Investigation on high-deposition-rate directed energy deposition of Al-5%Mg alloy via external compound magnetic fields

Optimizing forming accuracy and improving deposition rate are the research hotspots in directed energy deposition (DED) of the aluminum alloy structures with medium-to-large size. This work employed a self-designed external compound magnetic fields (ECMFs) to enhance DED efficiency and forming accuracy simultaneously. Compared with the results of gas metal arc welding-based conventional-deposition-rate DED process with a low wire feeding rate, the deposition rate of the ECMFs assisted DED process was increased by 93.42%, surface roughness for each side of the cross-sectional samples was decreased by 52.86% and 82.73%, and the average grain size in the top and middle regions was decreased by 5.18% and 52.48%, respectively. The reasons for the high forming accuracy and acceptable mechanical property were explained distinctly. This novel method realized the high deposition rate of the DED process with good formability and performance.