Deformation-induced homogenization of the multi-phase senary high-entropy alloy MoNbTaTiVZr processed by high-pressure torsion

Dendritic microstructures are frequently observed in as-solidified refractory high-entropy alloys (RHEAs), and their homogenization typically requires a long-term heat treatment at extremely high temperatures. High-pressure torsion (HPT) has been shown to be capable of mixing immiscible systems room temperature, therefore represents promising technique for homogenizing dendritic RHEAs. In this work, the RHEA MoNbTaTiVZr was processed up 40 revolutions by HPT. It found that microstructure eliminated, resulting chemical homogeneity von Mises equivalent shear strain about 400. The study deformation mechanism showed an initial localization, followed co-deformation interdendritic regions. step, Zr-rich region gradually disappeared. deformation-induced also led formation ultra-fine grained (UFG) microstructure, exhibiting grain size approximately 50 nm. microhardness increased from 500 HV 675 homogenized UFG state. underlying mechanisms responsible enhancement, such as refinement solid solution strengthening, were discussed.