Sintering behavior and mechanical properties of the mica–diopside machinable glass-ceramics

The machinability of fluor-mica glass-ceramics is an attractive characteristic of these materials. However, the poor mechanical strength and hardness has limited their applications.In this research, to overcome this problem, a glass frit in the system CaO–SiO2–P2O5–MgO was gradually added to a mica-based frit. After sintering of compacted mixtures, simultaneous crystallization of diopside and mica occurred that led to improved mechanical properties. The sinterability of various samples was investigated and their microstructure and crystallinity were evaluated by electron microscopy (SEM) and X-ray diffraction (XRD). The presence of plate-like crystals of mica, spherical particles of apatite and fibrous inclusions of diopside was the microstructural specification of the optimum composition.The four-point bending strength and the Vickers microhardness of samples were also determined.