US4554197A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fiber reinforced glass/glass-ceramic mirror blanks
Assignee: Corning Glass Works
•
Filing: 1984-06-18
•
Granted: 1985-11-19
•
Expires: 2004-06-18
Abstract
Abstract This invention relates to the production of mirror blanks comprising a low expansion graphite or SiC fiber reinforced glass-ceramic composite substrate with a surface facing of a glass or glass-ceramic bonded thereto having an expansion closely matching that of the composite.
Inventors
- 👤 Kenneth Chyung
- 👤 Peter C. Schultz
- 👤 Mark P. Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:20
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/02; B32B5/12; B32B5/22; B32B5/24; B32B5/26; B32B9/00; B32B9/005; B32B9/04; B32B9/047; C; C03; C03C; C03C10/00; C03C10/0018; C03C10/0027; C03C10/0036; C03C10/0045; C03C14/00; C03C14/002; G; G02; G02B; G02B5/00; G02B5/08; B32B2307/00; B32B2307/40; B32B2307/412; B32B2309/00; B32B2309/02; C03C2214/00; C03C2214/02; C03C2214/20; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24058; Y10T428/24124; Y10T428/249921; Y10T428/249924; Y10T428/249928; Y10T428/249929; Y10T428/30
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
38 words
A mirror blank comprising a laminate consisting of a low expansion graphite or SiC fiber/glass-ceramic composite substrate and a mirror surface facing of a glass or glass-ceramic bonded thereto having an expansion closely matching that of said substrate.
Claim 2
Dependent Claim
38 words
A mirror blank comprising a laminate consisting of a low expansion graphite or SiC fiber/glass-ceramic composite substrate and a mirror surface facing of a glass or glass-ceramic bonded thereto having an expansion closely matching that of said substrate.
Claim 3
Dependent Claim
21 words
A mirror blank according to claim 1 wherein said graphite or SiC fiber comprises about 30-70% by volume of said composite.
Claim 4
Dependent Claim
30 words
A mirror blank according to claim 1 wherein said glass-ceramic of said composite has a base composition in the general system Li 2 O-Al 2 O 3 -SiO 2 .
Claim 5
Dependent Claim
19 words
A mirror blank according to claim 3 wherein said glass-ceramic contains beta-quartz solid solution as the predominant crystal phase.
Claim 6
Dependent Claim
56 words
A mirror blank according to claim 3 wherein said glass-ceramic consists essentially, in weight percent on the oxide basis, of about ______________________________________
Li.sub.2 O
1-5 ZnO 0-13 ZrO.sub.2
0-2.5
Al.sub.2 O.sub.3
17-24 Na.sub.2 O
0-2 Cs.sub.2 O
0-5
SiO.sub.2
60-68 K.sub.2 O
0-3 BaO 0-4
MgO 0.5-3 TiO.sub.2
0-4.5 Nb.sub.2 O.sub.5
0-5
As.sub.2 O.sub.3
0-1
______________________________________
Claim 7
Dependent Claim
16 words
A mirror blank according to claim 1 wherein said surface facing consists of fused silica glass.
Claim 8
Dependent Claim
19 words
A mirror blank according to claim 1 wherein said surface facing consists of a low expansion, fused titania-silica glass.
Claim 9
Dependent Claim
25 words
A mirror blank according to claim 1 wherein said surface facing consists of a transparent glass-ceramic containing beta-quartz solid solution as the predominant crystal phase.
Claim 10
Dependent Claim
30 words
A mirror blank according to claim 1 wherein said graphite or SiC fibers are present in alternating orientations to minimize the anisotropy of the physical properties exhibited by the composite.
Claim 11
Dependent Claim
19 words
A mirror blank according to claim 1 wherein said fibers comprise about 30-70% by volume of said composite substrate.
Claim 12
Independent Claim
210 words
A method for making a mirror blank comprising a laminate consisting of a graphite or SiC fiber/glass-ceramic composite substrate and a mirror surface facing of a glass or glass-ceramic bonded thereto which comprises the steps of: (a) preparing unidirectional prepregs in sheet form consisting of graphite or SiC fibers, an organic binder, and glass powder having a base composition within the general Li 2 O-Al 2 O 3 -SiO 2 composition system; (b) stacking said prepregs; (c) burning out said binder in a non-oxidizing atmosphere; (d) placing a low expansion transparent glass, glass-ceramic, or precursor glass for a low expansion glass-ceramic plate into contact with a face of said stack of prepregs; (e) exposing said stack of prepregs with said transparent glass, glass-ceramic, or precursor glass for a glass-ceramic plate in contact therewith to a non-oxidizing atmosphere at a temperature and for a time sufficient to consolidate said stack into an integral composite body and to bond said plate to said composite body, thereby forming a laminate; (f) exposing said laminate in a non-oxidizing atmosphere to a temperature and for a time sufficient to cause said composite body and, where present, said precursor glass to crystallize in situ to a glass-ceramic containing beta-quartz solid solution as the predominant crystal phase.
Claim 13
Independent Claim
210 words
A method for making a mirror blank comprising a laminate consisting of a graphite or SiC fiber/glass-ceramic composite substrate and a mirror surface facing of a glass or glass-ceramic bonded thereto which comprises the steps of: (a) preparing unidirectional prepregs in sheet form consisting of graphite or SiC fibers, an organic binder, and glass powder having a base composition within the general Li 2 O-Al 2 O 3 -SiO 2 composition system; (b) stacking said prepregs; (c) burning out said binder in a non-oxidizing atmosphere; (d) placing a low expansion transparent glass, glass-ceramic, or precursor glass for a low expansion glass-ceramic plate into contact with a face of said stack of prepregs; (e) exposing said stack of prepregs with said transparent glass, glass-ceramic, or precursor glass for a glass-ceramic plate in contact therewith to a non-oxidizing atmosphere at a temperature and for a time sufficient to consolidate said stack into an integral composite body and to bond said plate to said composite body, thereby forming a laminate; (f) exposing said laminate in a non-oxidizing atmosphere to a temperature and for a time sufficient to cause said composite body and, where present, said precursor glass to crystallize in situ to a glass-ceramic containing beta-quartz solid solution as the predominant crystal phase.
Claim 14
Dependent Claim
23 words
A method according to claim 11 wherein said fibers are in an orientation selected from the group of 0°/0°, 0°/90°, 0°/±45°/90°, and 0°/±60°.
Claim 15
Dependent Claim
24 words
A method according to claim 11 wherein said low expansion glass is selected from the group of fused silica and a fused titania-silica composition.
Claim 16
Dependent Claim
20 words
A method according to claim 11 wherein said low expansion glass-ceramic contains beta-quartz solid solution as the predominant crystal phase.
Claim 17
Dependent Claim
56 words
A method according to claim 11 wherein said glass powder consists essentially, in weight percent on the oxide basis, of about ______________________________________
SiO.sub.2
60-68 ZnO 0-13 ZrO.sub.2
0-2.5
Al.sub.2 O.sub.3
17-24 Na.sub.2 O
0-2 Cs.sub.2 O
0-5
Li.sub.2 O
1-5 K.sub.2 O
0-3 BaO 0-4
MgO 0.5-3 TiO.sub.2
0-4.5 Nb.sub.2 O.sub.5
0-5
As.sub.2 O.sub.3
0-1
______________________________________
Claim 18
Dependent Claim
17 words
A method according to claim 11 wherein said fibers comprise about 30-70% by volume of said composite.
Claim 19
Dependent Claim
32 words
A method according to claim 11 wherein said temperature to consolidate said stack into an integral composite body and to bond said plate to said composite body ranges between about 950°-1400° C.
Claim 20
Dependent Claim
29 words
A method according to claim 11 wherein said temperature to cause said composite body and, where present, said precursor glass to crystallize in situ ranges between about 850°-1100° C.
Claim 21
Dependent Claim
15 words
A method according to claim 11 wherein said consolidation is carried out by hot pressing.
Claim 22
Independent Claim
253 words
A method for making a mirror blank comprising a laminate consisting of a graphite or SiC fiber/glass-ceramic composite substrate and a mirror surface of a glass or glass-ceramic bonded thereto which comprises the steps of: (a) preparing unidirectional prepregs in sheet form consisting of graphite or SiC fibers, an organic binder, and glass powder having a base composition within the general Li 2 O-Al 2 O 3 -SiO 2 composition system; (b) stacking said prepregs; (c) burning out said binder in a non-oxidizing atmosphere; (d) exposing said stack of prepregs to a non-oxidizing atmosphere at a temperature for a time sufficient to consolidate said stack into an integral composite body. (e) exposing said composite body to a non-oxidizing atmosphere at a temperature and for a time sufficient to cause said body to crystallize in situ to a glass-ceramic containing beta-quartz solid solution as the predominant crystal phase; (f) placing a low expansion transparent glass, glass-ceramic, or precursor glass for a low expansion glass-ceramic plate into contact with a face of said composite body; (g) exposing said composite body with said transparent glass, glass-ceramic, or precursor glass for a glass-ceramic plate in contact therewith to a temperature and for a time sufficient to bond said plate to said composite body, thereby forming a laminate; and, where said precursor glass is present, (h) exposing said laminate to a temperature and for a time sufficient to cause said precursor glass to crystallize in situ to a glass-ceramic containing beta-quartz solid solution as the predominant crystal phase.
Claim 23
Independent Claim
253 words
A method for making a mirror blank comprising a laminate consisting of a graphite or SiC fiber/glass-ceramic composite substrate and a mirror surface of a glass or glass-ceramic bonded thereto which comprises the steps of: (a) preparing unidirectional prepregs in sheet form consisting of graphite or SiC fibers, an organic binder, and glass powder having a base composition within the general Li 2 O-Al 2 O 3 -SiO 2 composition system; (b) stacking said prepregs; (c) burning out said binder in a non-oxidizing atmosphere; (d) exposing said stack of prepregs to a non-oxidizing atmosphere at a temperature for a time sufficient to consolidate said stack into an integral composite body. (e) exposing said composite body to a non-oxidizing atmosphere at a temperature and for a time sufficient to cause said body to crystallize in situ to a glass-ceramic containing beta-quartz solid solution as the predominant crystal phase; (f) placing a low expansion transparent glass, glass-ceramic, or precursor glass for a low expansion glass-ceramic plate into contact with a face of said composite body; (g) exposing said composite body with said transparent glass, glass-ceramic, or precursor glass for a glass-ceramic plate in contact therewith to a temperature and for a time sufficient to bond said plate to said composite body, thereby forming a laminate; and, where said precursor glass is present, (h) exposing said laminate to a temperature and for a time sufficient to cause said precursor glass to crystallize in situ to a glass-ceramic containing beta-quartz solid solution as the predominant crystal phase.
Claim 24
Dependent Claim
23 words
A method according to claim 20 wherein said fibers are in one orientation selected from the group of 0°/0°, 0°/90°, 0°/±45°/90°, and 0°/±60°.
Claim 25
Dependent Claim
24 words
A method according to claim 20 wherein said low expansion glass is selected from the group of fused silica and a fused titania-silica composition.
Claim 26
Dependent Claim
20 words
A method according to claim 20 wherein said low expansion glass-ceramic contains beta-quartz solid solution as the predominant crystal phase.
Claim 27
Dependent Claim
56 words
A method according to claim 20 wherein said glass powder consists essentially, in weight percent on the oxide basis, of about ______________________________________
SiO.sub.2
60-68 ZnO 0-13 ZrO.sub.2
0-2.5
Al.sub.2 O.sub.3
17-24 Na.sub.2 O
0-2 Cs.sub.2 O
0-5
Li.sub.2 O
1-5 K.sub.2 O
0-3 BaO 0-4
MgO 0.5-3 TiO.sub.2
0-4.5 Nb.sub.2 O.sub.5
0-5
As.sub.2 O.sub.3
0-1
______________________________________
Claim 28
Dependent Claim
17 words
A method according to claim 20 wherein said fibers comprise about 30-70% by volume of said composite.
Claim 29
Dependent Claim
23 words
A method according to claim 20 wherein said temperature to consolidate said stack into an integral composite body ranges between about 950°-1400° C.
Claim 30
Dependent Claim
22 words
A method according to claim 20 wherein said temperature to bond said plate to said composite body ranges between about 950°-1400° C.
Claim 31
Dependent Claim
29 words
A method according to claim 20 wherein said temperature to cause said composite body and, where present, said precursor glass to crystallize in situ ranges between about 850°-1100° C.
Claim 32
Dependent Claim
15 words
A method according to claim 20 wherein said consolidation is carried out by hot pressing.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-18 | 1989-05-20 | 1989-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-18 | 1993-05-20 | 1993-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-18 | 1997-05-20 | 1997-11-19 | $7700.00 | Window Closed / Lapsed |