Predictive model for minimum chip thickness and size effect in single diamond grain grinding of zirconia ceramics under different lubricating conditions

To address the current bottleneck of debris formation mechanism in plastic removal for hard-brittle materials, a minimum chip thickness (h(min)) model that considers lubrication conditions (represented by frictional angle beta) is developed according to strain gradient, as well as geometry and kinematics analyses. Model results show that h(min) decreases with increasing beta. Furthermore, grinding experiments using single diamond grain under different lubricating conditions are carried out to verify the model. With increasing beta, h(min), values are 71.6, 57.8, 52.0, 50.7, 45.6, 39.7, and 32.4 nm, thereby verifying the trend of h(min) decreasing with increasing beta. Furthermore, the location of size effect occurs is determined according to the variation trend of single abrasive particle specific energy and unit grinding force curves. The size effect occurs in the border area of ploughing, the cutting region, and mainly, in the ploughing region. Theoretical analysis results are consistent with experimental results with a model error of 6.06%, thereby confirming the validity of the theoretical model.