Laser Surface Modification of Ti-6Al-4V Alloy with Silicon Carbide

We show that surface laser modification through a coating containing SiC powder is an efficient method for enhancing the wear resistance of Ti-6Al-4V titanium alloy. The laser melting of SiC particles enriches the pool of substrate melt with silicon and carbon. In the course of crystallization, primary dendrites, which are identified as TiC, are formed at first. After fast cooling to room temperature, a multiphase structure consisting of Ti5Si3 and TiSi2 silicides and ductile α″-martensite is formed in the interdendritic space. Such a composite structure of the surface layer has a microhardness of 5–6 GPa and guarantees a sharp enhancement of the wear resistance under conditions of dry sliding friction as compared with the hardened-and-aged structure of this alloy.