Surface finish improvement of medium-sized mold steel using an innovative sphere-like polishing tool with force control

The aim of this study is to develop an innovative sphere-like polishing tool, which applied on a machining center, to improve the surface finish of medium sized STAVAX plastic mould stainless steel. A polishing wheel as the polishing tool was driven in two rotational axes to generate movement like spherical polishing. The STAVAX specimen was burnished using ball burnishing process as a pre-surface finish improvement. Then, the polishing process using the innovative sphere-like polishing tool was conducted as the further improvement. The polishing processes with force control and without force control were investigated. A sliding control methodology was applied to the force control of the polishing process. Based on the comparison of both of polishing processes, it was shown that the polishing process with force control had better surface finish uniformity. It was proved not only by the visual inspection but also by the statistical analysis because the polishing process with force control had smaller variance value than without force control.