Microstructure of Mg-5Zn-3.5Sn-lMn-0.5Ca-0.5Cu alloy after hot compression

摘要

Microstructure of Mg-5Zn-3.5Sn-lMn-0.5Ca-0.5Cu alloy is studied after hot compression tests. The processing map is constructed using the strain rate sensitivity parameter from the power-law form of the constitutive equation. To identify the microstructure evolution for deformation conditions outside and inside the region suitable for hot processing. The microstructure after hot compression is studied. The results show that dynamic recrystallized grains with low fraction form along the grain boundary in the specimen deformed under conditions outside both unstable zone and the region suitable for hot processing. For deformation conditions inside the unstable zone, the plastic deformation is inhomogeneous with the appearance of curved lines containing fine dynamic recrystallized grains, cracks formed along the area with dynamic recrystallized grains which coordinate the inhomogeneous plastic deformation of the deformed grain and bear large plastic strain, the intense deformation lead to the nucleation of cracks. For deformation conditions inside the region suitable for hot processing, partially dynamic recrystallized microstructure forms. This is consistent with the processing map.