Method of making sodium beta-alumina powder and sintered articles
US4052538A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1976 |
| Grant date | Oct 4, 1977 |
| Priority date | — |
| Expiry date | Apr 19, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In a preferred embodiment a sintered sodium beta-alumina article is made by forming an aqueous acidic colloidal solution (sol) of a dispersible alpha-alumina monohydrate, adding an aqueous solution of an inorganic oxygen-containing sodium salt to the sol to form a thixotropic gel in which the molar ratio of alumina to sodium oxide is in the range of 5 to 11, spray drying the gel to form a free flowing powder, pressing the powder into an article of predetermined shape, heating the pressed article to drive off volatile material, and then sintering the article at a temperature to form a densified sodium beta-alumina structure. When desired, water soluble oxygen-containing inorganic salts of metals such as lithium or magnesium may be added to the sol to form a modified (doped) sodium beta-alumina composition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.