Investigation on microstructure and mechanical properties of Al-Si-Mg alloy fabricated by WAAM-UI hybrid additive manufacturing

In this study, ZL114A aluminum alloy wire was employed, and ultrasonic impact treatment was applied based on the WAAM process parameters to realize the WAAM-UI hybrid manufacturing of Al-Si-Mg alloy components. The application of ultrasonic impact treatment resulted in a reduction in the number and size of columnar crystals, with deformed grains becoming dominant in the alloy components and the number of recrystallized grains being significantly decreased. The second phases in WAAM-UI Al-Si-Mg alloy were found to be consistent with those in WAAM Al-Si-Mg alloy, mainly consisting of eutectic silicon and Mg2Si. The ultimate tensile strength (UTS), yield strength (YS), and elongation (El) of the WAAM-UI Al-Si-Mg alloy components are 205.6±7.1 MPa, 125.2±11.5 MPa, and 14.3±0.5%, respectively. Compared with the Al-Si-Mg alloy components prepared by WAAM, the ultimate tensile strength and yield strength of the WAAMUI Al-Si-Mg alloy components have increased by 13.9% and 38.6%, respectively.