Simulation of surface roughness and topography in finish turning using digital image subtraction

Most surface roughness prediction models based on mathematical approach assume a geometrically well-defined nose profile, i.e. either circular or elliptical. Such simple models cannot be applied in cases where the tool nose develops different wear patterns or have non-geometric arbitrary profile, such as those caused by manufacturing tolerances in the nose radii. In this study, a digital simulation method using binary image subtraction is used to generate the work piece surface topography, and from which the common roughness parameters of the work piece are determined. Comparison of the digital simulation method with the theoretical models using ideal nose shape shows a maximum difference of 4.7% in the average roughness value.