Effect of laser power on microstructure and properties of 5356 aluminum alloy by laser induced MIG arc additive manufacturing

In order to improve the microstructure and mechanical properties of 5356-Al alloy produced by additive manufacturing with MIG welding, The article combine the low power pulse laser with MIG arc welding. In this paper, 5356-Al alloy wall-shaped parts were molded by pulse laser -MIG arc hybrid heat source with different laser powers, and the influence of laser power on the microstructure, microhardness and tensile properties of the deposited 5356 aluminum alloy were studied. The results show that wall-shaped parts produced by laser induced MIG arc additive manufacturing have a good metallurgical junction and fusion phenomenon. The microstructure of the wall is mainly equiaxed grains. Compared with MIG arc additive manufacturing, the equiaxed grains of the wall fabricated by laser induced MIG arc additive manufacturing become smaller and more homogeneous, which makes the micro hardness of the wall increased and the fluctuation smaller. The addition of laser can reduce the content of Fe element, Si element and hydrogen porosity, and improve the mechanical properties of the wall. When the laser power is 300 W, the tensile strength achieves the maximum value, which increases by 12% than the non-laser one.