Tribological behavior of Ti(C, N)-TiB2 composite cermets using FeCoCrNiAl high entropy alloys as binder over a wide range of temperatures

Abstract Ti(C, N)-TiB2 composite cermets with different binders (high entropy alloy (HEA) or Ni-Co) were fabricated by mechanical alloying and vacuum hot-pressing sintering. The wear resistance of the two composite cermets at elevated temperatures was studied. Wear mechanism was characterized by a combination of scanning electron microscopy and energy dispersive spectroscopy. The experimental results indicated that HEA binder composite cermets possessed excellent wear resistance comparing with Ni-Co binder composite cermets. At lower temperatures, no obvious difference was observed in the worn surfaces of two cermets. Abrasive wear mechanism was dominant wear mechanism. At greater than 600 °C, oxidative wear and adhesive wear were found to be dominant wear mechanism. The wear rate of the HEA binder composite cermets was 11.8 %, 17 %, 39.25 %, and 46.7 % lower than that of the Ni-Co binder composite cermets at 200 ℃, 400 ℃, 600 ℃, and 800 ℃, respectively. The enhanced wear performance of Ti(C, N)-TiB2-HEA composite cermets is attributed to relatively high hardness and toughness, as well as excellent high-temperature softening resistance and oxidation resistance of HEA.