Tian Li, Wang Lijuan, Wang Kailei, Zhang Yuedan, Liang Jinsheng
Key Laboratory of Special Functional Materials for Ecological Environment and Information (Hebei University of Technology), Ministry of Education, Tianjin, 300130, People's Republic of China.
Institute of Power Source and Ecomaterials Science, Hebei University of Technology, Tianjin, 300130, People's Republic of China.
Sci Rep. 2019 May 14;9(1):7337. doi: 10.1038/s41598-019-43918-9.
In this paper, a new type of porous ceramics was prepared using the raw sepiolite mineral. The porous ceramics was shaped by the dry pressing method and sintered in the range of 700 ~ 1200 °C. The temperature-microstructure evolution and the properties of porous sepiolite ceramics were investigated by thermo gravimetric and differential thermal analyses (TG-DTA), X-ray diffraction (XRD), bending strength, compressive strength, scanning electron microscopy (SEM) and mercury intrusion porosimeter (MIP). The sintering kinetics of the porous ceramics from sepiolite was investigated by means of stepwise isothermal dilatometry (SID). The mechanical properties improved with the increasing sintering temperature, and the bending strength and compression strength reached a maximum of 52 MPa and 32 MPa respectively at 1200 °C. The porosity increased with the sintering temperature until 1100 °C attaining the value of 55.40% and then decreased to a value of 46.48% at 1200 °C. The main crystal phases of the porous ceramics were akermanite and diopside. At 1200 °C, the pores inside the ceramics basically follows a unimodal distribution, which was mainly located near 553 nm. The sintering activation energy of porous sepiolite ceramics was measured by step isothermal thermal expansion with a value of 791.42 kJ/mol in the range of 1000 °C to 1200 °C.
本文采用天然海泡石矿物制备了一种新型多孔陶瓷。该多孔陶瓷采用干压成型法，并在700~1200℃范围内烧结。通过热重与差热分析（TG-DTA）、X射线衍射（XRD）、抗弯强度、抗压强度、扫描电子显微镜（SEM）和压汞仪（MIP）研究了多孔海泡石陶瓷的温度-微观结构演变及性能。采用逐步等温膨胀法（SID）研究了海泡石多孔陶瓷的烧结动力学。力学性能随烧结温度的升高而提高，在1200℃时抗弯强度和抗压强度分别达到最大值52MPa和32MPa。孔隙率随烧结温度升高至1100℃时达到55.40%，然后在1200℃时降至46.48%。多孔陶瓷的主要晶相为钙镁黄长石和透辉石。在1200℃时，陶瓷内部孔隙基本呈单峰分布，主要位于553nm附近。采用逐步等温热膨胀法测得多孔海泡石陶瓷在1000℃至1200℃范围内的烧结活化能为791.42kJ/mol。
