On the Enhanced Cryogenic Strength of a Dual-Phase TRIP-Assisted High Entropy Alloy

This study investigates the influence of deformation temperature on the microstructural evolution and mechanical performance of a dual-phase high-entropy alloy subjected to cold rolling after annealing at 750 °C for 30 min. Unlike the homogenized alloy, which exhibits a single-phase face-centered cubic structure, the processed condition develops a dual-phase microstructure with the inclusion of body-centered cubic phases. Uniaxial tensile experiments were conducted across a wide temperature range to evaluate the mechanical response. These results were correlated with microstructural observations to elucidate the underlying deformation mechanisms and guide property optimization. While the coarse-grained homogenized condition exhibited no phase transformation during deformation, the refined dual-phase structure demonstrated strain-induced phase transformation with its extent strongly dependent on the deformation temperature. Notably, the microstructure obtained after thermomechanical processing demonstrated enhanced transformation-induced plasticity effect at lower temperatures, achieving a tensile strength exceeding 1600 MPa and a failure elongation of approximately 18% under cryogenic conditions.