Effect of Fe2O3 addition on the sinterability and machinability of glass-ceramics in the system MgO–CaO–SiO2–P2O5

The sintering and the crystallisation behaviour of a glass in the CaO–SiO2–MgO–P2O5 system were studied by considering Fe2O3 as the nucleant agent. The addition of 5.0 wt.% Fe2O3 to the glass produces a sinterable glass-ceramic, with high relative density and mechanical strength. The glass-ceramic contains apatite, whitlockite and diopside phases at low temperatures and, in addition, wollastonite at high temperatures. The above-mentioned glass-ceramic has moderate machinability without onset of fracture.