Method for preparing dense, beta-alumina ceramic bodies by liquid phase sintering
US4138455A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1977 |
| Grant date | Feb 6, 1979 |
| Priority date | — |
| Expiry date | Apr 15, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for preparing a dense, B"-alumina-containing ceramic body exhibiting an electrical resistivity for sodium ion conduction at 300.degree. C. between about 3 and about 20 ohm-cm, by sintering a green ceramic body formed from a composition comprising at least about 90 weight percent of aluminum oxide, about 8.7 to 9.4 weight percent of sodium oxide, about 0.7-0.9 weight percent of lithium oxide, and from 0.0 to about 4.0 weight percent of magnesium oxide at a temperature between about 1400.degree. C. and about 1600.degree. C., for between about three (3) minutes and about 180 minutes to obtain a body containing both B and B"-alumina crystalline forms. The sintered body exhibits a density greater than 90% of theoretical for polycrystalline B"-alumina and a uniform grain size between about 20 and 100 micrometers. All of these compositions were prepared by using either a binary liquid forming mixture between sodium aluminate (NaAlO.sub.2) and lithium aluminate (LiAlO.sub.2), a ternary liquid forming mixture between sodium aluminate, lithium aluminate and B"-Al.sub.2 O.sub.3, or a ternary liquid forming ingredient between magnesium aluminate (MgAl.sub.2 O.sub.4), sodi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.