Refinement of the microstructure during superplastic deformation of extruded Mg94Ni3Y1.5CeMM1.5 alloy

The microstructure and mechanical properties of extruded Mg94Ni3Y1.5CeMM1.5 alloy were evaluated between 250 and 400 °C. The alloy exhibited superplasticity between 300 and 400 °C. Superplastic deformation was characterized by the refinement of coarse second-phase particles and their continuous redistribution in the magnesium matrix. The equiaxed structure of the magnesium matrix in the deformed samples as well as the stress exponent close to 2 indicated that grain boundary sliding was the mechanism controlling the superplastic deformation.