Development of morphable polishing tools with labyrinth and dimple textures

Abstract

Inspired by the physical nature and functionality of morphable surfaces, this paper develops the polishing tools with such surface characteristics. The surface textures of morphable polishing tools can be tuned and adapted according to the stage and requirements of the targeted surface finish and material removal rate. To investigate the performance of morphable surfaces in polishing, morphable polishing tools with labyrinth, dimple and hybrid textures were fabricated by curing silicone materials with different Young’s moduli. The morphable polishing tools can be produced with fast responsiveness and reversibility by controlling the air pressure in the tool cavity. Fixed-spot polishing experiments with the developed morphable tools were performed on a copper surface, and the surface morphology, surface roughness and removed volume of polished copper were measured with a laser confocal microscope. Furthermore, static and dynamic polishing forces, polishing pressure distribution and interfacial friction coefficient between the tool and workpiece were obtained and benchmarked in polishing experiments regarding the labyrinth, dimple and hybrid tools. The results show that under the investigated polishing parameters, the roughness of polished surface is the smallest with the dimple tool, higher with the hybrid tool and the labyrinth tool. The material removal volume, static and dynamic polishing forces under different tool offsets are larger in the polishing processes with a dimple tool. In addition, the theoretical and experimental study indicates that the tool surface texture significantly affects the polishing pressure distribution. Labyrinth tools show denser pressure distribution owing to the finer textures of a smaller characteristic length, while dimple tools show sparsely distributed pressure owing to the coarser surface texture.