A Review on Microstructural Characteristics and Mechanical Performance of Additively Manufactured AlSi10Mg Alloy

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Metal additive manufacturing (MAM) is extensively being utilized by aerospace and automobile industries to produce parts with complex geometries with minimum lead time, no material wastage, and higher dimensional accuracy. Additively manufactured (AMed) AlSi10Mg alloys are one of the most used alloys in lightweight structural applications due to their tailored microstructure and suitable mechanical properties for these applications. This review critically presents the recent and current developments on the AlSi10Mg alloys fabricated using various MAM methods such as laser powder bed fusion (LPBF), directed energy deposition (DED), and electron beam melting (EBM). Special attention is given to the establishment of linkage among the process–structure–property–performance of the AMed AlSi10Mg alloy. This review highlights that LPBF-fabricated AlSi10Mg alloys typically exhibit a finer cellular α-Al matrix with a continuous Si network and provide superior strength with lower ductility. DED samples showed a coarser dendritic microstructure and exhibited moderate strength and ductility. However, EBM fabrication leads to near-equilibrium microstructures and exhibits reduced strength with improved ductility due to higher processing temperatures and thermal gradients. The effects of MAM methods, build orientations, and their process parameters on the microstructural evolution and mechanical performance of AlSi10Mg alloy products are extensively investigated. The influence of post-processing methods is also discussed, which reveals their critical role in the anisotropy, ability to mitigate defects like porosity and a lack of fusion, surface irregularities and material strengths. Despite showing steady progress in this area, several challenges like residual stresses, process-induced porosity, and limited availability of universal standardizations remain unaddressed. Such issues raise doubts about the reproducibility and adoption of the fabricated components on a large scale. This review study is likely to help the aerospace and automobile industries in the printing of structural components using an optimized parameter range, leading to an optimized microstructure and balanced mechanical properties with minimum defects. This review provides a comprehensive comparison of the LPBF, DED, and EBM processing routes for AlSi10Mg alloys by correlating the processing parameters to the microstructural evolution, mechanical properties, and fatigue performance. It indicates that the optimization of process parameters and post-processing treatments are the key strategies to reduce defects, control the microstructure, and obtain a good balance between strength and ductility. The review also points out the existing research gaps and future directions towards reliable industrial implementation of AMed AlSi10Mg components.