Suppression of defect in plated film on AMed metal products by electron beam polishing

Additively manufactured (AMed) metal products with high shape accuracy can be produced by laser powder bed fusion (LPBF). However, the AMed metal products have large surface roughness due to the arrangement of bead shape. Surface irregularities such as spatter and small cavity are also generated on the surface. Furthermore, elemental composition of AMed metal products may be changed from that of original metal powder due to oxidation of surface. On the other hand, electroless plating has been applied to improvement of surface functions. However, defect is often generated in the plated film due to surface irregularities and oxidation of base material. Therefore, surface smoothing methods are required for suppression of defect in plated film.
In this study, surface smoothing and surface repairing of AMed aluminum (Al) alloy were performed by electron beam (EB) polishing with large-area EB. After the EB polishing, electroless plating was conducted on the AMed Al alloy, and suppression of defect in plated film was proposed. Experimental results show that surface smoothing, surface repairing and removal of oxidization layer of AMed Al alloy can be done simultaneously by the EB polishing. Furthermore, the plated film without defect can be successfully formed on the EB polished Al alloy.