Applications of Titanium Alloys, Ni-Based Superalloys, and Aluminum Alloys in Powder Bed Fusion Additive Manufacturing: Process–Microstructure–Property Relationships, Defect Engineering, and Emerging Frontiers

Abstract

Powder bed fusion (PBF) additive manufacturing has emerged as a transformative near-net-shape fabrication technology for advanced metallic components across aerospace, biomedical, energy, and automotive sectors. This review establishes a processing-defect-microstructure-performance tetrahedron framework to systematically evaluate how laser powder bed fusion (LPBF) and electron beam powder bed fusion (EB-PBF) parameters govern the structural integrity and functional properties of six alloy families, with primary emphasis on titanium alloys, nickel-based superalloys, and aluminium alloys, while retaining ferrous alloys, copper alloys, and refractory metals as concise comparative cases. The thermal processing history is examined as the primary control dimension that deterministically shapes defect formation, microstructural evolution, and mechanical performance. Defect mechanisms spanning lack-of-fusion porosity, keyhole porosity, and cracking are analysed through a progressive hierarchy from energy-driven universal phenomena to material-specific manifestations. Microstructural control strategies, including solidification morphology engineering, phase transformation pathway manipulation, and grain boundary design, are synthesised across alloy systems. The mechanical performance hierarchy reveals that Ti-6Al-4V and nickel superalloys deliver the highest specific strength and creep resistance but exhibit greater sensitivity to defect-induced fatigue scatter, while 316L stainless steel and AlSi10Mg offer superior process robustness at moderate strength levels. Advanced characterisation techniques, in-situ monitoring capabilities, and multiscale simulation frameworks are surveyed as essential enablers for process qualification. Emerging frontiers in multi-material architectures, alloy design exploiting non-equilibrium solidification, and industrial scalability are critically assessed, identifying key knowledge gaps and future research directions toward qualification-ready PBF manufacturing.