Synergistic effects of WC nanoparticles and MC nanoprecipitates on the mechanical and tribological properties of Fe<inf>40</inf>Mn<inf>40</inf>Cr<inf>10</inf>Co<inf>10</inf> medium-entropy alloy

Abstract

The synthesis of Fe40Mn40Cr10Co10/WC composites by a combination of ball milling and spark plasma sintering is reported and corresponding mechanical and tribological properties of these composites are investigated. Compared with the Fe40Mn40Cr10Co10 MEA (medium entropy alloy), the addition of 10 vol.% WC nanoparticles led to an increase in the compressive strength and hardness from 1.571 GPa and 320 HV to 2.324 GPa and 788 HV, respectively. Meanwhile, tribological tests demonstrated that the friction coefficient, wear depth and width of the composite decreased in comparison with Fe40Mn40Cr10Co10 MEA. Load transfer effect, thermal mismatch mechanism, Orowan strengthening and grain refinement resulting from synergistic effects between ex-situ WC nanoparticles and in-situ M23C6 nanoprecipitates are responsible for the improvement in mechanical properties, especially thermal mismatch mechanism and grain refinement. In addition, the enhancement in tribological properties is also ascribed to these synergistic effects.