Patent US4892846A successfully refreshed from Google Patents.
US4892846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reinforceable sintered glass-ceramics
Assignee: National Research Development Corp UK
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Filing: 1988-11-17
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Granted: 1990-01-09
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Expires: 2008-11-17
Abstract
Abstract A fibre-reinforced ceramic material is made by making a melt of glass of specified composition, cooling the melt rapidly enough for it to solidify as a glass, crushing the glass to a particle size not exceeding 70 μm but preferably not exceeding 50 μm mixing the powder with reinforcing fibres and heat-treating the mixture, preferably under pressure. The glass composition is: 100 parts by weight of base glass (0-30 CaO, 0-30 MgO, 5-35 Al 2 O 3 , and 35-75 SiO 2 ) plus 1/2-3 parts Cr 2 O 3 plus 1/2-10 parts of Fe 2 O 3 or the equivalent. This ensures the ceramic contains both surface-nucleated and internally-nucleated crystals, enhancing its properties.
Inventors
- 👤 Philip S. Rogers
- 👤 Rees D. Rawlings
- 👤 Hyung S. Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:32
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/0036; C03C10/0045; C03C14/00; C03C14/002; C03C14/004; C03C2214/00; C03C2214/02; C03C2214/04; C03C2214/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
120 words
A method of making a ceramic material comprising a primary crystalline phase of diopside and about 5 to 30 weight % anorthite, said method comprising the steps of: forming a homogeneous glass powder having a composition in parts by weight: CaO+MgO+Al 2 O 3 +SiO 2 totalling 100 in proportions (0-30):(0-30):(5-35):(35-75) respectively, plus 1/2-3 Cr 2 O 3 or a precursor of Cr 2 O 3 to yield 1/2-3 Cr 2 O 3 , plus 1/2-10 Fe 2 O 3 or a precursor of Fe 2 O 3 to yield 1/2-10 Fe 2 O 3 , and of a particle size not exceeding 70 μm; and heating the powder so as to sinter and crystallize it in the same heating.
Claim 2
Independent Claim
120 words
A method of making a ceramic material comprising a primary crystalline phase of diopside and about 5 to 30 weight % anorthite, said method comprising the steps of: forming a homogeneous glass powder having a composition in parts by weight: CaO+MgO+Al 2 O 3 +SiO 2 totalling 100 in proportions (0-30):(0-30):(5-35):(35-75) respectively, plus 1/2-3 Cr 2 O 3 or a precursor of Cr 2 O 3 to yield 1/2-3 Cr 2 O 3 , plus 1/2-10 Fe 2 O 3 or a precursor of Fe 2 O 3 to yield 1/2-10 Fe 2 O 3 , and of a particle size not exceeding 70 μm; and heating the powder so as to sinter and crystallize it in the same heating.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein the material comprises about 15 to 30 weight % anorthite.
Claim 4
Dependent Claim
13 words
A method according to claim 1, wherein the heating is conducted under pressure.
Claim 5
Dependent Claim
18 words
A method according to claim 1, wherein the particle size of the powder does not exceed 50 μm.
Claim 6
Dependent Claim
37 words
A method according to claim 2, wherein the powder is formed by making a melt of glass of said composition and cooling the melt rapidly enough for it to solidify as a glass, and comminuting the glass.
Claim 7
Dependent Claim
20 words
A method according to claim 5, wherein the comminuting is by granulating by pouring the melt into a quenching medium.
Claim 8
Dependent Claim
20 words
A method according to claim 5, wherein the comminuting is by crushing the cooled glass to the said particle size.
Claim 9
Dependent Claim
20 words
A method according to claim 1, further comprising mixing said crushed glass particles with a reinforcing phase, before the sintering.
Claim 10
Dependent Claim
13 words
A method according to claim 8, wherein the reinforcing phase is a ceramic.
Claim 11
Dependent Claim
17 words
A method according to claim 9, wherein the ceramic is in the form of particles or fibers.
Claim 12
Dependent Claim
25 words
A method according to claim 9, wherein the ceramic is selected from the group consisting of alumina, carbon, silicon carbide, silicon nitride, spinel and zirconia.
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) | 1993-01-08 | 1993-07-10 | 1994-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-08 | 1997-07-10 | 1998-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-08 | 2001-07-10 | 2002-01-09 | $7700.00 | Window Closed / Lapsed |