HEMA-TBA凝胶体系制备多孔氧化铝陶瓷

采用HEMA-TBA凝胶体系制备具有高气孔率, 高强度的多孔氧化铝陶瓷, 研究多孔氧化铝陶瓷的浆料和坯体制备工艺, 并系统研究了分散剂含量和固相体积分数对浆料粘度和悬浮稳定性的影响、干燥和单体含量对生坯性能的影响以及固相体积分数和烧结温度对烧结体微观结构的影响。结果表明: 加入柠檬酸可以使浆料粘度降低, 稳定性提高, 柠檬酸加入量达到2wt%后浆料粘度和稳定性趋于稳定; 固相体积分数的增加会导致浆料粘度和稳定性的增加; 生坯在干燥过程中的收缩比水基体系小很多, 干燥时间也相对更短; 单体含量对生坯强度影响较大, 当单体含量为25wt%时, 生坯强度较高; 通过选择不同的固相体积分数和烧结温度, 可以有效地控制烧结体的微观结构, 气孔率的变化范围在40%~65%, 同时烧结体强度也会随之发生变化, 变化范围在5.7~91.2 MPa。

Porous Alumina Ceramic Prepared by HEMA-TBA Gelcasting System

Porous alumina ceramics with high porosity and high strength were successfully fabricated by HEMA-TBA gelcasting system. Fabrication processes of slurries and ceramic were studied, effects of solid loading and dispersant contents on viscosity and stability of slurries, effects of drying and monomer content on green bodies, and effects of solid loading and sintering temperature on sintered bodies were investigated. The results show that optimum addition of citric acid of 2wt% decreases the viscosity and increases the stability of slurry. The viscosity and stability of the slurries increase with the increase of the solid loading of slurries. Green bodies with low solid loading can be dried with relatively small shrinkage less than 10% and its drying time is also relatively shorter than water based gelcasting system. The amount of monomer has great influence on green body and the strength of green body achieve high value at monomer content of 25%. By choosing the solid loading of slurries and sintering temperatures, ceramic microstructures and the porosity ranging from 40%-65% can be effectively controlled and strength of porous ceramics changes in the range of 5.7-91.2 MPa.