A review of additive manufacturing of metallic materials assisted by electromagnetic field technology

Although additive manufacturing (AM) technology has been developed for many years, traditional metallurgical defects are inevitable most of the time by solely optimizing process parameters. To improve the manufacturing quality of as-built AMed parts, the electromagnetic (EM) field may show great potential for online use through the magnetohydrodynamics effect on the melt pool. This work aims to give a dedicated review of the application of EM fields state-of-art in metal AM processes. The working principle and metal solidification theory in the EM field are elucidated, followed by a review of typical EM fields that have been used and how they are arranged in AM processes. The effect of EM fields on melt temperature characteristics and the transient melt flow during the manufacturing process, the subsequent influence on macro and microstructure characteristics, and finally the mechanical properties of the AMed parts are discussed. This work is expected to be helpful for a critical understanding of the EM-field-assisted AM process of metallic materials and the mechanisms of EM effect in AM processes up to date.