Effect of Bending Angle on Defect Formation in ER4043 Aluminum Alloy in Wire Arc Additive Manufacturing

Direct energy deposition using an arc source (DED-Arc), also known as wire arc additive manufacturing, is a promising technique to fabricate large engineering components due to the high deposition rates. ER4043 aluminum alloy is widely used as a commercial feedstock for DED-Arc. However, defects such as porosity and cracking pose significant challenges and affect process reliability, particularly in real parts with more complex geometries. This study investigates the influence of the deposited geometry (bending angle in zig-zag tracks) on microstructure and defect formation in ER4043 fabricated by DED-Arc. Experimental results show that increasing bending deviations in bent corners intensify defect formation because of the thermal profile variations and localized stress accumulation during solidification. Additionally, distinct grain morphologies and defect distributions are observed at the interior and anterior edges of bent corners. These findings highlight that zig-zag tracks can be used as a practical approach for improving process reliability and defect control for industrial-scale DED-Arc in aluminum components.