Influence of the Hot-Pressing Rate on the Interface Feature and Mechanical Properties of Mg/Al Composite Plates

Abstract

In this work, Mg/Al composite plates were prepared by direct hot pressing under atmospheric conditions. The impacts of the strain rate (from 3.3 × 10−4 s−1 to 1.0 × 10−2 s−1) on the interface and bonding strength were investigated. Results showed that Mg/Al composite plates can be successfully fabricated by hot pressing with a 40% strain at 350 °C. The strain rate will largely affect the interfacial bonding quality and the structure of the interface. As the strain rate decreases, the thickness of the diffusion layer at the interface becomes thicker, and the composition of the interface gradually changes from a mixed zone of Mg17Al12 and Mg2Al3 to two single-phase zones. In all samples, the Mg2Al3 phase layer at the interface tends to exhibit brittle fracture during shear. When the strain rate of the hot pressing reduces to 3.3 × 10−4 s−1, the single-phase zone of Mg2Al3 at the interface breaks up. In the present work, the Mg/Al plate hot pressed at a strain rate of 1.0 × 10−3 s−1 demonstrates the highest shear strength.