Laser Powder Bed Fusion of Metallic Materials: Process Fundamentals, Critical Parameters, Defect Mechanisms, and Future

Abstract

The advent of Metal Additive Manufacturing has greatly changed the face of modern manufacturing, enabling the fabrication of intricate metallic components from threedimensional computer-aided design (CAD) models. Among the available metal additive manufacturing techniques, Laser Powder Bed Fusion (LPBF) is considered one of the most advanced and widely used methods due to its ability to produce near-net-shaped products with high dimensional accuracy and good mechanical properties. The technique has gained popularity in industries ranging from aerospace and biomedical to automotive, energy, and tooling, where lightweight and customizable designs are required. Although there are many advantages, the quality of LPBF-manufactured components is heavily influenced by process parameters, thermal histories, powder characteristics, and melt pool dynamics. An inappropriate choice of parameters frequently leads to flaws such as porosity, lack of fusion, residual stresses, cracking, and poor surface finish, which affect the structural integrity of the parts produced. This paper reviews the basic concepts of LPBF, the impact of key process parameters on part quality, and the common mechanisms underlying defect formation, microstructure evolution, and mechanical performance. Moreover, advancements in process monitoring, quality control, and intelligent manufacturing are mentioned. Finally, existing problems and future perspectives are examined to advance reliable and sustainable LPBF manufacturing