Study on the Preparation of Refractory High-Entropy Alloys by Explosive Sintering

High-entropy alloys show noticeably better mechanical and physical properties than traditional alloys and have found widespread application prospects in the fields of national defense equipment, aerospace, high-pressure physics, and so forth. The preparation of high-entropy alloys largely involves the arc melting method, which displays defects like element segregation and low production efficiency in the preparation process. In this study, based on the mechanical alloying of a mixed refractory metal powder, the explosive sintering technology is adopted to prepare refractory high-entropy alloys (RHEAs). Through numerical calculations, the formation conditions of the solid dissolution phase of RHEAs and the minimum detonation pressure needed for explosive sintering are derived, and an explosive sintering test is performed with the explosive-powder tube ratio as a test variable. A dense bulk material containing the Mo-Nb-Re-Ta-W type of RHEAs is prepared through explosive sintering. The explosively sintered alloy products are characterized by x-ray diffraction analysis, scanning electron microscopy, energy dispersive spectroscopy, etc. The results show that the alloy products only contain the BCC phase and some Re elements that are not yet miscible, distributions of various elements are not completely homogeneous, and RHEAs are developed only in some parts of the product, implying the feasibility of the method for RHEA preparation.