Review of additive manufacturing and post processing techniques for aluminium alloys with focus on microstructure changes mechanical performance and emerging trends

Additive Manufacturing (AM) has evolved into a revolutionary technology for producing complex three-dimensional (3D) near-net-shape components from computer-aided design (CAD) models. This study offers a thorough examination of progress in additive manufacturing processes and post-processing technologies for aluminium alloys, emphasizing critical techniques including Powder Bed Fusion (PBF), Cold Metal Transfer-Wire Arc Additive Manufacturing (CMT-WAAM), Selective Laser Sintering (SLS), and Selective Laser Melting (SLM). Although additive manufacturing provides substantial advantages such as design versatility, material efficiency, and expedited prototyping, it also poses numerous important problems that affect the performance and durability of aluminum components. These challenges encompass wear tracks, porosity, residual stresses, undesirable microstructural phases, suboptimal surface finish, diminished corrosion resistance, and constrained fatigue life, which limit their applicability in high-performance sectors such as aerospace, automotive, and biomedical engineering. Post-processing techniques are essential for improving the mechanical characteristics, surface integrity, and durability of additively manufactured aluminium components to address these difficulties. Heat treatment methods, including solutionizing, aging, and annealing, are crucial for enhancing microstructure and mechanical strength. Surface polishing methods, such as mechanical finishing, chemical etching, and laser treatments, enhance surface quality and diminish roughness, consequently improving corrosion resistance and wear performance. Moreover, hot isostatic pressing (HIP) has been widely employed to eradicate internal flaws, diminish porosity, and improve fatigue performance by exposing components to elevated temperatures and pressures. Integrating these post-processing procedures can dramatically reduce the constraints of AM-produced aluminum components, enhancing their suitability for rigorous industrial applications. This study emphasizes the necessity of enhancing additive manufacturing techniques and post-processing methods to produce high-quality aluminum components with improved functional characteristics.