Microstructure and Mechanical Properties of a Combination Interface between Direct Energy Deposition and Selective Laser Melted Al-Mg-Sc-Zr Alloy

Selective laser melting (SLM) and direct energy deposition (DED) are two widely used technologies in additive manufacturing (AM). However, there few studies on the combination of technologies, which can synthetically combine advantages for more flexible material design. This paper systematically Al-Mg-Sc-Zr alloy by SLM DED with emphasis its bonding properties, microstructure, metallurgical defects. It is found that aluminum prepared methods achieves a good combination. The microstructure composed equiaxed crystals, large number Al3(Sc, Zr) precipitated phase particles rich Sc Zr. crystals columnar fine-grained area at boundary molten pool. With decrease volumetric density (VED), width depth pool interface junction gradually decrease. porosity increases VED, microhardness shows downward trend. Tensile strength elongation fracture printed sample 133.3 J/mm3 about 400 MPa 9.4%, while depositioned 280 5.9%. Due to excellent performance, this research has certain guiding significance SLM–DED composite alloy.