Wear life characterization of the grinding wheel for electrolytic in-process dressing (ELID) grinding of ball bearing raceways: a new perspective based on a moving normal distribution curve of the grit state variation

Abstract

Many advantages make electrolytic in-process dressing (ELID) grinding desirable for cutting hard and brittle material with high surface requirements. The self-electrolytic in-process dressing property in ELID grinding is also largely responsible for the shorter wear life and lower forming accuracy of the grinding wheel. In ELID grinding, except for traditional mechanical wear, the electrolytic oxidation wear also adds more uncertainties to the wear velocity of the grinding wheel. To date, few investigations focused on the grinding wheel wear life characterization in ELID cut-in grinding of ball bearing raceway. In this study, the wear life characterization of the grinding wheel during ELID grinding was quantitatively simulated by a moving normal distribution curve of the grit state variation. As all types of cutting grits wear out, so did the normal distribution curve, showing movement towards the grinding wheel center. With the normal distribution curve moving towards the grinding wheel center, a local acceleration and local deceleration in moving velocities occurred. It is the diversity of the moving speed of the normal distribution curve that provides a quantitative description to understand the wear life characterization of the ELID grinding wheel. Some experimental results can easily explain this new proposed perspective. This new perspective can also be extended to predict the forming accuracy and surface topography of the bearing raceway during ELID grinding.