Investigation of Cr content, second phase, and sintering temperature on characteristics of WMoVTiCr refractory high entropy alloys

Refractory high-entropy alloys (RHEAs) are important candidate materials for the design of advanced high -temperature structural materials. In this work, WMoVTiCr RHEAs were synthesized by mechanical alloying. The effect of Cr variation, second phase formation, and sintering temperature on microstructural evolution and mechanical properties of the model alloys were investigated. The results demonstrate that the alloy mainly consists of BCC solid solution phase, Ti-rich oxides, and a trace of Cr-rich phases. The hardness and compressive strength increase significantly with increasing Cr content, which could be ascribed to the dispersion strength-ening of second-phase particles and the effect of Cr on the solid solution strengthening. However, the presence of a high amount of Cr content can lead to the reduction of compressive strain due to an increase in the brittle Cr-rich phases. Moreover, a lower sintering temperature caused an incomplete solid solution, thereby reducing material performance.