Longitudinal Milling and Fine Abrasive Finishing Operations to Improve Surface Integrity of Metal AM Components

Growing market of additive manufacturing and in particular, metal AM has allowed the manufacturers to produce a wide variety of complex designs with near-net shape in minimum time without the need for custom tooling. However, the application of additive manufactured components in various applications, e.g., biomechanical contacts, naval and aerospace components are limited due to its poor surface integrity and part feature tolerance limits. Traditional methods, e.g., milling, do provide solution to some of the post-processing needs, however, results in poor material utilization, requires custom tooling or may be completely infeasible for complex geometries. In the current work, we focus on developing a post-processing strategy by coupling traditional machining processes with non-traditional fine abrasive finishing (FAF) methods. Preliminary results on 316 L stainless steel components fabricated via laser powder-bed fusion suggests that the proposed post-processing strategy can be used to (a) selectively impart surface finish S_a < 25 nm, and (b) reduce the surface porosity by ∼89% when compared to the as-fabricated sample.