Glass treatment and glass-ceramic article therefrom
Abstract
Abstract A PROCESS OF TREATING AN ARTICLE OF GLASS TO PROVIDE A GLASS-CERAMIC HAVING A HIGH FLEXURAL STRENGTH WHICH COMPRISES HEAT TREATING AN ARTICLE OF GLASS AT ELEVATED TEMPERATURES, INCLUDING A NUCLEATION TEMPERATURE AND A SUBSEQUENT HIGHER TEMPERATURE THAT IS A MAXIMUM OF 1650* F. FOR PERIODS OF TIME SUFFICIENT TO PROVIDE A GLASS-CERAMIC ARTICLE WITH A COMPRESSIVE LAYER, FOLLOWED BY TREATMENT OF THE ARTICLE OF GLASS-CERAMIC WITH AN ION-EXCHANGE MEDIUM CONTAINING A SALT OF AN ALKALI METAL OTHER THAN LITHIUM AT AN ELEVATED TEMPERATURE OF AT LEAST 200*C. AND FOR A PERIOD OF TIME TO EXCHANGE ALKALI METAL IONS OF THE SALT WITH LITHIUM IONS IN THE GLASS-CERAMIC SURFACE, WITH THE ELEVATED TEMPERATURE BEING BELOW THAT AT WHICH THE COMPRESSIVE STRESS CREATED BY THE ION-EXCHANGE IS RELIEVED, AND THE ARTICLE OF GLASS-CERAMIC RESULTING FROM SAID PROCESS.
Inventors
- 👤 George A Simmons
Bibliographic Details
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |