Effects of C and heat treatment on microstructure, mechanical, and tribo-corrosion properties of VAlTiMoSi high-entropy alloy coating

Abstract

High-entropy alloy (HEA) coatings have demonstrated great potential in anti-wear applications. To further improve the mechanical and tribo-corrosion properties of the HEA coatings, the VAlTiMoSi, (VAlTiMoSi)80C20, and (VAlTiMoSi)60C40 coatings were successfully deposited by DC magnetron sputtering. The microstructure, mechanical, and tribo-corrosion properties of as-deposited and heat-treated coatings were analyzed. All the as-deposited HEA coatings were BCC + amorphous phases. The thermal effect promoted the formation of intermetallic compounds, and the C inhibited the formation of Mo3Si and Ti5Si4. The hardness and elastic modulus of the heat-treated VAlTiMoSi coating were 20.1 and 294.0 GPa, respectively. The heat-treated (VAlTiMoSi)60C40 coating showed the lowest wear rate, namely 5.2 × 10−14 m3·Nm−1, and the best formation ability of passive film in 3.5 wt% NaCl solution.

Keywords

• high-entropy carbides
• mechanical performance
• wear resistance
• heat treatment
• magnetron sputtering