Ductile W0.4MoNbxTaTi refractory high-entropy alloys with excellent elevated temperature strength

Abstract

In order to obtain refractory alloys with both high strength and good ductility simultaneously, the novel W0.4MoNbxTaTi high entropy alloys were developed, of which the crystal structure, microstructure, and compression properties were investigated as well. The as-cast alloys had a single BCC phase structure with dendritic substructure in coarse polygon crystal grains. The alloys exhibited outstanding mechanical properties at testing temperatures. The optimal yield strength and fracture strain were 1334 MPa and 38.9% in W0.4MoNb1.3TaTi alloy at ambient temperature. Furthermore, its yield strength decreased to 1125, 905, and 425 MPa at 1073, 1273, and 1373 K, respectively. And it showed high specific yield strength at elevated temperature. The compression performances of the W0.4MoNb1.3TaTi alloy were superior in comparison with other refractory high entropy alloys.