Enhancing the Surface Precision for the Helical Passageways in Abrasive Flow Machining

Abrasive flow machining (AFM) is an efficient means of deburring, surface polishing, and removing recasting layers from machined components. However, a smoother surface is not easily created after polishing since one-way motion of abrasive media in the traditional AFM. Therefore, this study designs a novel helical passageway to perform multiple flowing paths of an abrasive medium in order to reduce the surface roughness. There are several helical cores with different machining parameters have been performed to finish the circular holes; surface roughness uniformity and roughness improvement rates (RIR) are evaluated after AFM. The results indicate that a helical passageway performs better in reducing RIR by approximately 76%compared with a RIR of nearly 60%from the original circular passageway. In addition, the optimal design of helical cores includes a four-helix groove, a 0.5mm gap, a 0.5mm thickness of the helical slot and one helical turn. Based on experimental results, it is found that abrasive media in the helical passageways creates notable efficiency for good surface roughness and uniformity in the AFM process.