Interface characterization of Mg-7Al-1Ca alloy reinforced by integrated 3D[sbnd]Cu open-cell foam

Abstract

In this study, a 3DCu open-cell metal foam has produced through investment casting, then molten Mg-7Al-1Ca has penetrated through the 3DCu open-cell foam to produce the composite. The composites were heat treated at 290 °C and 480 °C for 1 h to find the adhesion mechanism at the interface of Mg-7Al-1Ca/3D-Cu open-cell foam. Then, the microstructural and mechanical properties of the Mg-7Al-1Ca/3D-Cu open-cell foam interface were investigated by metallography, micro-hardness, and punch-out test. The results indicate that the shear strength of the Mg-7Al-1Ca/3D-Cu interface is a function of the diffusion bond thickness and types of intermetallic phases. The as-cast sample tolerated 98.5 MPa shear stress. However, the 480 °C heat-treated sample has the most fracture toughness compared to the 290 °C heat-treated and the as-cast samples, 84.7, 75.6, and 35.1 J/mm3, respectively. Therefore, the heat-treatment cycle, T = 480 °C, t = 1 h, with decreasing 9.5% (98.5 to 89 MPa) of the shear strength led to an 140% (35.1 to 84.7 J/mm3) increase in energy absorption density of the interface of the composite.