Method of converting PCA to sapphire and converted article
US8157912B2 · kind B2 · utility
12Cited by
11References
14Claims
0Family size
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Key dates
| Filing date | Sep 11, 2007 |
| Grant date | Apr 17, 2012 |
| Priority date | — |
| Expiry date | Feb 15, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/6588
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Polycrystalline alumina (PCA) that has been doped with magnesium oxide is converted to sapphire by additionally doping the PCA with boron oxide and sintering to induce abnormal grain growth. The boron oxide may be added to an already formed green PCA ceramic shape by applying an aqueous boric acid solution to the green ceramic and heating the green ceramic in air to convert the boric acid to boron oxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.