Influence of Heat Treatment on Phase Stability and Strength–Ductility Balance in ZrTiWMoVTaNb Septenary Refractory High‐Entropy Alloy

Refractory high‐entropy alloys (RHEAs) are promising candidates for structural applications in environments requiring excellent mechanical properties at elevated temperatures. In this study, the WTiZrTaVMoNb RHEA was fabricated via mechanical alloying (MA) for 32 h, then consolidated by spark plasma sintering (SPS) and subsequently annealed at 1000°C for 6 h, and the influence process conditions on the phases, microstructure, and mechanical properties was explored. The as‐sintered alloy exhibited a dominant BCC matrix accompanied by minor secondary intermetallic phases. After annealing, partial dissolution of these secondary phases into the BCC matrix occurred, leading to improved elemental homogeneity and enhanced phase stability. The as‐sintered alloy exhibited the highest hardness (822 Hv) and plasticity (19.6%), whereas annealing reduced hardness by approximately 18%, improved plasticity by about 33%, and increased the ultimate compressive strength to 1722 MPa. Zirconium played a key role in enhancing ductility by refining grain boundaries and stabilizing the microstructure, whereas its synergistic interaction with titanium facilitated dislocation motion and improved the alloy′s plastic deformation capacity. These results demonstrate that controlling heat treatment conditions is an effective approach to tailoring the phase constitution and microstructure of RHEAs, achieving an optimal balance between strength, ductility, and thermal stability, and enhancing their potential for high‐temperature structural applications such as gas turbine blades, thermal protection systems, and nuclear reactor walls.