Evaluation of mechanical properties and fracture toughness of aluminum-magnesium-aluminum composite produced by cold roll bonding process

In the last few years, researchers have been interested in the fabrication of laminated composite sheets. In this research, mechanical properties and fracture toughness of three-layer aluminum-magnesium-aluminum composite sheet produced by cold-rolling bonding method were investigated. Mechanical properties and fracture cross-sections of the specimens were studied by uniaxial tensile test, hardness test and scanning electron microscopy, respectively. It was observed that the tensile strength of composite specimens was higher than that of aluminum and the microhardness and fracture toughness values were increased compared to the initial specimens. High applied cold work can be the main reason for the increase in hardness and fracture toughness, and the reason for the decrease in composite strength over magnesium is the creation of plastic instability in the magnesium reinforcer due to the high strain.The results of scanning electron microscopy also show that the fracture mechanism is for the soft aluminum layer and for the crisp magnesium and the surface of the fracture cross section in the aluminum layer has a shallower and smaller micropores, indicating shear ductile fracture.