Effects of phase transition on tribological properties of amorphous VAlTiCrSi high-entropy alloy film by magnetron sputtering

High-entropy alloy films have shown great potential in high-temperature antifriction and anti-wear applications. Magnetron sputtering high-entropy alloy films with uniform composition will have inevitable structural changes at high temperatures, which have an impact on their tribological behavior. In this work, amorphous VAlTiCrSi high-entropy alloy films prepared by magnetron sputtering show good thermal stability and high-temperature tribological properties. Especially at 700 °C, the structural change from an amorphous phase to a mixture consisting of body-centered cubic, Al8Cr5, (V, Ti, Cr)5Si3, and amorphous phases are responsible for the improved tribological properties. The hard body-centered cubic phase with solid-solution strengthening effect and intermetallic compounds significantly enhance the mechanical properties of VAlTiCrSi film, so as to improve the wear resistance performance of the films. The insight into the relationship between structural changes and friction properties will contribute to the design of novel high-performance high-entropy alloy films in high-temperature environments.