Powder Metallurgy Fabrication and Microstructure-Mechanical Property Tailoring of V_0.6CrNbMoW Refractory High-Entropy Alloy

Refractory high-entropy alloys possess exceptional high-temperature mechanical properties and thermal stability, demonstrating broad application prospects in fields such as aerospace and nuclear energy engineering. In this work, V_0.6CrNbMoW refractory high-entropy alloys were prepared by mechanical alloying combined with spark plasma sintering. The influence of ball milling time on the alloying behavior of the powders was systematically investigated, together with the regulation by sintering temperature (1300~1500 °C) of the microstructure and mechanical properties of the bulk alloy. The results show that during the mechanical alloying process, the powders experience three stages successively: agglomeration, refinement, and compositional homogenization, ultimately producing alloy powders with an average particle size of ca. 2 μm and a single body-centered cubic (BCC) phase. After sintering, the alloy microstructure mainly consists of the BCC phase, Laves phase, and trace oxides. As the sintering temperature rises, the densification degree and mechanical properties of the alloy follow a trend of initially increasing and then decreasing. At 1400 °C, the alloy exhibits the optimal comprehensive performance: a density of 10.40 g/cm³, compressive strength of 3174 MPa, yield strength of 3015 MPa, plastic strain of 15.2%, and microhardness of 874HV.