Influence of Heat Treatment on Surface Finishing and Hard Anodic Coating Quality of Laser Powder Bed Fusion Processed AlSi10Mg

This study explores the crucial role of optimized heat treatment and post-processing techniques in improving the surface quality and performance of Laser Powder Bed Fusion (LPBF)-processed AlSi10Mg alloy for engineering applications. The rapid solidification during LPBF produces an ultrafine α-Al cellular network surrounded by Si-rich eutectic phases, which directly influence the substrate microstructure and dictate the effectiveness of subsequent surface treatments. Following heat treatment significantly impacts the compatibility of the substrate for chemical-based post-processing methods, i.e., electropolishing and anodizing. Microstructural transformations, including the fragmentation of the Si-rich network, enable smoother, glossier finishes during electropolishing and influence oxide coating properties. Variations in coating thickness, compactness, and defect formation during anodizing directly affect corrosion resistance and dielectric performance. These findings demonstrate that the substrate microstructure and quality, shaped by heat treatment, are key determinants of surface post-processing outcomes, underscoring the importance of tailored heat treatment and post-processing methods for achieving optimal surface properties and performance in LPBF-processed Al alloys.