Finishing of Additively Manufactured Metal Parts by Abrasive Flow Machining

Surface finishing is still a crucial challenge in metal Additive Manufacturing (AM) as the as-built surface roughness is difficult to fulfill service requirements, due to staircase effect, balling effect inherent to AM. Abrasive flow machining (AFM) is a non-conventional finishing technique that offers better accuracy and efficiency for parts with difficult-to-access structures, and the application of AFM to finishing metal parts of AM process is discussed in this paper. The aluminum and titanium grilles by selective laser melting are taken to explore the finishing effect of outer and inner surfaces. The AFM process parameters of abrasive grits sizes, abrasive media viscosity, and tooling designs are optimized to implement effective material removal from the outer and inner surfaces. The results show that the AM grille parts with non-trial internal structures can be finished efficiently and consistently by AFM.