Microstructure, mechanical and tribological properties of CoCrFeNi high-entropy alloy fabricated by different preparing processes

The corresponding performance of CoCrFeNi high-entropy alloy (HEA) under different preparing processes can meet the different engineering application requirement. The microstructure, mechanical and tribological properties of CoCrFeNi HEA fabricated by melting-casting (MC), thermomechanical treatment (TMT) and selective laser melting (SLM) are systematically investigated in this work. The results indicate the optimal strength-ductility synergy and wear ability in as-TMTed sample with fine grains decorated with profuse twins. The excellent ductility (75 %) in as-MCed sample with coarse grains while the superior yield strength (472.27 MPa) in as-SLMed sample with nanosized cellular substructure are confirmed. The micropores in as-SLMed sample lead to the poor tribological performance.