Strengthening ceramic articles
Abstract
Abstract THIS INVENTION RELATES TO THE CHEMICAL STRENGTHENING OF SINTERED CERAMIC ARTICLES OF HIGH ALUMINA COMPOSITIONS. THE PROCESS OF THE INVENTION COMPRISES CONTACTING A SINTERED ARTICLE CONSISTING ESSENTIALLY, BY WEIGHT, OF ABOUT 50-70% ALUMINA AND 26-50%L NEPHELINE SYENTITE, THE TOTAL OF THE ALUMINA AND NEPHELINE SYENITE CONSTITUTING ABOUT 88-100% OF THE ARTICLE, 0-10% KAOLINITIC CLAY, AND 0-2% OF A MINERALIZER, WITH AN EXTERNALL SOURCE OF POTASSIUM IONS SUCH THAT THE POTASSIUM IONS DIFFUSE INOT A SURFACE LAYER WITHIN THE ARTICLE, REPLACING SODIUM IONS ORIGINALLY PRESENT THEREIN, AND THEREBY CAUSING COMPRESSIVE STRESSES TO BE SET UP IN THE SURFACE LAYER RESULTING IN AN INCREASE IN THE MECHANICAL STRENGTH OF THE ARTICLE WHICH, IN SOME INSTANCES, IS MORE THAN TWICE THAT OF THE UNTREATED ARTICLE.
Inventors
- 👤 John E Megles
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |