| 摘要 |
PROBLEM TO BE SOLVED: To produce a silicon nitride porous ceramic suitable for the abradable shroud of a ceramic gas turbine. SOLUTION: This method for producing a silicon nitride porous ceramic comprises the first process for coating the surface of α-silicon nitride powder having an average particle diameter of 5-12 μm with the sol of an oxide sintering auxiliary in an amount of about 0.25-7% converted into the oxide component, the second process for adding a molding auxiliary to the coated powder, kneading the mixture and subsequently molding the kneaded product, the third process for defatting the molded product, and the fourth process for sintering the defatted product at a temperature of 1,650-1900 deg.C in a 1-9 atm nitrogen atmosphere for 1-6 hr. Thus, the silicon nitride porous ceramic having a porosity of 30-50% is produced. |
