Ductile-Mode Material Removal of a Mica–Glass-Ceramic

The influence of crystal volume fraction on machining behavior was investigated for modified mica–glass-ceramic materials that contained B₂O₃, Na₂O, Li₂O, and ZnO and had low melting temperatures. The machining behavior was characterized by drilling rate under a constant drilling force and chip morphology in a cutting test. To achieve the greatest drilling rate, an optimization volume fraction of crystalline mica (40%) had to be used; a further increase in the fraction of crystalline mica resulted in a corresponding decrease in the drilling rate. For this type of mica–glass-ceramic, a continuous band of chips and a highly smooth cut surface could be formed during the cutting test at a high cutting velocity of 60 m/min and a depth of 1 mm. The results demonstrated that an outstanding machining behavior for glass-ceramics can be achieved and that it can be comparable with metallic materials.