High-temperature wear properties of CrFeHfMnTiTaV septenary complex concentrated alloy film produced by magnetron sputtering

Abstract

Entropy stabilized multicomponent alloys offer remarkable mechanical properties and thermal stability rendering these alloys for high-temperature protective films. A novel septenary CrMnFeHfTiTaV complex concentrated alloy (CCA) film was deposited using magnetron sputtering on 304 stainless steel (SS) and silicon substrates. The phase evolution, nano hardness, and tribological behavior of the film were investigated. The as-deposited CCA film displayed a stable amorphous phase up to 600 °C. The indentation hardness of the CCA film was 6.9 GPa compared to 3.3 GPa of the 304 SS substrate. The ball-on-disc wear tests showed that the coefficient of friction (COF) of 304 SS substrate increased from 0.40 at room temperature to 0.46 at 300 °C, whereas for the CCA film, it decreased from 0.82 to 0.44 due to the formation of a lubricating oxide layer. The COF of the 304 SS and the CCA film was similar at 500 °C, however, the wear rate on the CCA film was 7.9 × 10−5 mm3 N−1 m−1 and on the 304 SS was 158.6 × 10−5 mm3 N−1 m−1. The septenary CrMnFeHfTiTaV complex concentrated alloy films offered a robust technology to increase the surface properties of 304 SS and provide wear protection from oxide ceramics such as Al2O3 counter face from RT to 500 °C.