Characterization of surface texture in electropolishing processes using 3D surface topography parameters

Abstract

Surface engineering requires new technology for the evaluation of surface texture. Profiling methods for the characterization of surface finish do not permit the detailed analysis of surface microgeometry. Thus, advances in the field of surface metrology have led to the development of topographic profilometer systems capable of the three-dimensional topographical reconstruction of real surface texture using phase shift scanning of surfaces, with instruments able to measure microgeometric form, waviness, and roughness, individually or integrated. The innovative three-dimensional evaluation methods, using contact and non-contact technology, enable the virtual reconstruction of surfaces for the evaluation of area roughness parameters, three-dimensional topographic maps with color scale, and profiling of sections in any area of a surface to provide the two-dimensional roughness parameters, among others. In this study a set of 3D surface parameters were analyzed: fractal analysis, area roughness parameters (Sa, Sz, and Spd), and three-dimensional surface topography, in order to determine the information provided by each in the analysis of surface texture. The topographic analysis performed detected deformations on the borders of the workpieces when high electropolishing times and current densities were combined, due to the lack of homogeneity in the elimination of the treated surface material. Finally, this study has determined electropolishing conditions and electrolytic effects on surface texture using the three-dimensional analysis of surface texture.