Patent US5326731A successfully refreshed from Google Patents.
US5326731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic compositions for wear resistant applications
Assignee: Electrofuel Manufacturing Co
•
Filing: 1993-11-18
•
Granted: 1994-07-05
•
Expires: 2013-11-18
Abstract
Abstract A composition for hard, sintered, tough and wear resistant ceramic articles is described. The composition is comprised of alumina, titanium carbonitride and filaments of titanium diboride or titanium nitride. The ceramic articles made of this composition are isostatically hot pressed or sintered at high temperature in inert gas. The density of the ceramic articles is usually in excess of 99% theoretical density and the hardness is greater than 20 GPa. The process was applied to manufacture ceramic cutting inserts of the above composition.
Inventors
- 👤 Rakesh Bhola
- 👤 Sankar Dasgupta
- 👤 James K. Jacobs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:35
CPC Classifications
B; B24; B24D; B24D3/00; B24D3/02; B24D3/04; B24D3/14; B24D3/16; C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/117; C04B35/622; C04B35/64; C04B35/645; C04B35/6455; C04B35/71; C04B35/78; C04B35/80
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
130 words
A composition for a hard, sintered ceramic article, essentially consisting of: 50-80% by volume alumina, 5-40% by volume titanium carbonitride, the nitride and carbide content in said carbonitride being defined such that the fraction C/C+N has a value between 0.1 and 1, 1-30% by volume polycrystalline filaments selected from the group consisting of titanium diboride, titanium nitride and alloys thereof, said filaments having diameters in excess of 4 μm and lengths greater than 150 μm, and a grain growth modifier in less than 0.1 wt. %, selected from the group consisting of magnesia, nickel oxide and cobalt oxide; said hard ceramic article having density in excess of 99% of the theoretical density defined by said composition, subsequent to sintering, and said sintered ceramic article having hardness greater than 20 GPa.
Claim 2
Dependent Claim
130 words
A composition for a hard, sintered ceramic article, essentially consisting of: 50-80% by volume alumina, 5-40% by volume titanium carbonitride, the nitride and carbide content in said carbonitride being defined such that the fraction C/C+N has a value between 0.1 and 1, 1-30% by volume polycrystalline filaments selected from the group consisting of titanium diboride, titanium nitride and alloys thereof, said filaments having diameters in excess of 4 μm and lengths greater than 150 μm, and a grain growth modifier in less than 0.1 wt. %, selected from the group consisting of magnesia, nickel oxide and cobalt oxide; said hard ceramic article having density in excess of 99% of the theoretical density defined by said composition, subsequent to sintering, and said sintered ceramic article having hardness greater than 20 GPa.
Claim 3
Dependent Claim
24 words
A composition for a hard sintered ceramic article as claimed in claim 1, wherein said polycrystalline filament has diameter between 4 and 10 μm.
Claim 4
Dependent Claim
35 words
A composition for a hard, sintered ceramic article as claimed in claim 1, wherein said value of the fraction C/C+N defining said carbide and nitride contained in said titanium carbonitride falls between 0.3 and 0.7.
Claim 5
Dependent Claim
132 words
A sintered ceramic cutting insert having composition essentially consisting of: 50-80% by volume alumina, 5-40% by volume titanium carbonitride, the nitride and carbide content in the carbonitride being defined such that the fraction C/C+N has a value between 0.1 and 1, 1-30% by volume polycrystalline filaments selected from the group consisting of titanium diboride, titanium nitride and alloys thereof, said polycrystalline filaments having diameters in excess of 4 μm and lengths greater than 150 μm, and a grain growth modifier in less than 0.1 wt. %, selected from the group consisting of magnesia, nickel oxide and cobalt oxide; said ceramic cutting insert having density in excess of 99% of the theoretical density defined by said composition, subsequent to sintering, and said sintered ceramic cutting insert having hardness values greater than 20 GPa.
Claim 6
Dependent Claim
132 words
A sintered ceramic cutting insert having composition essentially consisting of: 50-80% by volume alumina, 5-40% by volume titanium carbonitride, the nitride and carbide content in the carbonitride being defined such that the fraction C/C+N has a value between 0.1 and 1, 1-30% by volume polycrystalline filaments selected from the group consisting of titanium diboride, titanium nitride and alloys thereof, said polycrystalline filaments having diameters in excess of 4 μm and lengths greater than 150 μm, and a grain growth modifier in less than 0.1 wt. %, selected from the group consisting of magnesia, nickel oxide and cobalt oxide; said ceramic cutting insert having density in excess of 99% of the theoretical density defined by said composition, subsequent to sintering, and said sintered ceramic cutting insert having hardness values greater than 20 GPa.
Claim 7
Dependent Claim
23 words
A sintered ceramic cutting insert as claimed in claim 4, obtained by sintering in inert gas at a temperature higher than 1500° C.
Claim 8
Dependent Claim
15 words
A sintered ceramic cutting insert as claimed in claim 4, obtained by hot isostatic pressing.
Claim 9
Dependent Claim
19 words
A sintered ceramic cutting insert as claimed in claim 4, having fracture toughness greater than 5.5 MPa.m 1/2 .
References Cited (Backward Citations)
US4320203A
Cited
US4356272A
Cited
US4366254A
Cited
US4407970A
Cited
US4543343A
Cited
US4745091A
Cited
US4689077A
Cited
US4867761A
Cited
US4804645A
Cited
US4852999A
Cited
US5017524A
Cited
US5141901A
Cited
US5188908A
Cited
US5275981A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-07-04 | 1998-01-03 | 1998-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-04 | 2002-01-03 | 2002-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-04 | 2006-01-03 | 2006-07-05 | $7700.00 | Window Closed / Lapsed |