Tailoring the non-coherent interfacial precipitation to overcome the trade-off between strength-ductility and impact energy release in Ti–Zr–Hf–Nb–Ta high entropy alloy

Abstract

The energetic high-entropy alloys have brought a new idea for the development of new energetic structural materials (ESMs) with high energy density and excellent mechanical properties. However, the energetic high-entropy alloys exhibit a significant trade-off between strength-ductility and impact energy release efficiency. Here, we develop a new strategy to introduce non-coherent interfacial nanoprecipitates into the Ti–Zr-Hf-Nb-Ta BCC energetic high-entropy alloy, which can not only exert the precipitation strengthening mechanism to maintain excellent mechanical properties, but also transform the local shear fracture into multiple cracks along the grain boundary to promote energy release. The nanoprecipitation-strengthened energetic high-entropy alloy achieved a four-times greater fireball area generated by impact energy release than that of the single-phase BCC alloy, while maintaining an excellent mechanical property combination of high dynamic compression strength (1787 MPa) and high fracture strain (40 %). The results provide new insights into the development of energetic high-entropy alloys with superior impact energy release and strength-ductility synergy.