WU Xiaowen, ZHANG Zhijie, ZHAO Hang, HUANG Zhaohui, LIU Yan’gai, FANG Minghao, MIN Xin
(Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral
Materials, School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing 100083, China)
Abstract: Mica ceramic was prepared by pressureless sintering with phlogopite from the by-product of mineral processing as raw material and CaF2, Li2O, and ZrO2 as additives. The effects of the additives and the sintering temperature on the microstructure and mechanical properties of the prepared mica ceramics were studied. The results showed that CaF2 promoted the phase transformation of phlogopite to fluorphlogopite and diopside, and Li2O promoted its phase transformation to iron leucite and iron magnesium olivine. Meanwhile, ZrO2 contributed to the sintering densification of mica ceramics instead of phase transformation. The apparent porosity of the mica ceramic with ZrO2 as an additive was close to that of the mica ceramic without an additive and the bending strength increased with the increase of the sintering temperature. The bending strength of the mica ceramic with ZrO2 reached the maximum, 32.55 MPa, after sintering at 1000 °C. In general, the mechanical properties of the mica ceramic with ZrO2 as an additive were the best.
Key words: mica ceramic; ZrO2; Li2O; bending strength.