PURPOSE: To remarkably improve the strength of a ceramics sintered body by impregnating a ceramics formed-body or ceramics presintered-body with an aq. soln. of zirconium salt, and immersing this impregnated ceramics body in an alkaline soln. to deposit zirconium hydroxide on the above ceramics body, and drying, then sintering the zirconium hydroxide-deposited ceramics body.
CONSTITUTION: The formed- or presintered-ceramics body of ≤3μm mean particle diameter is impregnated with the aq. soln. of zirconium salt, and this impregnated ceramics body is immersed in the alkaline soln. to deposit the zirconium hydroxide on the above ceramics body. The obtained zirconium hydroxide- deposited ceramics body is dried, and then sintered. The ceramics concerned with this invention are exemplified in an alumina, mullite, sialon, silicon nitride, silicon carbide, etc. An aq. soln. of ammonia is favorable as the alkaline soln. The favorable impregnation treatment with the aq. soln. of zirconium salt is to use the aq. soln. of zirconium salt containing 15W30wt.% as a Zr at 60W90°C.
ISHIGURO TOMOAKI
TAKABAYASHI SOTOHIRO
