Direct Metal Additive Manufacturing Processes and Their Sustainable Applications for Green Technology: A Review

The sustainability of manufacturing processes is one of important issues in the aspect of green technology to deal with global warming and finite resources. Direct metal additive manufacturing (DMAM) processes are widely used to fabricate three-dimensional metallic parts with geometrical complexity through layer-by-layer deposition of metallic materials. The layer-by-layer deposition characteristics of the DMAM process can easily create a freeform geometry with characteristic shapes and a heterogeneous structure with different materials unlike the conventional manufacturing (CM) process. The inherent characteristics and the promising merits of the DMAM can provide a solution to improve the sustainability of the manufacturing process. This paper reviewed the DMAM processes and their sustainable applications for green technology. Principles and characteristics of the DMAM processes were investigated. The state-of-the art and important issues related to sustainable applications of DMAMprocesses were discussed. Finally, significant opportunities and future research issues of the DMAM process were discussed from the viewpoint of the improvement of sustainability.