Hot deformation and hot processing behavior of deformable Tip reinforced Mg-5Zn-0.5Ca composite

Abstract

The spherical Ti particle (Ti_p) reinforced Mg-5Zn-0.5Ca (Ti_p/ZX50) composite was prepared via the semi-solid stirring casting process and the effects of Ti_p on the hot deformation and hot processing behavior of matrix alloy were investigated through uniaxial hot compression testing. The results indicate that a particle deformation zone (PDZ) forms around the Ti_p with the deformation of the Ti_p/ZX50 composite, which is propitious to the dynamic recrystallization (DRX) of the matrix alloy. The range of the PDZ and the promoting effect of the Ti_p on DRXed nucleation are inversely related to the deformation degree of the Ti_p. Moreover, the deformation of Ti_p alleviates the high stress in the matrix alloy during deformation, expanding the processing range and reducing the average deformation activation energy of the matrix alloy. Notably, the minimum processing temperature (493 K) of the Ti_p/ZX50 composite is significantly lower than that of hardened particle reinforced magnesium matrix composites. The hot deformation mechanism of the Ti_p/ZX50 composite is dislocation climb controlled by both lattice diffusion and pipe diffusion.