Development of fiber flow finishing (FFF) process for polishing hip prostheses

Abstract

In this paper, a new polishing process has been developed based on a smart polishing media called fiber flow finishing (FFF). The proposed polishing media included styrene butadiene rubber (SBR), coarse sisal fibers, and naphthenic oil. During the process, the rheological behavior of the polishing media changes intelligently due to severe mechanical disintegration and chemical treatment. This intelligent behavior is very similar to the behavior of pseudo-plastic materials. To evaluate the polishing performance, experiments were performed on the femoral head of hip prostheses grade ASTM F138 (SS 316L) for the different number of finishing cycles to investigate its effect on the percentage change in surface roughness (%ΔR a ). The experimental results clearly showed that the %ΔR a of the femoral head is low in the initial finishing cycles (i.e., up to 200 working cycles), while the %ΔR a increases to 72.54% with an increase in the number of finishing cycles up to 1000. Moreover, the surface morphology of the specimens well substantiated that the FFF process performed a kind of surface modification on the surface texture of the femoral head, resulting in a smooth and uniform surface finish without surface defects that is as a mirror. • The fiber flow finishing (FFF) process is first developed for polishing hip prostheses. • The surface finish of the femoral head was improved by 72.54% using the FFF process. • The FFF process performed a kind of surface modification on the femoral head surface. • The FFF process has a better performance than the abrasive flow finishing (AFF) process. • The FFF process has a promising future to improve surface integrity of industrial parts.