Hydrothermal process for preparing zirconia-alumina base ultra-fine powders of high purity
US4769351A · kind A · utility
14Cited by
3References
8Claims
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Key dates
| Filing date | May 4, 1987 |
| Grant date | Sep 6, 1988 |
| Priority date | — |
| Expiry date | May 4, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/90
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for preparing a zirconia-alumina base composite ultra-fine powder is described, including the steps of: mixing an aluminum salt or an alumina hydrate with an aqueous zirconium oxychloride solution, with or without metal salt acting as a stabilizer; mixing urea or a substance capable of generating ammonia by hydrolysis with the resulting mixture; and allowing the mixture to react at a temperature of 140.degree. to 300.degree. C. and a pressure of 4 to 150 kg/cm.sup.2 in a high-temperature and -pressure vessel. The reaction product is further dried, calcined and crushed to obtain an ultra-fine powder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.