| 摘要 |
PROBLEM TO BE SOLVED: To increase the rate of sedimentation of a slurry for casting contg. powdery ceramic stock, a binder, a dispersant and curdlan and to improve productivity at the time of casting by dissolving the curdlan by a specified method. SOLUTION: An alkali agent such as ammonia is added to a slurry contg. powdery ceramic stock such as Si3 N4 , AlN, Y2 O3 or Al2 O3 , a binder such as saccharides, a dispersant such as ammonium polycarbonate and curdlan (β-1,3- glucan) to adjust the slurry to >=pH9, preferably 9-12, especially preferably 9.5-11 and the curdlan is dissolved. Casting is carried out in a short time, density distribution in a cast body is made uniform and cracking at the time of drying and firing is suppressed. |
