Fabrication, microstructure and mechanical properties of the as-rolled ZW31/PMMCs laminate

Abstract

In present work, the ductile Mg–Zn–Y alloy (ZW31) was introduced into the 10 μm 15 vol% SiCp/AZ91 composites (PMMCs) to coordinate the deformation of PMMCs during the rolling process, then the ZW31/PMMCs laminate with the thickness of ~1 mm was prepared successfully. The microstructure and mechanical properties of the as-rolled ZW31/PMMCs laminate before and after the annealing process was investigated, the results indicated that existence of ZW31 alloy layer can absorb energy and relieve stress concentration of PMMCs layer by the formation of twins, which not only break through the bottlenecks of poor toughness of PMMCs, but also make it possible for the rolling of PMMCs sheet. The recrystallization behavior of the ZW31 alloy layer and PMMCs layer was completely different during the subsequent annealing process. For the ZW31 alloy layer, recrystallization induced by twinning, while the recrystallization in PMMCs layer related to the introduced particle. The typical rolling texture was formed in the ZW31/PMMCs laminate, and the intensity of which was mainly controlled by the ZW31 alloy. Application of annealing process improved the elongation of the ZW31/PMMCs laminate, however, at the expense of strength. Cracks originate in different positions of PMMCS layer and then connect with each other along the direction which perpendicular to the stress. The existence of ZW31 alloy layer inhibits the propagation of crack and is propitious to improve the ductility of ZW31/PMMCs laminate.