Manufacturing of three-layered sandwich composite of AA1050/LZ91/AA1050 using cold roll bonding process

Abstract

In this paper, for the first time, dual-phase Mg-Li alloy is used to produce a three-layered Al/Mg/Al composite with the use of the cold roll bonding process. The low density and high ductility are known as the essential advantages of the Mg-Li alloys, while a couple of important problems should be taken into account, namely low corrosion resistance and low strength. It has been tried to deal with the mentioned problems by performing cold work and cover the Mg sheet with the Al similar plates. To investigate the Mg-Al layers bonding quality, mechanical properties and microstructure were examined for different thicknesses reduction ratio. The peeling test results showed that with increasing rolling pressure, the size and number of cracks on the brittle surfaces due to brushing, surface expansion, and metal extrusion between the cracks were improved by rising the reduction thickness ratio, bond strength enhanced, sharply. The UTS of 33.33% thickness reduction three-layered Al/Mg sample was obtained 186.5 MPa, which was more than 2.1 and 1.3 times higher than the initial Al1050 and MgLZ91 samples, respectively. However, because of increasing the amount of thickness reduction, roll-bonded layers’ quality, the tensile strength of the composite, and the microhardness of both layers increased. Furthermore, the elongation has reduced, and the maximum ultimate tensile strength and microhardness were achieved at 66.67% thickness reduction.