Microstructure and Mechanical Properties of Mica Glass-Ceramics Prepared by Pressureless Sintering a Phlogopite and Various Additives

Mica glass-ceramics were prepared by pressureless sintering with a phlogopite and various additives as raw materials. The effects of CaF2 content, Li2O content, ZrO2 content, and sintering temperature on the microstructure and mechanical properties of the mica glass-ceramics were investigated by X-ray diffraction, scanning electron microscopy, and mechanical testing, respectively. The results show that the additive of ZrO2 has the best reinforcing effect on the flexural strength of the mica glass-ceramics. The smaller powder particles and the larger forming pressure result in the larger bulk density of the mica glass-ceramics samples. The main crystallite phases of samples with ZrO2 as additive were phlogopite and quartz with sintering temperature lower than 1120 ℃. The crystal phase of glass ceramics appeared fiberform and cross arranges with good lap. The highest value of flexural strength, 63.7 MPa, was shown on sample with 10wt% ZrO2 as additive and sintering temperature of 1120 ℃.