Patent US4427445A successfully refreshed from Google Patents.
US4427445A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tungsten alloys containing A15 structure and method for making same
Assignee: DART & KRAFT Inc A CORP OF DEL
•
Filing: 1982-07-21
•
Granted: 1984-01-24
•
Expires: 2002-07-21
Abstract
Abstract A hard fine-grained internally stressed material of tungsten and carbon or tungsten, carbon and oxygen is described which is produced by thermochemical deposition. The material consists primarily of a two phase mixture of pure tungsten and an A15 structure, is free of columnar grain distribution, and has a hardness of greater than 1,200 VHN. The average grain size is less than 0.1 micron.
Inventors
- 👤 Robert A. Holzl
- 👤 Robert E. Benander
- 👤 Robert D. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:48
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/32
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
118 words
A thermochemically deposited product consisting primarily of a two phase mixture of tungsten and carbon or tungsten, carbon and oxygen, one phase being pure tungsten and the other phase being an A15 structure, said tungsten phase being present in between about twenty percent and ninety percent, said product having a carbon content in said A15 structure phase by weight greater than about 0.1 percent and less than about 1 percent, said carbon content being substantially less than the carbon content corresponding to an A15 structure consisting of W 3 C, said product being free of columnar distribution of grains, having a hardness of greater than 1200 VHN, and having an average grain size of less than 0.1 microns.
Claim 2
Dependent Claim
118 words
A thermochemically deposited product consisting primarily of a two phase mixture of tungsten and carbon or tungsten, carbon and oxygen, one phase being pure tungsten and the other phase being an A15 structure, said tungsten phase being present in between about twenty percent and ninety percent, said product having a carbon content in said A15 structure phase by weight greater than about 0.1 percent and less than about 1 percent, said carbon content being substantially less than the carbon content corresponding to an A15 structure consisting of W 3 C, said product being free of columnar distribution of grains, having a hardness of greater than 1200 VHN, and having an average grain size of less than 0.1 microns.
Claim 3
Dependent Claim
40 words
A thermochemically deposited product in accordance with claim 1 wherein, upon heat treating at between about 600° C. and 700° C., said A15 structure is transformed and said hardness is maintained to at least half of its pre-heat treated hardness.
Claim 4
Dependent Claim
18 words
A thermochemically deposited product in accordance with claim 1 wherein the A15 phase is internally prestressed in compression.
Claim 5
Dependent Claim
18 words
A thermochemically deposited product in accordance with claim 3 wherein the prestress is in excess of 1000 MPa.
Claim 6
Dependent Claim
28 words
A thermochemically deposited product in accordance with claim 1 wherein the lattice spacing of the A15 phase is substantially less than 5.04A as determined by x-ray diffraction analysis.
Claim 7
Dependent Claim
127 words
A coated substrate product comprising a metal substrate having a coating thereon consisting primarily of a two phase mixture of tungsten and carbon or tungsten can carbon and oxygen, one phase being pure tungsten and the other phase being an A15 structure, said tungsten phase being present in between about twenty percent and ninety percent, said coating having a carbon content in said A15 structure phase by weight greater than about 0.1 percent and less than about 1 percent, said carbon content being substantially less than the carbon content corresponding to an A15 structure consisting of W 3 C, said product being free of columnar distribution of grains, having a hardness of greater than 1200 VHN, and having an average grain size of less than 0.1 microns.
Claim 8
Dependent Claim
127 words
A coated substrate product comprising a metal substrate having a coating thereon consisting primarily of a two phase mixture of tungsten and carbon or tungsten can carbon and oxygen, one phase being pure tungsten and the other phase being an A15 structure, said tungsten phase being present in between about twenty percent and ninety percent, said coating having a carbon content in said A15 structure phase by weight greater than about 0.1 percent and less than about 1 percent, said carbon content being substantially less than the carbon content corresponding to an A15 structure consisting of W 3 C, said product being free of columnar distribution of grains, having a hardness of greater than 1200 VHN, and having an average grain size of less than 0.1 microns.
Claim 9
Dependent Claim
32 words
A coated substrate product in accordance with claim 4 wherein the substrate comprises a ferrous body having a coefficient of thermal expansion of less than 13 micrometers per meter per degree C.
Claim 10
Dependent Claim
17 words
A coated substrate product in accordance with claim 4 wherein the substrate comprises a cemented tungsten carbide.
References Cited (Backward Citations)
US3368914A
Cited
US3574672A
Cited
US3565676A
Cited
US3640689A
Cited
US3814625A
Cited
GB1540718A
Cited
US4147820A
Cited
US4162345A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-23 | 1987-07-25 | 1988-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-23 | 1991-07-25 | 1992-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-23 | 1995-07-25 | 1996-01-24 | $7700.00 | Window Closed / Lapsed |