Effect of tensile loading–unloading cyclic plastic deformation on 4043 aluminum alloy manufactured through CCDR

In this study, a novel continuous casting direct rolling (CCDR) fabrication process was used to manufacture the 4043 Al alloy wire rods, and the feasibility of 4043 Al alloy as high-strength aluminum-alloy fasteners was investigated. Because the 4043 Al alloy have excellent castability, weldability, high specific strength, and wear resistance, they are used widely in industrial products. In this study, CCDR 4043 Al alloy wire rods was processed into specimens suitable for testing, and they were subjected to repeated tensile loading–unloading tests (pull and release) with stress exceeding the yield strength to investigate the transformation of their microstructure and the mechanical properties of this material after repeated plastic deformation. In our experiment, the tensile strength and elastic modulus of the 4043 Al alloy increased significantly within 500 cycles of plastic deformation, but after 750 cycles, although the strength continued to increase, internal microvoids reduced the elastic modulus. In addition, during the tensile loading–unloading process, the precipitation of the eutectic Si led to a nonuniform stress distribution that caused irregularities in the tensile fracture surface. This study analyzed the cyclic tensile loading–unloading effect on the CCDR 4043 Al alloy, and the findings aid the application of CCDR Al alloy fasteners.