Study on tensile fracture behavior of Mg-11.21Gd-1.74Y-0.38Zr alloy

AMg-11.21Gd-1.74Y-0.38Zr (wt%) alloy was prepared in a crucible electromagnetic induction furnace with a gas protection device. The mechanical properties at different temperatures were obtained via tensile testing. The fracture morphology was analysed by scanning electron microscopy. The morphology of the longitudinal section near the fracture surface was observed by optical microscopy. The dislocation density after tensile testing was analysed by x-ray diffraction. The results indicate that the tensile stress and dislocation density increased and then decreased as the tensile testing temperature increased. The maximum values of the tensile stress and dislocation density were obtained at 250 degrees C. In addition, the strain increased with increasing tensile testing temperature. The fracture morphology changed from brittle fracture to ductile fracture, and the fracture mode changed from transgranular fracture to intergranular fracture with increasing tensile temperature. A schematic diagram of crack initiation and propagation at different tensile temperatures was constructed.