A review on severe plastic deformation based post-processes for metal additive manufactured complex features

Additive manufacturing (AM) technologies revolutionized the manufacturing sector by enabling the production of complex components. But, the poor surface integrity hinders the direct functional application of as-built components and drastically affects the mechanical and tribological performance. In the last decade, researchers employed various post-processing techniques to improve the surface integrity of AM components. Thermal and chemical energy-based post-processes result in thermally destroyed and chemically modified surface layers on the finished surface. In contrast, mechanical energy-based post-processing techniques do not result in any modified finished surface integrities, due to which these techniques were extensively used for post-processing the AM components. The current article focuses on mechanical energy-based severe plastic deformation post-processing techniques to improve the surface integrity of the metal AM components. A detailed review of the published literature specific to each of these processes was carried out, and the research gaps are presented and adequately discussed in this paper.