Abstract: Compared with cold rolling, warm rolling can significantly reduce or completely eliminate microstructure damage to regulate the microstructure of the material, which is an effective method to improve the mechanical properties of the material. However, the effect of warm rolling on refractory complex concentrated alloys (RCCAs) has rarely been reported. This research examines how warm rolling influences the microstructure, texture, and mechanical properties of the Zr₄₅Ti₁₅Nb₃₀Ta₁₀ RCCA. The RCCA was warm-rolled to a 75 % reduction in thickness at 650 °C (two-phase zone) and then annealed at 1000 °C for 1 h. To highlight the advantages of warm rolling, a comparison was conducted with similarly deformed and annealed cold-rolled RCCA. The warm-rolled RCCA exhibits a layered heterogeneous structure and induces the precipitation of the (Nb, Ta)-enriched bcc2 phase. The deformation texture of warm-rolled RCCA is weaker than that of cold-rolled RCCA, which is attributed to localized deformation inhomogeneity. After annealing, warm rolling resulted in a remarkable increase in the yield strength of the RCCA, i.e., from 861 MPa to 1071 MPa; meanwhile, moreover, the tensile plasticity was almost identical. Warm rolling leads to a change in plastic deformation of the RCCA from dislocation cross-slip to one dominated by the interaction of dislocations with subgrain boundaries as well as the bcc2 phase. The back tress generated by the heterogeneous structure induced by warm rolling is also effective in increasing the yield strength of the RCCA. The remarkably layered heterogeneous structure, subgrain boundaries and textures result in warm-rolled RCCA with optimal strength-ductility combination. Our results provide an effective processing approach for tailoring the microstructure and mechanical properties of RCCAs.

Key words: Refractory complex concentrated alloy, Warm rolling, Heterogeneous structure, Mechanical properties