US5137665A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for densification of titanium diboride
Assignee: Global Tungsten and Powders LLC
•
Filing: 1990-10-18
•
Granted: 1992-08-11
•
Expires: 2010-10-18
Abstract
Abstract In a process for producing a high density article of titanium diboride, a titanium diboride powder mixture is formed into a compact shape, and then sintered according to a two step sintering process with one step being at a low furnace pressure to close the surface porosity of the compact and the second sintering step being at a higher over pressure to form a high density article.
Inventors
- 👤 Christopher A. Tarry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:08
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/5805; C04B35/58064; C04B35/58071; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/64; C04B35/645
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
125 words
A process for producing a high density article of titanium diboride comprising providing a powder mixture, said powder mixture comprising titanium diboride and suitable densification aids and grain growth inhibitors, forming said powder into a compact shape, sintering said compact in a furnace at a temperature from about 1800 degrees Centigrade to 2100 degrees Centigrade at a furnace pressure of from about vacuum to about 0.3 MPa (30 psig) in a sintering atmosphere of an inert gas for a sufficient period of time to close the surface porosity of said compact, increasing said furnace pressure to about 1 to 10 MPa (130 to 1460 psig) and further sintering said compact for a sufficient period of time to form a high density article titanium of diboride.
Claim 2
Dependent Claim
125 words
A process for producing a high density article of titanium diboride comprising providing a powder mixture, said powder mixture comprising titanium diboride and suitable densification aids and grain growth inhibitors, forming said powder into a compact shape, sintering said compact in a furnace at a temperature from about 1800 degrees Centigrade to 2100 degrees Centigrade at a furnace pressure of from about vacuum to about 0.3 MPa (30 psig) in a sintering atmosphere of an inert gas for a sufficient period of time to close the surface porosity of said compact, increasing said furnace pressure to about 1 to 10 MPa (130 to 1460 psig) and further sintering said compact for a sufficient period of time to form a high density article titanium of diboride.
Claim 3
Dependent Claim
32 words
A process for producing a high density article of titanium diboride according to claim 1 wherein said powder mixture consists essentially of at least about 80 percent by weight of titanium diboride.
Claim 4
Dependent Claim
40 words
A process for producing a high density article of titanium diboride according to claim 2 wherein said powder mixture additionally consists essentially of from about 2 to about about 20 percent by weight of densification aids and grain growth inhibitors.
Claim 5
Dependent Claim
36 words
A process for producing a high density article of titanium diboride according to claim 1 wherein the final sintered article has a density ranging from about 96 percent to about 100 percent of the theoretical density.
Claim 6
Dependent Claim
32 words
A process for producing a high density article of titanium diboride according to claim 4 wherein the final sintered article has a density greater than about 98 percent of the theoretical density.
Claim 7
Dependent Claim
34 words
A process for producing a high density article of titanium diboride according to claim 4 wherein the final sintered article has at least one section whose smallest dimension is greater than about 10 mm.
Claim 8
Dependent Claim
37 words
A process for producing a high density article of titanium diboride according to claim 4 wherein the compact is coated or embedded in a powder mixture prior to sintering to reduce the decomposition and enhance the densification.
Claim 9
Dependent Claim
32 words
A process for producing a high density article of titanium diboride according to claim 7 wherein said bedding powders consist essentially of carbides, nitrides and borides of refractory metals and mixtures thereof.
Claim 10
Dependent Claim
22 words
A process for producing a high density article of titanium diboride according to claim 7 wherein said bedding powder comprises boron nitride.
Claim 11
Dependent Claim
22 words
A process for producing a high density article of titanium diboride according to claim 7 wherein said bedding powder comprises titanium carbide.
Claim 12
Dependent Claim
28 words
A process for producing a high density article of titanium diboride according to claim 7 wherein said bedding powder comprises a mixture of boron nitride and titanium carbide.
Claim 13
Dependent Claim
44 words
A process for producing a high density article of titanium diboride according to claim 7 wherein, prior to sintering, said compact is heated in a vacuum at a suitable temperature for a sufficient period of time to remove volatile materials contained in the compact.
Claim 14
Dependent Claim
32 words
A process for producing a high density article of titanium diboride according to claim 12 wherein said heating in a vacuum is at a temperature of from 1000 to 1400 degrees Centigrade.
Claim 15
Dependent Claim
34 words
A process for producing a high density article of titanium diboride according to claim 13 wherein said sintering atmosphere of an inert gas comprises helium, hydrogen, carbon monoxide, carbon dioxide, argon and mixtures thereof.
Claim 16
Dependent Claim
37 words
A process for producing a high density article of titanium diboride according to claim 13 wherein said compact is sintered for a period of time from one to four hours to close the porosity of the surface.
Claim 17
Dependent Claim
51 words
A process for producing a high density article of titanium diboride according to claim 15 wherein the first sintering step is followed by a second sintering step, during said second sintering step the compact is sintered at an over pressure of from about 1.5 to 2.0 MPa (200 to 280 psig.)
Claim 18
Dependent Claim
30 words
A process for producing a high density article of titanium diboride according to claim 1 wherein sintering times during said second sintering are from about 1 to about 10 hours.
Claim 19
Dependent Claim
32 words
A process for producing a high density article of titanium diboride according to claim 1 wherein the heating temperature during the second sintering step is from about 1800 to 2100 degrees Centigrade.
References Cited (Backward Citations)
US3562371A
Cited
US3853973A
Cited
US4007251A
Cited
US4246027A
Cited
US4259119A
Cited
US4292081A
Cited
US4929065A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |