Preparation and Characterization of Multiphase W x Ti x MoNbTaV Refractory High‐Entropy Alloys

Refractory high‐entropy alloys (RHEAs) have emerged as promising materials. They offer a viable alternative to nickel‐based superalloys due to their excellent mechanical property stability at high temperatures, superior oxidation and corrosion resistance, and phase stability under extreme conditions. In this study, three different RHEA compositions of W x Ti x MoNbTaV RHEAs ( x 1 = (1, 0), x 2 = (0, 1), and x 3 = (0.5, 0.5)) were synthesized by partially or fully substituting titanium for tungsten under identical conditions to investigate the effect of this modification on the microstructure. Mechanical alloying was performed for 60 h to obtain powders with a single‐phase BCC structure, followed by spark plasma sintering (SPS) at temperatures varying from 1200°C to 1400°C. XRD results indicated a relative stability of the BCC phase structure, with some phase segregations leading to the formation of some secondary phases in low percent. These secondary phases′ proportion and chemical composition varied depending on the alloy composition and sintering temperature. On the other hand, elevating the sintering temperature clearly enhances densification, although the extent of enhancement differs according to various alloy designs. Finally, the presence of the ductile‐element–enriched phases is expected to significantly influence the microstructure and contribute to the enhancement of mechanical properties, which will be explored in a subsequent study.