High-temperature oxidation resistance, mechanical and wear resistance properties of Ti(C,N)-based cermets with Al0.3CoCrFeNi high-entropy alloy as a metal binder

Abstract

Al0.3CoCrFeNi high-entropy alloy (HEA) prepared by mechanical alloying was used as a metal binder for the Ti(C,N)-based cermets by hot-pressing sintering. Room-temperature microstructure and high-temperature oxidation resistance, mechanical and wear resistance properties of the Ti(C,N)-based cermets with HEA metal binder (cermets TA) were comprehensively investigated and compared with the Ti(C,N)-based cermets containing the conventional Ni–Co metal binder (cermets TN). Different from the Ni–Co binder, the HEA metal binder not only largely enhanced the hardness and fracture toughness of Ti(C,N)-based cermets at room temperature, but also retained notably higher hardness (Vickers hardness 1137 HV), fracture toughness (6.46 MPa m1/2) and flexural strength (761 MPa) at 1000 °C. The mechanism for such an excellent retention of mechanical properties at high-temperature by the cermets TA is attributed to the hindrance of their slip systems and the higher oxidation resistance of HEA metal binder. Furthermore, the hardened cermets TA exhibited better friction and wearing properties at high-temperature.