Simulation and experimental investigations into abrasive flow nanofinishing of surgical stainless steel tubes

Surface roughness is one of the critical properties that affect the performance of biomedical devices and human implant's functions. Higher surface roughness leads to the comparatively higher probability of body fluid retention in the surface valleys. Surface roughness peaks can easily obstruct the flow of body fluid and drug. Abrasive flow finishing (AFF) is an advanced finishing process, which can produce nano-level surface finish in complex components. In this paper, experimental investigations, including parametric study on nanofinishing of surgical stainless steel 316L tubes using AFF process has been reported. Indigenous multiple polymers blended base medium was developed to perform the nanofinishing experiments. Based on the experimental results, statistical model has been presented. To understand the AFF process in depth, finite element approach has been implemented to determine the finishing forces generated during the AFF experiments. Initial surface roughness on the internal surface of the workpiece varies in the range of (0.67-0.50) mu m. The best surface finish of 48nm with a percent improvement (% R-a) of 92.20% has been achieved after processing the workpiece with AFF process. Simulated results are validated with the experimental results and the deviations are in the acceptable range.