Influence of Rare‐Earth Elements on the Mechanical Properties and Shock‐Induced Energy Release Characteristics of Al _0.5 NbZrTi _1.5 Ta _0.8 High‐Entropy Alloy

Refractory high‐entropy alloys (RHEAs) have garnered significant attention as potential reactive structural materials due to their excellent mechanical properties. Nevertheless, the high energy release threshold and limited energy release characteristics associated with them have significantly restricted their development and application. In this study, it was observed that the incorporation of RE elements (Ce, Dy, and Er) into RHEAs led to a reduction in the initiation temperature of exothermic reactions and an enhancement in the intensity of shock‐induced energy release processes. Notably, when Ce was incorporated into the RHEAs, the initiation temperature of exothermic reactions exhibited a pronounced decrease, dropping from 783°C to 391°C, and the specific calorific value (calorific value per unit mass) demonstrated an increase exceeding 100%. Upon the incorporation of rare‐earth (RE) elements into RHEAs, the resulting alloys are still characterized by high yield strengths exceeding 1 GPa and appreciable plasticity greater than 15% under quasi‐static loading. Microstructural characterization elucidated the effects of RE elements on grain refinement, interfacial segregation, and dislocation behavior. The considerable mechanical properties and energy release characterization render the RHEA containing RE elements a compelling candidate for reactive structural applications in anti‐armor technologies, with significant implications for the development of advanced reactive structural materials.