Ceramic body of zirconium dioxide (ZrO.sub.2) and method for its preparation

US4525464A · kind A · utility

Assignee

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US

Inventors

• Nils Claussen · Schwäbisch Hall, DE
• Manfred Ruhle · Ditzingen, DE
• Gunter Petzow · Echterdingen, DE

Key dates

• Filing date: Jun 12, 1984
• Grant date: Jun 25, 1985
• Expiry date: Jun 12, 2004

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B35/4885
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A ceramic body of zirconium dioxide containing, if desired, aluminum oxide, and partially stabilized with yttrium oxide and/or one or more rare earth oxides (e.g., cerium dioxide) and/or magnesium oxide and/or calcium oxide is partially stabilized with 0.5 to 5 mole-% of yttrium oxide and/or 5 to 12 mole-% of magnesium oxide and/or calcium oxide and/or cerium dioxide or one or more rare earth oxides, is 30 to 100% in the tetragonal lattice modification and has in the surface region a content of yttrium oxide, cerium dioxide, magnesium oxide, calcium oxide or rare earth oxide that is 1 to 20 mole-% higher than the average content, such that the body is coated with a thin, PSZ-like layer in a more highly stabilized tetragonal or with a layer that is predominantly in the cubic lattice form. For preparation, the surface of an already sintered or only presolidified compact of partially stabilized zirconium oxide is brought into intimate contact with yttrium oxide, cerium dioxide, magnesium oxide, calcium oxide and/or another rare earth powder or a zirconium dioxide powder containing at least 12 mole-% of yttrium oxide and/or other stabilizer oxides, and then annealed at 1000.degree. to …