High uniformity of the mechanical properties of arc-melted WNbMoTaZr refractory high entropy alloy

Elucidation of the variations of microstructure and mechanical properties of arc-melted refractory high entropy alloys (RHEAs) is important before their widespread practical applications. In this work, the uniformity of the mechanical properties of arc-melted WNbMoTaZr RHEA was investigated based on Weibull statistics under varying conditions. The results indicated that despite the significant variations in microstructure with threeparameter Weibull modulus (m3p) of about 1.5, the Vickers hardness demonstrated better uniformity with improved m3p of about 3.5. The compressive properties exhibited relatively-high uniformity under various test conditions, especially the yield strength (m3p = 8.7) and fracture strength (m3p = 8.5). The high uniformity of the mechanical properties was mainly attributed to the solid solution strengthening mechanisms. For different loading conditions, a superior uniformity of compressive properties of arc-melted RHEAs was obtained at a higher strain rate, while the compressive properties displayed an independence on the sample aspect ratio. Compared with conventional structural materials, the arc-melted WNbMoTaZr RHEA demonstrated better high uniformity and larger critical failure values.