莰烯基冷冻浇注成型法制备Al_2O_3多孔陶瓷

Preparation of Porous Al_2O_3 Ceramic by Camphene-based Freeze-casting

采用莰烯基冷冻浇注成型工艺制备了氧化铝定向贯通直孔结构的多孔陶瓷。借助DNJ-1型旋转式粘度计、扫描电子显微镜、显气孔率容重测试仪等表征方法,研究了固含量对料浆粘度的影响、坯体升华干燥行为随时间变化的影响、固含量与孔隙率的关系以及氧化铝多孔陶瓷孔的方向和断面显微结构。结果表明：在固含量为10~50vol%范围内的料浆,经冷冻干燥,在1650℃下烧成,制备出了平均孔径在10~50μm、气孔率在14%~78%、固含量为10vol%时,抗压强度高达15.6 MPa的氧化铝定向贯通直孔结构的多孔陶瓷,并且固含量与孔隙率呈线性关系。

The oriented and aligned porous alumina ceramics was prepared by a camphene-based freeze-casting technique.The effect of solid loading on viscosity of slurry,the effect of time on green body sublimation behavior,the relationship between solid loading and porosity,pore direction and fracture microstructure of porous alumina ceramics were investigated by means of the NDJ-1type rotating viscometer,scanning electronic microscope,apparent porosity and bulk density tester.The results show that high-porosity alumina ceramics with oriented and aligned pores were prepared by freezing alumina/camphene slurries and porosity is in 14%-78% with solid loading ranging from 10vol% to 50vol%,followed by freeze-drying in air and fired at 1650 ℃.The samples had the moderate pore size in 10-50 μm and the compressive strength is more than 160.7 MPa.Finally,the linear equation of solid loading and porosity is obtained.