Hot deformation and dynamic recrystallization behavior of cocrni and (Cocrni)₉₄ ti₃ al₃ medium entropy alloys

The CoCrNi and precipitate-hardened (CoCrNi)₉₄ Ti₃ Al₃ medium entropy alloys (MEAs) have attracted much attention, due to their exceptional mechanical properties, whereas the hot deformation characteristics have not been revealed. In the present study, we investigated the dynamic recrystallization behavior and microstructure evolutions of the two MEAs hot-compressed at single-phase temperatures. The constitutive equation was obtained, and microstructures were observed. Discontinuous dynamic recrystallization acted as a key mechanism of grain refinement at a relatively higher temperature and lower strain rate, which leads to the formation of a homogeneous grain structure. The addition of Ti and Al promoted dynamic recrystallization due to the solid solution hardening effect. The results provide valuable guidelines for microstructure refinement via thermomechanical processing.