Microstructure and mechanical properties of wire + arc additively manufactured Al-Mg-Si aluminum alloy

Al-3.1Mg-2.0Si ternary aluminum alloy thin wall component was built with double - wire + arc additive manufacturing process by synchronously feeding ER5087 (Al-5Mg) and ER4043 (Al-5Si) wires. The microstructure and mechanical properties were tested and studied. The results showed the main existed phase were α-Al, Mg2Si and Al9Si. Al-Mg-Si eutectics (α-Al + Mg2Si + Al9Si) distributed along the grain boundary in α-Al matrix. The micro hardness was about 54.7HV. The ultimate tensile strength, yield strength and elongation of the deposit in horizontal direction were 176 MPa, 76.6 MPa and 11.4%, respectively. The properties in vertical direction were slightly lower. An isotropic feature of the tensile properties was exhibited in the deposit.