先驱体转化法制备氧化锆毡/氧化锆多孔复合材料的力学与热学性能研究  

Mechanical Properties and Thermal Conductivity of ZrO_2 Felt / ZrO_2 Porous Composites Fabricated by Precursor Conversion Method

作　　者：艾建平[1,2] 周国红[1] 王正娟[1,2] 张海龙[1] 王士维[1] 

机构地区：[1]中国科学院上海硅酸盐研究所结构陶瓷工程研究中心,上海200050 [2]中国科学院大学,北京100049

出　　处：《中国材料进展》2015年第12期916-920,915,共5页Materials China

摘　　要：采用氧氯化锆（ZrOCl2·8H2O）为氧化锆前驱体，利用真空一压力浸渍工艺将前驱体浸渍液引入氧化锆毡骨架中，循环浸渍、干燥、裂解12次；常压烧结（1450～1600℃）制备得到了低热导率和高力学性能的氧化锆毡／氧化锆多孔复合材料。研究了烧结温度对多孔复合材料的物相组成、体积密度、气孔率、压缩强度以及显微结构的影响规律，分析了多孔复合材料内部的热传导机制。研究结果表明：烧结温度1450℃时，有少量La2Zr2O7相生成；随着烧结温度提高，La2Zr2O7相消失，立方相氧化锆含量逐渐增多；同时，多孔复合材料的气孔率从50．5％降至45．5％，压缩强度从16．9MPa增至40．0MPa；在低温段多孔复合材料以声子传热为主，而在高温段材料内部气体对流传热起主导作用，获得的材料在100～1200℃温度区间热导率低于0．9W／（m·K）。ZrO2 felt/ZrO2 porous composites were fabricated by vacuum-pressure infiltration technique using ZrOCl2 · 8H2O as precursor. After 12 cycles of infiltration-drying-pyrolysis and sintering at 1 450 ~ 1 600 ℃, the porous composites with both low thermal conductivity and high mechanical strength were obtained. The effects of sintering temperature on compres- sive strength and thermal conductivity were investigated on the basis of composition, density, porosity and microstructure. The results showed that a little La2Zr2O7 phase was formed at 1 450℃ but disappeared when the sintering temperature in- creased. As the sintering temperature rose from 1 450℃ to 1 600℃, the content of c-ZrO2 gradually increased. Mean- while, the porosity decreased from 50. 5% to 45.5% and the compressive strength increased from 16.9 MPa to 40. 0 MPa. Possibly, phonon heat conduction dominated heat transfer of the porous composites in the low temperature range. While, convective heat transfer was dominated in the high temperature range. Thermal conductivity of the obtained composites was lower than 0. 9 W/（m · K） in the range of 100 ℃ to 1 200 ℃.

关 键 词：多孔陶瓷 ZRO2 先驱体转化法 压缩强度 热导率 

分 类 号：TB32[一般工业技术—材料科学与工程]