Ti-Si coating by laser alloying on TC4 titanium alloy

Abstract:

Using Ti and Si elemental elements mixed powder as raw material, Ti-Si alloy coating was successfully fabricated on the surface of titanium alloy by laser alloying. Microstructure morphology, composition and phase of the coating were investigated. Microhardness and tribological properties under dry friction and wear conditions were tested. The results show that: the Ti-Si coating under the appropriate parameters of laser alloying prepared is uniform and dense, crack-free, and combined with a generally good metallurgical TC4 base; coating microstructure is consisted of needle-like α-Ti matrix and network distribution of Ti5Si3/β-Ti eutectic (room temperature is Ti5Si3/α-Ti) composition; the hardness of the coating is between HV 660 ~730;compared with TC4 titanium alloy, the average friction coefficient decreases (0.39VS0.45) and wear resistance increased 2.4 times.

Key words:TC4 titanium alloy;laser alloying;Ti-Si alloy;microstructure;wear resistance