Surface finish improvement of additive manufactured metal parts

Unlike materials subtractive technologies, Additive Manufacturing (AM) works on producing near net shape components according to a specific design at which the synthesis is achieved layer by layer. Additive manufacturing allows design freedom, making design-driven manufacturing a reality. However, its poor surface quality is considered as one of the key challenges that are worth to overcome. The main objective of this chapter is to report a comprehensive overview of the techniques used to improve the surface finish and their advancements of products made by metal Additive Manufacturing (AM) technologies and to highlight experimental processes and data. Powder bed fusion (PBF) and direct laser deposition (DLD) are the main processes covered in this review. The chapter starts with the literature review and introduction to the main metal AM processes and their surface roughness limitations, the effect of their parameters and the effect of the laser re-melting on the surface quality. Which then followed by details on the post-processing surface finish techniques such as laser polishing, chemical, and electro polishing. Experimental results of post surface finishing of AM parts by micro electrical discharge machining are also presented.