Feasibility and Reliability of Laser Powder Bed Fused AlSi10Mg/Wrought AA6061 Hybrid Aluminium Alloy Component

Laser powder bed fusion (LPBF) provides an effective and economical solution for fabricating multi-material components of complex structures as it entails a layer-wise manufacturing process. The feasibility and reliability of depositing AlSi10Mg alloy on the wrought AA6061 alloy substrate using the LPBF process were studied. The study includes the analysis of metallurgical quality, microstructure evolution, mechanical properties, and corrosion behaviour of the multi-material parts before and after heat treatment. The interface region, decorated with epitaxial growth, shows excellent metallurgical bonding without apparent defects of pores and cracks. LPBF AlSi10Mg comprises fine equiaxed grains and coarse columnar grains on the boundary and inside the molten pool, respectively. They were replaced by large Si particles after heat treatment without altering the grain morphology and <100>//BD (building direction) texture. The as-built multi-material part exhibits a low ultimate tensile strength of 192.8 ± 3.4 MPa, similar to that of wrought AA6061, and a higher elongation (13.6 ± 0.5%) than the LPBF AlSi10Mg alloy (9.4 ± 0.2%). In addition, the ultimate tensile strength and elongation of the multi-material part were slightly improved after heat treatment. Compression testing showed that, in contrast to single-alloy parts, the multi-material part achieved moderate strength and good compressive capacity under both as-built and heat-treated conditions. Interestingly, the galvanic corrosion effects in the interface region are suppressed for both as-built and heat-treated multi-material parts. Moreover, the as-built multi-material sample has a higher corrosion resistance than the heat-treated one. This study verifies the feasibility of efficiently manufacturing a reliable, excellent, and low-cost multi-material component combining conventional and additive manufacturing processes.