Microstructure and Mechanical Properties of TiZrHfCu0.5W0.5 Refractory High‐Entropy Alloy

In this article, tungsten (W) is introduced to prepare TiZrHfCu 0.5 W 0.5 refractory high entropy alloy (RHEA) for enhancing its mechanical properties and energetic attributes as energetic structural materials. Dynamic compression experiments are performed at strain rates ranging from 500 to 3000 s −1 across a temperature spectrum of 296–373 K. Then, a comparative analysis is conducted on the microstructural features of fracture surfaces and elemental distributions. The results reveal that the TiZrHfCu 0.5 W 0.5 RHEA exhibits a quasistatic compressive ultimate strength of 1470 MPa along with a compressive fracture strain of 17.25%, indicating robust load‐bearing capabilities. As the strain rate increases, the TiZrHfCu 0.5 W 0.5 RHEA ignites, accompanied by intense exothermic luminescence, and displays a notable positive strain rate strengthening effect, with a maximum dynamic compressive strength reaching 3.53 GPa. TiZrHfCu 0.5 W 0.5 RHEA exhibits typical brittle intergranular fracture characteristics, grain melting, and recrystallization that occurs on the fracture surface. High‐strain‐rate deformation induces a hybrid fracture mechanism combining quasicleavage and brittle fracture modes, which facilitates effective fragmentation and subsequently promotes combustion. The fitted Johnson–Cook model is proposed to describe the deformation behavior, and the predictions of the model are in good agreement with the experimental results.