| 摘要 |
PROBLEM TO BE SOLVED: To decrease the degreasing time and to prevent cracks by heating a zirconia ceramic formed body comprising a zirconia ceramic powder containing CeO2 and an org. binder in an atmosphere having specified or lower oxygen concn. to degrease. SOLUTION: A zirconia ceramic powder containing 8 to 12mol% stabilizer such as CeO2 by 100 pts.wt. is kneaded with 15 to 25 pts.wt. of an org. binder, and injection molded to form a zirconia ceramic formed body. Then inert gas such as nitrogen is mixed to the air to be introduced into a degreasing furnace to obtain an atmosphere having <20vol% oxygen concn. and the body is heat in this atmosphere. The heating process is carried out at 10 deg.C/hour temp. raising rate from the normal temp. to 250 deg.C, then at <=6 deg.C/hour from 250 to 400 deg.C, and further >=10 deg.C/hour from 400 to 500 or 700 deg.C to degrease the body. Then, the body is calcined to obtain a zirconia ceramic product. As for the org. binder, paraffin wax, stearic acid, acryl resin and styrene resin can be used. |
