Microstructure and wear resistance of laser clad Ti₅Si₃/NiTi₂ intermetallic composite coating on titanium alloy

A wear resistant Ti₅Si₃/NiTi₂ intermetallic composite coating was fabricated on substrate of a titanium alloy BT9 by laser cladding with (wt.%) Ni-30Ti-10Si elemental powder blends. The laser clad intermetallic composite coating has a rapidly solidified fine microstructure consisting of Ti₅Si₃ primary particles uniformly distributed in the NiTi₂ matrix and is metallurgically bonded to the titanium substrate. The laser clad Ti₅Si₃/NiTi₂ intermetallic composite coating has high hardness and excellent wear resistance under dry sliding wear test conditions. The excellent wear resistance of the laser clad Ti₅Si₃/NiTi₂ intermetallic composite coating is attributed to the coating's high hardness, strong intermetallic atomic bonding and refined microstructure.