Numerical simulations of grinding force and surface morphology during precision grinding of leucite glass ceramics

Leucite glass ceramics are high-performance denture materials due to their high mechanical strength, excellent light transmittance, and excellent biocompatibility. Glass-ceramic denture must be processed using precision grinding technology to achieve a satisfactory surface integrity. To understand the contact interaction between the abrasives and workpiece, a theoretical model of grinding force during grinding of leucite glass ceramics was developed by considering elastic-to-ductile transition depth, brittle-to-ductile transition depth, strain rate effect, and random distributions of the abrasive position and size. In addition, a surface morphology model was developed to understand the material removal and deformation behaviors during grinding of leucite glass ceramics, which considered the brittle-to-ductile transition depth, elastic recovery, and random distributions of the abrasive position and size. The mechanical properties of leucite glass ceramics used in the models were measured by nanoindentation and nanoscratch tests. Grinding experiments of leucite glass ceramics were performed to verify the accuracy of the models, and the results showed that the predicted errors of the force and surface morphology models were within 10% and 15%, respectively. Both theoretical and experimental results demonstrated that small abrasive size, low feed speed, small grinding depth, and high grinding speed were beneficial to improving the surface quality, and large abrasive size, low feed speed, small grinding depth, and high grinding speed were beneficial to decreasing the grinding force. The results will provide a theoretical guidance for optimizing process parameters during high-efficiency and precision grinding of hard and brittle solids.