Tribological performances of CoCrFeNiAl high entropy alloy matrix solid-lubricating composites over a wide temperature range

Abstract The reliable operation of advanced industrial tribo-systems depends on solid-lubricating composites with excellent tribological performances over a wide temperature range. Here, we introduce the CoCrFeNiAl high-entropy alloy matrix solid-lubricating composites that exhibit outstanding wear-resistant and friction-reduced properties at temperature from room temperature to 800 °C. The formation of lamellar h-BN and Ag tribo-film inhibits the three-body abrasion and oxidative wear of the frictional interface below 600 °C, so that both the coefficient of friction and the wear of the composites are low. At 600 °C, high temperature softening of the composites increases its wear. At 800 °C, a protective oxide layer form on the worn surface of the composites, contributing to the low wear.