The effect of B2O3, PbO and P2O5 on the sintering and machinability of fluormica glass-ceramics

Sintering, crystallization and machinability behavior of the SiO2-Al2O3-MgO-K2O-B2O3-F glasses were investigated. The optimum fluormica glass-ceramics with desirable sintering behavior and machinability were obtained by addition of PbO and P2O5 glass formers. Various parameters, e.g. the morphology of the mica crystal, relative intensity of the mica phase, the particle size distribution of chips obtained by drilling, microhardness, and the strength differences of glass-ceramics before and after drilling (Δσ) were investigated and compared with naked eye experiments.