Effect of deposition strategies on microstructures, defects and mechanical properties of 5356 aluminum alloy by wire arc additive manufacturing

Wire arc additive manufacturing (WAAM) is performed to study the effects of three deposition strategies on the 5356 aluminum alloy (AA5356) components. Three deposition strategies are reciprocating scanning (RS), oscillating scanning (OS) and vertical scanning (VS), respectively. The microstructures, defects and mechanical properties of AA5356 components are fundamentally explored. The results show that the VS strategy makes the uniform heat distribution of components. The microstructures with the VS strategy are mainly composed of equiaxed grains, compared with those with RS and OS strategies. The equiaxed grains lead to the highest microhardness (HV 77.25). The porosity and micropore size of the component with the VS strategy are reduced by 45.52% and 19.81%, respectively, resulting in improved tensile properties. Thus, the VS strategy provides a new solution for obtaining AA5356 components with uniform microstructure and excellent mechanical properties.