Effect of Carbon and Heat Treatment on the Microstructure and Properties of VAlTiCrSi High-Entropy Alloy Films

The VAlTiCrSi, (VAlTiCrSi)(90)C-10 and (VAlTiCrSi)(80)C-20 (atomic percent) high-entropy alloy films were deposited by magnetron sputtering, and the effects of various C contents and heat treatment at 700 degrees C on the microstructure, mechanical properties and tribo-corrosion properties of as-deposited films were studied systematically. For the as-prepared films, the amorphous structure was found in the VAlTiCrSi film and its corresponding carbon-doped films. And, (VAlTiCrSi)(80)C-20 film had the highest hardness of 13.58 GPa and the lowest wear rate of 7 x 10(-5) mm(3)/Nm due to the solid solution strengthening effect of C. After annealing, the microstructure of VAlTiCrSi, (VAlTiCrSi)(90)C-10 and (VAlTiCrSi)(80)C-20 high-entropy alloy films changed from amorphous structure to crystalline state and formed a small amount of carbide phase. The hardness and wear rate of (VAlTiCrSi)(80)C-20 film were significantly increased to 1.7 times and decreased to 3.6 times the as-deposited (VAlTiCrSi)(80)C-20 film, respectively.