US3725091A
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Glass-ceramic metal cermets and method
Assignee: Corning Glass Works
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Filing: 1971-04-12
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Granted: 1973-04-03
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Expires: 1991-04-12
Abstract
Abstract A glass-ceramic metal cermet comprising a glass-ceramic phase consisting essentially of crystals of Beta -quartz, cordierite, mullite, or calcium aluminate uniformly distributed throughout a glassy matrix and a metal phase consisting essentially of a metal selected from the group consisting of W, Mo, W-Mo alloys and WMo-Cr alloys.
Inventors
- 👤 C Chyung
- 👤 H Rittler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:12
CPC Classifications
C; C22; C22C; C22C29/00; C22C29/12; C03; C03C; C03C10/00; C03C10/0018; C03C10/0027; C03C10/0036; C03C10/0045
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
23 words
A cermet according to claim 1 wherein the glass-ceramic phase has a coefficient of thermal expansion ranging between about 30-90 X 10 7/*C.
Claim 2
Dependent Claim
24 words
A cermet according to claim 2 wherein the metallic phase consists essentially in weight percent, of about 0-100% Mo, 0-100% W and 0-50% Cr.
Claim 3
Dependent Claim
33 words
A cermet according to claim 3 wherein the metallic phase consists essentially of 70-90% Mo and 10-30% Cr, forms a three-dimensionally continuous network throughout the cer-met and comprises about 25-50% by volume thereof.
Claim 4
Dependent Claim
76 words
A cermet according to claim 3 wherein the glass-ceramic phase consists essentially of crystals of Beta -quartz solid solution evenly dispersed throughout a glassy matrix and comprising a major proportion of the phase, said phase being produced by the in situ crystallization of a glass consisting essentially, in weight percent on the oxide basis as calculated from the batch, of about 60-70% SiO2, 17-25% Al2O3, 9-15% MgO, 1-3% Li2O, 0-8% ZrO2, 0-6% TiO2 and 2-10% TiO2+ZrO2.
Claim 5
Dependent Claim
104 words
A cermet according to claim 3 wherein the glass-ceramic phase consists essentially of crystals of cordierite solid solution evenly dispersed throughout a glassy matrix and comprising a major proportion of the phase, said phase being produced by the in situ crystallization of a glass consisting essentially, in weight percent on the oxide basis as calculated from the batch, of about 45-55% SiO2, 27-37% Al2O3, 11-16% MgO and a nucleating agent selected in the indicated proportion from the group consisting of 0.5-2% Si and 2-12% TiO2, wherein ZrO2 may be substituted for TiO2 in amounts ranging up to about 5 percent on a weight-for-weight basis.
Claim 6
Dependent Claim
64 words
A cermet according to claim 3 wherein the glass-ceramic phase consists essentially of mullite crystals evenly dispersed throughout a glassy matrix and comprising a major proportion of the phase, said phase being produced by the in situ crystallization of a glass consisting essentially, in weight percent on the oxide basis as calculated from the batch, of about 45-55% SiO2, 35-45% Al2O3, and 5-15% BaO.
Claim 7
Dependent Claim
69 words
A cermet according to claim 3 wherein the glass-ceramic phase consists essentially of calcium aluminate crystals evenly dispersed throughout a glassy matrix and comprising a major proportion of the phase, said phase being produced by the in situ crystallization of a glass consisting essentially, in weight percent on the oxide basis as calculated from the batch, of about 32-45% CaO, 35-50% Al2O3, 5-10% MgO, 5-10% BaO and 6-15% ZrO2.
Claim 8
Independent Claim
203 words
A method of making a glass-ceramic metal cermet comprising the steps of: a. mixing a finely-divided thermally crystallizable glass with finely-divided metals selected from the group consisting of Mo, W and Cr to form a homogeneous mixture, said metals being convertible into a metallic phase comprising about 20-60% by volume of the mixture upon sintering and consisting essentially in weight percent of about 0-100% Mo, 0-100% W and 0-50% Cr, and said glass being thermally crystallizable in situ to yield a glass-ceramic having a coefficient of thermal expansion ranging between about 30-90 X 10 7/*C. wherein a crystalline species selected from the group consisting of Beta -quartz solid solution, cordierite solid solution, mullite and calcium aluminate constitutes the principal crystalline phase; b. forming said homogeneous mixture into a compact; c. sintering the compact at temperatures ranging from about 100-200*C. above the liquidus temperature of said principal crystalline phase in said thermally crystallizable glass; d. rapidly cooling the compact to at least the nucleating temperature of said thermally crystallizable glass, and e. thereafter subjecting the compact to a crystallization heat treatment to cause the development of crystal nuclei evenly throughout the glassy phase and the subsequent development of the desired degree of crystallization therein.
Claim 9
Dependent Claim
29 words
The method of claim 9 wherein the crystallization heat treatment comprises heating the cermet to a temperature ranging from about 700*-1300*C. for a time ranging from about 1-8 hours.
Claim 10
Dependent Claim
48 words
The method of claim 10 wherein the crystallization heat treatment comprises heating the cermet to a temperature ranging from about 700*-800*C. for a time ranging from about 1-4 hours, and thereafter heating it to a temperature ranging from about 900*-1300*C. for a time ranging from about 1-4 hours.
Claim 11
Dependent Claim
16 words
The method of claim 11 wherein the compact is sintered at temperatures ranging from about 1300*-1550*C.
References Cited (Backward Citations)
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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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |