear.