Research Progress on Microstructure and Mechanical Properties of Magnetic Field Assisted Additive Manufacturing Metals

Metal additive manufacturing（MAM） technology has been widely used in various industries because it does not need molds and is not limited by structure. It has become an effective way to manufacture products with complex shapes.While it still faces challenges such as defect formed in as-built parts, material anisotropy, crack and elemental segregation.Magnetic field-assisted additive manufacturing（M-FAAM） characterized by diverse configurations, non-contact control and significant regulatory effects provides an innovative solution for controlling microstructures and mechanical properties in MAM. The influence mechanisms of magnetic fields on the MAM process were systematically elaborated, the formation mechanisms of deposition defects and their control strategies were analyzed, the impact of magnetic fields on the microstructure refinement and mechanical properties was reviewed. The current studies show that magnetic field assistance can influence molten pool flow and heat transfer, regulate solidification microstructure grain size, dendrite growth morphology and deposition defects, as well as improve material mechanical properties. However, the mechanisms governing molten pool motion behavior, the influence on solidification process and the correlation between microstructure and mechanical properties remain complex. In the future, further research is needed to uncover the precise regulatory mechanisms of magnetic fields on molten pool flow and microstructure, establ ish the relationship between magnetic field parameters/processes, microstructure and mechanical properties, and develop new magnetic fields suitable for additive manufacturing. These efforts will promote the practical application of M-FAAM in engineering and achieve high-quality metal additive manufacturing.