Microstructure and property of laser metal deposition composite coating on Ti6Al4V alloy surface

Wear-resistant composite coatings were fabricated on substrate of a titanium alloy Ti6Al4V by laser metal deposition (LMD) process using Cr2C3, WC and Ti powders in order to enhance the tribological properties of Ti6Al4V. The microstructure of the coatings was characterized and the coating microhardness was tested. And their wear resistance was evaluated under room-temperature dry-sliding wear test conditions. The results show that the two kinds composite coatings have fine microstructure consisting of in-situ TiC particles and the unmelted WC particles uniformly distributed in the matrix and are metallurgically bonded to the titanium substrate. The coatings exhibit excellent wear resistance due to the rapidly solidified fine microstructure and the presence of a large amount of in-situ TiC and WC phase. The coating with TiC reinforced phase has better hardness gradient and slightly lower wear resistance than the coating with WC particles.