Effects of plastic deformation on precipitation behavior and tensile fracture behavior of Mg-Gd-Y-Zr alloy

The effects of plastic deformation on precipitation behavior and tensile fracture behavior of Mg-10Gd-3Y-0.6Zr alloy were investigated. The results indicate that more precipitation cores can be provided by the crystal defects caused by the plastic deformation, as well as increasing the amount of β' phases, and the formation of precipitations at grain boundaries and interfaces between the twins and matrix. Because of an increase in precipitations, the dislocation slipping during deformation process is effectively hindered and the matrix is strengthened, especially for the 2% deformed alloy which can achieve a good combination of strength and ductility. With increasing the plastic deformation, the microcracks occur at the interface between grain boundary precipitations and matrix, and then propagate intergranularly. When intergranular fracture combines with the formation of smoothing facets on the fracture surface, the tensile properties decrease.