抄録
In order to develop the “Bio-filter”, silicon nitride porous bodies with micro-macro complex pore structure were fabricated using the tape casting process. Since the size of micro-pore must be larger than the one of microbes (about 1 micron) , methods for controlling the pore diameter were investigated. The effect of the mean particle size of the raw alpha-silicon nitride powder and sintering condition on the size of micro-pore of silicon nitride porous body was investigated using various commercial raw powders. The peaks of pore size distributions of all sintered bodies fabricated in this work were much smaller than 1 micron. It was difficult to enlarge the size of micro-pore by extending the sintering duration. To enhance the driving force for grain growth, a small amount of beta-silicon nitride ‘seed’ particles were added to the raw alpha-silicon nitride powders, and sintered at 1850°C for 4∼16h. After sintering for 16h, the peak of pore size distribution reached about 1 micron. Thus, it was confirmed that the ‘seed’ addition was effective to control the size of micro-pore.
