Comparative study of microstructure evaluation and mechanical properties of 4043 aluminum alloy fabricated by wire-based additive manufacturing

Abstract

4043 AlSi alloy samples are fabricated by laser-arc hybrid additive manufacturing and wire arc additive manufacturing. To investigate the influence of laser energy on the fabricated sample, the microstructure evaluation and mechanical properties are studied. After the input of laser energy, there are laser zones with finer grains and reduced Si segregation. As a result, the Si phases at grain boundaries in laser zone are smaller than that in other zones. And it is found that semi-coherent interface between Al and Si phases with crystal orientation relations, [110]Al∥[110]Si and (111)Al∥(220)Si, indicating the Si phase tends to grow along (111)Al plane. The results of mechanical properties show that the micro-hardness in laser zone is 54.3 HV0.05, with the increment of 19.08% compared to that in heat-affected zone. And the tensile strength, yield strength and elongation after the input of laser energy are 163.39 ± 1.68 MPa, 75.60 ± 4.91 MPa and 17.38 ± 5.44%, which are 7.56%, 8.45% and 3.45% higher than that without laser. The improved mechanical properties are due to the finer gains, reduced Si segregation and the crack deflection in LAHAM samples.