Review on field assisted metal additive manufacturing

Additive manufacturing (AM) offers unprecedented design freedom and manufacturing flexibility for processing complex components. Despite the numerous advantages of AM over conventional manufacturing methods, there are still some issues and bottlenecks that hinder the wide-scale industrial adaptation of AM techniques. The emerging field-assisted additive manufacturing (FAAM) is a designation that combines different auxiliary energy fields (e.g., ultrasound, magnetism, etc.) to overcome limitations in AM by benefiting from the intrinsic advantages of auxiliary fields. This work provides an up-to-date and dedicated review of FAAM in metallic materials, assisted by mainstream auxiliary magnetic, acoustic, mechanical, and thermal fields, as well as some emerging fields. The work principle and interaction mechanism between the field and the deposited metallic materials are elucidated. FAAM processes simulation and modelling are also reviewed. The auxiliary fields can affect the melt pool convection and dynamics, alter the temperature profile and thermal history during material solidification and induce stress or plastic deformation to the deposited materials. Hence, the effects of the auxiliary fields on the melt pool dynamics, solidification kinetics, densification behaviour, microstructure and texture, mechanical properties and fatigue performance are reviewed and discussed in detail. The perspectives on the research gap and further development trends of FAAM are also discussed.