Consideration on zinc content on the microstructure, mechanical, and corrosion evolution of aluminum/zinc composites fabricated by CARB process

Abstract

Aluminum/zinc laminated composites with different zinc contents (20 and 50 wt%) were fabricated in the form of sheets by using cross-accumulative roll bonding (CARB) process. Microstructural investigations by scanning electron microscopy showed the properly uniform distribution of thin zinc layers in the aluminum matrix in both laminated composites. The mechanical properties of the specimens were investigated by tensile, wear, and micro-hardness tests. Tensile results revealed that by increasing the zinc content, tensile strength is improved from about 275 MPa for 20 wt% zinc to about 350 MPa for 50 wt% zinc after the 8th cycle of CARB. Wear tests in the different zinc contents showed that the variation of the wear rate versus the number of rolling cycles has a similar behavior in both zinc contents. However, wear resistance was improved by increasing the zinc content in the laminated composites. Electrochemical corrosion tests were also carried out on both composites at different cycles. The results reflected that the composite samples containing 20 wt% zinc have better corrosion properties in comparison to that with 50 wt% zinc content at different cycles. In conclusion, this study pointed out the potential of aluminum/zinc laminated composites fabricated by CARB for further development.