Zirconium oxide powder, process for its preparation and its use

US5252316A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Gangolf Kriechbaum · Alzenau, DE
• Peter Kleinschmit · Hanau, DE
• Doris Peuckert · Hofheim, DE

Key dates

• Filing date: Aug 20, 1990
• Grant date: Oct 12, 1993
• Expiry date: Aug 20, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/80
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Crystalline zirconium oxide powder with a BET surface of less than 30 m.sup.2 /g, preferably 10 to 20 m.sup.2 /g, a primary particle size of 0.1 to 0.5 .mu.m, a monoclinic crystal structure and, optionally, a content of Y.sub.2 O.sub.3 of 1 to 10% by weight and/or of 1 to 10% by wt. MgO. It is produced by adding an aqueous zirconium salt solution optionally containing yttrium ions and/or magnesium ions under agitation into a vessel which contains an aqueous base solution such as e.g. sodium hydroxide solution with a content of NaOH which corresponds to an excess of at least 0.5 mole/l NaOH. The mixture obtained in this manner is then treated hydrothermally at a temperature of 200.degree. to 400.degree. C., the product obtained is separated by filtration, washed chloride-free with water and dried at 100.degree. to 120.degree. C. The zirconium oxide powder can be used to produce sintered ceramics.