Effect of SiC particle distribution on the microstructure and texture evolution of SiCp/Mg–Zn–Ca–Zr composite during wedge-shaped rolling

The spatial distribution of ceramic reinforcements plays a critical role in controlling deformation heterogeneity, recrystallization, and texture evolution in particle-reinforced magnesium matrix composites. However, how different initial SiC particle distributions regulate the microstructural and textural evolution pathways during rolling remains insufficiently understood. In this study, SiC p /Mg-Zn-Ca-Zr composites with two typical particle distributions were compared: an as-cast state with necklace-like SiC particles along grain boundaries and an as-extruded state with a more uniform banded particle distribution. Both composites were subjected to wedge-shaped rolling at 250 °C to clarify the role of particle distribution in dynamic recrystallization and rolling texture evolution. In the as-cast composite, the clustered SiC particles induced strong local stress concentration and dislocation accumulation, promoting particle-stimulated nucleation and twinning-related recrystallization at low reductions. The heterogeneous deformation, together with twinning and multiple slip activation, contributed to a metastable rare-earth-like texture, which gradually transformed into a bimodal basal texture with increasing reduction. In contrast, the more uniformly distributed SiC particles in the as-extruded composite weakened local stress concentration and homogenized plastic deformation, facilitating continuous c-axis rotation toward the normal direction. Consequently, nearly complete recrystallization and a more uniformly refined microstructure were obtained at 50% reduction. These results reveal that tailoring the initial reinforcement distribution is an effective strategy for controlling recrystallization and texture evolution in magnesium matrix composites.