Preparation and Properties of Porous α-Al2O3 Based Ceramic Disk Substrates

Porous α-Al2O3 based ceramics disks were prepared by dry pressure molding method. Influences of sin- tering temperature and SiO2 dopant on the structure, morphology and properties were investigated. It was founded that compressive strength and shrinkage ratio of α-Al2O3 ceramic disk both increased with increasing sintering temperature. The shrinkage ratio and compressive strength was less than 0.5% and stronger than 80 MPa, respec- tively, while the optimum sintering temperature was chosen to be 1180℃. The sintering of α-Al2O3 ceramic disk would be enhanced by doping SiO2, which crystallized into cristobalite phase from an amorphous phase during the sintering process. α-Al2O3 ceramic disk doped with 12wt% SiO2 sintered at 1180℃ exhibited a stronger compres- sive strength (110 MPa) and a shrinkage ratio of 1.2%. The ceramic disk possessed a smaller pore size but a wider pore size distribution than that of the pure α-Al2O3 ceramic disk. It was demonstrated that both α-Al2O3 and SiO2 doped α-Al2O3 ceramic disk substrates were favorable for the growth of ZSM-5 zeolite membranes. However, these ZSM-5 zeolite membranes showed different morphologies and crystal sizes, due to the difference in physicochemi-