Preparation of TiZrHfNbMo refractory high entropy alloy powder via hydrogen plasma-arc melting

Refractory high-entropy alloys (RHEAs) are a new type of metal materials composed of four or more refractory elements. However, the melting point and liquid viscosity coefficient of RHEAs are high, which leads to low fluidity. Therefore, powders of such alloys are difficult to prepare by conventional methods. In this study, a new method called a hydrogen plasma-arc melting has been developed for the preparation of RHEA powders. Results show that the TiZrHfNbMo RHEA powders have single body-centered-cubic (BCC) structures, consisting of a large number of irregularly-shaped powders and small numbers of spherical powders. The average particle size of the powder was 66.97 μm. There is no obvious composition segregation on the surface and inside of the RHEA powders. In addition, this method greatly reduces the oxygen content of the powders.