Evolution of roughness parameters along polishing tests of previously ground surfaces

Abstract

In polishing tests, precise determination of polishing time needed is difficult, since representation of surface roughness against polishing time leads to an asymptotic curve. In the present work, results of the polishing tests of previously ground surfaces are presented. Different roughness parameters were considered. Grinding wheels of 100 and 150 Norton grain size respectively were used. Cutting speed was 25 m s-1 and depth of cut was 0.02 mm. Two different feeds were considered: 9 m min-1 and 15 m min-1. A polishing test was performed by means of corundum polishing pads of grain size 2500. Results show that, the higher the initial grain size of the grinding wheel, the higher initial roughness is as expected. Amplitude roughness parameters such as Ra and Rq decrease with polishing time. Regarding material percentage parameters, Rk and Rpk decrease more sharply than amplitude roughness parameters in the first 20 s of the polishing test, and afterwards decrease slightly. Rvk decreases more slowly than amplitude roughness parameters along the polishing test. Keywords: grinding, polishing, roughness parameters