Patent US3899340A successfully refreshed from Google Patents.
US3899340A
Expired / Lapsed
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High elastic modulus glass-ceramic articles
Assignee: Corning Glass Works
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Filing: 1973-11-29
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Granted: 1975-08-12
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Expires: 1993-11-29
Abstract
Abstract The present invention is concerned with the production of glassceramic articles having compositions within the MgO-Al2O3-B2O3 field with, optionally, the inclusion of certain well-known high field strength modifiers, which exhibit elastic moduli in excess of 18 X 106 psi and, frequently, in excess of 22 X 106 psi. In general, the articles will consist essentially, by weight on the oxide basis, of about 5-25% MgO, 10-45% Al2O3, and 20-45% B2O3. The highest elastic moduli are achieved where at least 5% by weight of a high field strength modifier is also included in the composition.
Inventors
- 👤 Joseph W Malmendier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:07
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/0054
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
69 words
A GLASS-CERAMIC ARTICLE DEMONSTRATING AN ELASTIC MODULUS GREATER THAN ABOUT 18X106 PSI CONSISTING ESSENTIALLY OF CRYSTALS OF ALUMINOBORATE AND/OR MAGNESIUM BORATE SOLID SOLUTIONS HOMOGENOUSLY DISPERSED IN A GLASSY MATRIX, WHICH CRYSTALS COMPRISE AT LEAST 75% BY VOLUME OF SAID ARTICLE, THE COMPOSITION OF SAID ARTICLE BEING SUBSTANTIALLY THE SAME THROUGHOUT AND CONSISTING ESSENTIALLY, BE WEIGHT ON THE OXIDE BASIS, OF ABOUT 5-25% MGO, 10-45% AL2O3, AL2O3, AND 20-45% B2O3.
Claim 2
Dependent Claim
69 words
A GLASS-CERAMIC ARTICLE DEMONSTRATING AN ELASTIC MODULUS GREATER THAN ABOUT 18X106 PSI CONSISTING ESSENTIALLY OF CRYSTALS OF ALUMINOBORATE AND/OR MAGNESIUM BORATE SOLID SOLUTIONS HOMOGENOUSLY DISPERSED IN A GLASSY MATRIX, WHICH CRYSTALS COMPRISE AT LEAST 75% BY VOLUME OF SAID ARTICLE, THE COMPOSITION OF SAID ARTICLE BEING SUBSTANTIALLY THE SAME THROUGHOUT AND CONSISTING ESSENTIALLY, BE WEIGHT ON THE OXIDE BASIS, OF ABOUT 5-25% MGO, 10-45% AL2O3, AL2O3, AND 20-45% B2O3.
Claim 3
Dependent Claim
58 words
A glass-ceramic article according to claim 1 wherein said composition also contains up to 50% by weight of a high field strength modifier selected from the group in the indicated proportion of 0-10% TiO2, 0-40% Ta2O5, 0-50% La2O5, 0-25% CeO2, 0-10% ZrO2, 0-35% Y2O3, and 0-15% BeO, the total MgO + BeO not exceeding about 25% by weight.
Claim 4
Dependent Claim
22 words
A glass-ceramic article according to claim 2 wherein said composition contains at least 5% by weight of said high field strength modifiers.
Claim 5
Independent Claim
132 words
A method for making a glass-ceramic article demonstrating an elastic modulus greater than about 18 X 106 psi consisting essentially of crystals of aluminoborate and/or magnesium borate solid solutions homogeneously dispersed in a glassy matrix, said crystals constituting at least 75% by volume of said article, which comprises the steps of: a. melting a batch for a glass consisting essentially, by weight on the oxide basis, of about 5-25% MgO, 10-45% Al2O3, and 20-45% B2O3; b. simultaneously cooling the melt below the transformation range thereof and shaping a glass body therefrom; c. thereafter subjecting said glass body to a temperature above the transformation range but below about 900*C. for a period of time sufficient to crystallize said glass body in situ throughout; and then d. cooling the crystallized body to room temperature.
Claim 6
Independent Claim
132 words
A method for making a glass-ceramic article demonstrating an elastic modulus greater than about 18 X 106 psi consisting essentially of crystals of aluminoborate and/or magnesium borate solid solutions homogeneously dispersed in a glassy matrix, said crystals constituting at least 75% by volume of said article, which comprises the steps of: a. melting a batch for a glass consisting essentially, by weight on the oxide basis, of about 5-25% MgO, 10-45% Al2O3, and 20-45% B2O3; b. simultaneously cooling the melt below the transformation range thereof and shaping a glass body therefrom; c. thereafter subjecting said glass body to a temperature above the transformation range but below about 900*C. for a period of time sufficient to crystallize said glass body in situ throughout; and then d. cooling the crystallized body to room temperature.
Claim 7
Dependent Claim
58 words
A method according to claim 4 wherein said glass body also contains up to 50% by weight of a high field strength modifier selected from the group in the indicated proportion of 0-10% TiO2, 0-40% Ta2O5, 0-50% La2O5, 0-25% CeO2, 0-10% ZrO2, 0-35% Y2O3, and 0-15% BeO, the total MgO + BeO not exceeding about 25% by weight.
Claim 8
Dependent Claim
22 words
A method according to claim 5 wherein said glass body contains at least 5% by weight of said high field strength modifiers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |