Study of pressure distribution and material removal in compliant polishing tools

Abstract

Polishing of complex geometric surfaces with high precision requires compliant polishing tools that can evenly and accurately remove materials. Compliant tools have a controllable surface that enables polishing of a large number of surfaces with varying complexity of contours. The aim of this study is to observe and record variations in contact pressure between polishing tool and work surface that occurs as a result of a change in the compliance of the polishing tool. This variation in pressure affects the material removal rate, depth of material removal and area of coverage. In this study, a compliant polishing tool design was selected and produced. The design consists of stiffeners that are housed inside ribs of a stiff rubber tool. The tool compliance is varied when the stiffeners are retracted resulting in a change of stiffness in the rubber tool, allowing for control of the material removal, pressure variation, and coverage area on the surface to be polished. Tool design was prepared on Solidworks, with the rubber tool base material selected based on the Shore A hardness, and the material properties being determined experimentally through compression tests on a dynamometer. The fabricated tool was initially used to carry out static tests to observe pressure distribution, followed by dynamic tests on varying work piece inclinations to observe material removal upon tool compliance variation. Trial tests were conducted on flat and curved surfaces to determine the effectivity of the tool based on material removal depth.