Textural evolution and recrystallization mechanisms in isotropic hot-extruded Mg–Y-Nd-Gd-Zr alloys following annealing

Magnesium alloys are widely used in aerospace, automotive, and electronic communications sectors due to low density, high specific strength and excellent damping properties. Severe basal texture induced by thermal deformation severely limits subsequent plastic forming, which can be effectively regulated by annealing. In this work, the ECAP-processed Mg–Y-Nd-Gd-Zr alloy was subjected to isochronous annealing at 200–400 °C for 1 h and isothermal annealing at 250 °C for 0–90 min. Combining quasi-in-situ EBSD, TEM characterization and mechanical property tests, the static recrystallization behavior, texture evolution and intrinsic mechanism were systematically investigated.The static recrystallization initiates at 200 °C, and annealing at 250 °C for 1 h is identified as the optimal parameter to achieve favorable recrystallization degree and strength-ductility balance. Annealing recrystallization is divided into nucleation (0–30 min) and grain growth (30–90 min). Texture evolution is dominated by the nucleation stage, with TCC and TCD grains becoming the major texture components. Y-rich particles promote recrystallization through the PSN effect, while Nd/Gd co-segregation at grain boundaries exerts solute drag to inhibit grain growth differentially. TCD grains gain preferential growth advantage owing to weak solute drag, low stored energy and low-energy grain boundaries. This study clarifies the coupling mechanism of recrystallization and texture evolution, providing a theoretical basis for the engineering application of rare-earth magnesium alloys.