A micro-model of the material removal depth for the polishing process

In this paper, a prediction model of the material removal depth for the polishing process is developed from the microscopic point of view. Based on the statistics analysis, and by the use of the elastic contact theory and the plastic contact theory, the relationship between the pressure and the depth of indentation is obtained. Moreover, the calculation equation for the linear removal intensity, which is the material removal depth per unit contact length along the polishing path, is presented. Finally, by integrating the linear removal intensity, the micro-model of the material removal depth for the polishing process is developed. Analyzed from the perspective of the abrasive grains, the model takes the grit designation and the structural number as the two basic variables for abrasive grains characteristics, and it is assumed that the shape of an abrasive grain is conic with spherical tip and the distribution of its protrusion heights is taken to be Gaussian distribution, which fully takes into account the impact of the abrasive grains characteristics on the depth of removal. In the model, different stages of the polishing process are decomposed in detail, and the reality that the plastic deformation is accompanied by the presence of elastic deformation is taken into consideration, which makes the model more realistic. Experimental results are compared with the prediction results to verify the theoretical model. The model can be used as the theoretical foundation for the selection of abrasive grains and the process parameters.