Enhancement of mechanical and tribological performance of Ti–6Al–4V alloy by laser surface alloying with Inconel 625 and SiC precursor materials

Abstract

This study focused on producing metal matrix composite (MMC) coatings on Ti–6Al–4V alloy through laser surface alloying using a novel combination of Inconel 625 and SiC precursor materials. Various ratios of alloying powders were examined to evaluate surface properties such as microhardness, wear resistance, and friction coefficient, along with analyzing the phase composition and microstructure of the coatings. The in situ synthesized MMC coatings exhibited the presence of α-Ti, NiTi, NiTi₂, and TiC phases. Additionally, Ti₅Si₃ and α-Ti/Ti₅Si₃ eutectic structures were observed when the SiC content exceeded 20%. In comparison to the titanium substrate, the MMC coating significantly enhanced microhardness by over threefold and reduced wear by 95%. However, it was crucial to carefully select the appropriate combination of alloying powders to avoid a substantial decrease in friction performance and excessive formation of cracks. Through a comparative analysis of experimental results, the optimal precursor material composition was identified as 85% Inconel 625 and 15% SiC. This study demonstrated the effective utilization of Inconel 625 and SiC alloying materials to enhance the surface properties of titanium alloys, thereby expanding their application in challenging environments.