Preparation of calcined ceramic powders
US5863468A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1997 |
| Grant date | Jan 26, 1999 |
| Priority date | — |
| Expiry date | Oct 31, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/776
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Calcined ceramic powder is made by blending a precursor powder with a form of carbon such as carbon black and heating the blend in an oxygenated atmosphere. The carbon acts as a separator, preventing coalescence of the percursor powder during the calcining process. The blend is characterized by the presence of interstitial spacing between the particles of the carbon powder and the precursor powder. The carbon is eventually oxidized to carbon dioxide and/or carbon monoxide and volatilizes as such, leaving behind the calcined ceramic powder. In a preferred embodiment, the heating is effected by microwave radiation. The carbon absorbs the microwave radiation, heating up the precursor powder and calcining it to form the ceramic powder. Once all the carbon has been oxidized, no more microwave radiation is absorbed, and the heating stops, making the process self-limiting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.