Microstructure and Mechanical Behavior of Mg-Based Bimetal Plates with High Formability Sleeve by Co-extrusion

In this study, microstructure and mechanical behavior of two types of Mg-based bimetal plates with a high formability sleeve were systematically studied, with a great emphasis on the effect of the interface characteristic and the sleeve fraction on the plasticity of composite plates. The rule of mixtures (ROM) for elongation was also addressed. The results show that when there is no or thin diffusion layer with thickness of about 3 μm, Mg-based bimetal plates have a good plasticity with elongation of about 19–24%, and the ROM predicted elongations are very close to the experimental ones. In contrast, with a diffusion layer about 95–155 μm thick, Mg-based bimetal plates exhibit a poor plasticity with elongation of about 11–17%, and the experimental elongations largely deviate from the ROM predictions. The plasticity of Mg-based bimetal plates increases with increasing sleeve fraction. This study provides new insights on the plastic deformation of Mg-based bimetal composites with a high formability sleeve.