Research on the influence of abrasive particle size and lapping parameters on the surface scratches of stainless steel substrates

Abstract It is of crucial importance to minimize the surface scratches that occur during abrasive processes in order to maintain the mechanical properties of products, improve surface quality and reduce subsurface cracks. However, current research lacks an evaluation index system for assessing and controlling surface scratches on stainless steel substrates. Addressing this issue, an evaluation index for scratches based on the surface topography characteristics of the workpiece is proposed, which is utilized to assess the state of scratches on the workpiece surface. First, using image processing techniques to screen 3D scratch data on the workpiece surface addresses the challenge of extracting 3D scratch features. Second, a feature evaluation metric for assessing lapping scratches is designed based on the extracted combined features. Finally, the influences of the abrasive grain size and lapping parameters on the characterization of lapping scratch features are explored and analyzed. The results of the Analysis of Variance indicate that the effect of lapping time on the number of scratches does not achieve statistical significance. Regression analysis reveals that reducing abrasive particle size and lapping pressure significantly affect the number of scratches and the average scratch depth. Furthermore, a negative correlation is observed between the rotational speed of lapping pad and the number of scratches and the average scratch depth. Among these factors, abrasive particle size has the most prominent effect on the number of scratches and the average scratch depth. Specifically, when abrasive grains with a particle size of w10 are used for processing, the minimum number of scratches observed is 28, with an average scratch depth of 315.62 nm and the density distribution coefficient value is 0.31. Compared to the abrasive particle size w50, there is a decrease of 57.58%, 52.38% and 35.48%. The use of smaller-sized abrasive grains can significantly reduce the number of scratches and render them shallower and more concentrated in distribution. This method enables the analysis of the formation mechanism and patterns of scratches under various process parameters.