US4507224A
Expired / Lapsed
US
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Ceramics containing fibers of silicon carbide
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1983-11-30
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Granted: 1985-03-26
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Expires: 2003-11-30
Abstract
Abstract Ceramics incorporating fibrous crystals of silicon carbide, optionally, in combination with an electroconductive substance have high electroconductivity and are amenable to electric discharge machining.
Inventors
- 👤 Yasuo Toibana
- 👤 Kazuo Ueno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:56
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/14; H01B1/18; C; C04; C04B; C04B35/00; C04B35/01; C04B35/03; C04B35/04; C04B35/053; C04B35/10; C04B35/111; C04B35/117; C04B35/26; C04B35/2666; C04B35/2675; C04B35/42; C04B35/44; C04B35/443; C04B35/48; C04B35/486; C04B35/488; C04B35/515; C04B35/58; C04B35/584; C04B35/593; C04B35/622; C04B35/64; C04B35/645; C04B35/71; C04B35/78; C04B35/80; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3205; C04B2235/3206; C04B2235/3217; C04B2235/3224; C04B2235/3225; C04B2235/3231; C04B2235/3244; C04B2235/38; C04B2235/3817; C04B2235/3821; C04B2235/3826; C04B2235/3839; C04B2235/3843; C04B2235/3852; C04B2235/3873; C04B2235/3886; C04B2235/50; C04B2235/52; C04B2235/5208; C04B2235/5216; C04B2235/524; C04B2235/5244; C04B2235/526; C04B2235/5264; C04B2235/5276; C04B2235/54; C04B2235/5418; C04B2235/5436; C04B2235/5445; C04B2235/5463; C04B2235/70; C04B2235/74; C04B2235/77; C04B2235/96; C04B2235/963; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12576; Y10T428/12583; Y10T428/1259
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
104 words
A silicon carbide-containing ceramic article of specific resistance not exceeding 10 Ω·cm, using as matrix phase thereof one member selected from the group consisting of alumina, zirconia, magnesia, ferrites, uranium oxide, thorium oxide, MgAl 2 O 4 , NiFeO 4 , NiCrO 4 , MgFe 2 O 4 , LaCrO 3 , LaSrCrO 3 and SrZrO 3 , and having dispersed in said matrix phase fibrous crystals of silicon carbide 10 to 500 μm in length and 0.1 to 10 μm in diameter in an amount falling in the range of 5 to 50% by weight based on the combined amount of the composite.
Claim 2
Dependent Claim
104 words
A silicon carbide-containing ceramic article of specific resistance not exceeding 10 Ω·cm, using as matrix phase thereof one member selected from the group consisting of alumina, zirconia, magnesia, ferrites, uranium oxide, thorium oxide, MgAl 2 O 4 , NiFeO 4 , NiCrO 4 , MgFe 2 O 4 , LaCrO 3 , LaSrCrO 3 and SrZrO 3 , and having dispersed in said matrix phase fibrous crystals of silicon carbide 10 to 500 μm in length and 0.1 to 10 μm in diameter in an amount falling in the range of 5 to 50% by weight based on the combined amount of the composite.
Claim 3
Dependent Claim
24 words
The silicon carbide-containing ceramic article according to claim 1, wherein said fibrous crystals of silicon carbide have a length of 50 to 500 μm.
Claim 4
Dependent Claim
24 words
The silicon carbide-containing ceramic article according to claim 1, wherein said fibrous crystals of silicon carbide have a diameter of 0.5 to 3 μm.
Claim 5
Dependent Claim
37 words
The silicon carbide-containing ceramic article according to claim 1, wherein said fibrous crystals of silicon carbide are incorporated as dispersed in an amount of 10 to 40% by weight based on the combined amount of the composite.
Claim 6
Dependent Claim
172 words
A silicon carbide-containing ceramic article of specific resistance not exceeding 10 Ω·cm, using as matrix phase thereof one member selected from the group consisting of alumina, zirconia, magnesia, ferrites, uranium oxide, thorium oxide, MgAl 2 O 4 , NiFeO 4 , NiCrO 4 , MgFe 2 O 4 , LaCrO 3 , LaSrCrO 3 and SrZrO 3 , silicon nitride, aluminum nitride, boron nitride, silicon carbide, boron carbide and titanium carbide, and having dispersed in said matrix phase fibrous crystals of silicon carbide 10 to 500 μm in length and 0.1 to 10 μm in diameter in an amount falling in the range of 5 to 50% by weight, and a powder of at least one electroconductive compound selected from the group consisting of SiC, TiC, ZrC, B 4 C, WC, HfC, TaC, NbC, TiN, TaN, ZrN, NbN, VN, TiB 2 , ZrB 2 , HfB 2 and TaB 2 in an amount falling in the range of 2 to 20% by weight, respectively based on the combined amount of the composite.
Claim 7
Dependent Claim
172 words
A silicon carbide-containing ceramic article of specific resistance not exceeding 10 Ω·cm, using as matrix phase thereof one member selected from the group consisting of alumina, zirconia, magnesia, ferrites, uranium oxide, thorium oxide, MgAl 2 O 4 , NiFeO 4 , NiCrO 4 , MgFe 2 O 4 , LaCrO 3 , LaSrCrO 3 and SrZrO 3 , silicon nitride, aluminum nitride, boron nitride, silicon carbide, boron carbide and titanium carbide, and having dispersed in said matrix phase fibrous crystals of silicon carbide 10 to 500 μm in length and 0.1 to 10 μm in diameter in an amount falling in the range of 5 to 50% by weight, and a powder of at least one electroconductive compound selected from the group consisting of SiC, TiC, ZrC, B 4 C, WC, HfC, TaC, NbC, TiN, TaN, ZrN, NbN, VN, TiB 2 , ZrB 2 , HfB 2 and TaB 2 in an amount falling in the range of 2 to 20% by weight, respectively based on the combined amount of the composite.
Claim 8
Dependent Claim
24 words
The silicon carbide-containing ceramic article according to claim 5, wherein said fibrous crystals of silicon carbide have a length of 50 to 500 μm.
Claim 9
Dependent Claim
24 words
The silicon carbide-containing ceramic article according to claim 5, wherein said fibrous crystals of silicon carbide have a diameter of 0.5 to 3 μm.
Claim 10
Dependent Claim
37 words
The silicon carbide-containing ceramic article according to claim 5, wherein said fibrous crystals of silicon carbide are incorporated as dispersed in an amount of 10 to 40% by weight based on the combined amount of the composite.
Claim 11
Dependent Claim
43 words
The silicon carbide-containing ceramic article according to claim 5, wherein the combined amount of said fibrous crystals of silicon carbide and said powder of at least one electroconductive compound is at most 70% by weight based on the combined amount of the composite.
Claim 12
Dependent Claim
32 words
The silicon carbide-containing ceramic article according to claim 5, wherein said powder of at least one electroconductive compound is selected from the group consisting of SiC, TiN, TiC and B 4 C.
Claim 13
Dependent Claim
29 words
The silicon carbide-containing ceramic article according to claim 5, wherein said powder of at least one electroconductive compound is a different material from the material of said matrix phase.
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) | 1988-03-25 | 1988-09-24 | 1989-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-25 | 1992-09-24 | 1993-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-25 | 1996-09-24 | 1997-03-26 | $7700.00 | Window Closed / Lapsed |