Design of VNbTaMo_x Body-Centered-Cubic Refractory High-Entropy Alloys with Excellent Ultrahigh-Temperature Mechanical Properties and Ductility

To design metal materials that combine high-temperature strength with room-temperature ductility, three kinds of body-centered-cubic (BCC) refractory high-entropy alloys (RHEAs) with different Mo element contents are screened and prepared by combining several parameters. The room-temperature ductility and excellent high-temperature (1500 °C) mechanical properties are investigated. Combined with the microstructure test, the characteristic of fracture and deformation is also discussed. RHEAs studied herein have great compressive yield strength approximately ranging from 1324.5 to 1424.4 MPa with excellent compressive ductility ranging from 20.7% to 44.2% at room temperature. At 1500 °C, the yield strengths of three RHEAs are over 335.47 MPa at 10⁻³ s⁻¹ strain rate, which is rarely found in traditional metals materials. The excellent mechanical properties of these three RHEAs at both room and high temperature as a promising material are beneficial to future high-temperature application.