Selective electron beam melting of WMoTaNbVFeCoCrNi refractory high-entropy alloy

FeCoCrNi- and WMoTaNb-based alloys are two prevalent high-entropy alloy systems. Owing to the great differences between these two alloy systems, researches were carried out on the FeCoCrNi- or WMoTaNb-based alloys fabricated by traditional methods, such as cast and sparking plasma sintering. Recently, additive manufacturing is widely employed in forming FeCoCrNi- and WMoTaNb-based alloys due to its superiority of complex shape forming and flexible materials design, which can intensively meet the requirements in the coming divergent demands for refractory alloy. In present study, WMoTaNbV alloying powder was physically mixed with FeCoCrNi alloying powder and the final mixture was additively manufactured by selective electron beam melting. The as-deposited WMoTaNbVFeCoCrNi RHEA exhibits significant elemental segregation and consists of multiple phases, including body-centered cubic (BCC), face-centered cubic (FCC), and Laves phases. Because of the secondary phase strengthening and microstructure refinement strengthening as well as solid solute strengthening, the as-deposited WMoTaNbVFeCoCrNi RHEA has an outstanding Vickers hardness of 836 ± 17 HV at least and a compressive yield strength of 915 ± 47 MPa at 1200 °C.