Weld morphology, microstructure evolution, and mechanical properties of laser beam welding of wire arc additive manufactured Al-Cu substrate

Abstract

Laser welding is a feasible process for joining the additive manufactured (AMed) parts to meet the manufacturing demand of specific large-scale components. Microstructure and property evolution as well as weldability of the laser welding of wire arc additive manufactured (WAAMed) Al-Cu alloy are investigated. Results indicate that the WAAMed Al-Cu alloy has excellent laser weldability and the joint is nearly free of defect. The width of the heat-affected-zone (HAZ) and equiaxed crystal zone (EQZ) as well as the grain size of the fusion zone (FZ) will increase with higher laser power and heat input. The joint with laser power of 3500 W has the highest tensile strength and elongation, reaching 203.48 MPa and 4.13%. The result from electron backscatter diffraction (EBSD) test indicates that the texture intensity will affect tensile properties. The tensile strength and elongation of the laser welded WAAM sample perpendicular to the deposition direction are higher than that parallel to the deposition direction. The microhardness value of HAZ is higher than that of FZ and BM due to 163 HV. The feasibility of laser welding of WAAMed samples is validated, and process parameters are found for hybrid manufacturing of large-scale components.