High-temperature dynamic mechanical properties of V_0.5Nb_0.5ZrTi refractory high entropy alloy fabricated by multi-wire arc additive manufacturing

Refractory high entropy alloys (RHEAs) are a promising class of alloys with superior high-temperature mechanical properties Multi-wire arc additive manufacturing (MWAAM) offers a cost-effective and highly efficient route for fabricating RHEAs. However, research on the high-temperature and dynamic mechanical behavior of MWAAM-produced RHEAs remains unreported. In this study, a V_0.5Nb_0.5ZrTi RHEA was successfully fabricated using MWAAM. The microstructure, as well as the static and dynamic mechanical properties of the alloy at various temperatures, were systematically investigated. The results show that the deposited V_0.5Nb_0.5ZrTi RHEA is free of cracks and defects, and it exhibits a multiphase microstructure, which is beneficial for overcoming the strain softening commonly observed in BCC-structured high-entropy alloys during dynamic loading. The alloy exhibits excellent strength and plasticity under dynamic compression, with the strength improved by 2.5 %–36.6 % compared to the commonly used Ni-based superalloys and a RHEA with similar composition. Moreover, both the yield strength and plastic strain of the V_0.5Nb_0.5ZrTi RHEA increase with rising strain rate, showing a synergistic improvement in strength and ductility. This study provides valuable data and insights for the development and manufacturing of high-performance, low-cost, ductile V_0.5Nb_0.5ZrTi RHEA.