US5238481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat resistant sintered hard alloy
Assignee: Toyo Kohan Co Ltd
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Filing: 1992-01-23
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Granted: 1993-08-24
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Expires: 2012-01-23
Abstract
Abstract A heat-resistant sintered hard alloy comprises 35% to 95% by weight of a WCoB type complex boride in a cobalt base alloy. The alloy contains 1.5% to 4.1% boron, 19.1% to 69.7% tungsten, optionally to 25% chromium, the balance being cobalt and a maximum of 1% impurities. Nickel, iron and/or copper may be substituted for portions of the cobalt content.
Inventors
- 👤 Kenichi Takagi
- 👤 Masao Komai
- 👤 Yoshihiko Isobe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:26
CPC Classifications
C; C22; C22C; C22C29/00; C22C29/14; C22C32/00; C22C32/0047; C22C32/0073
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
70 words
A heat-resistant sintered hard alloy containing 35 to 95% by weight of a WCoB type complex boride containing chromium in a cobalt base alloy matrix phase, wherein said hard alloy consists of 1.5 to 4.1% by weight of boron, 19.1 to 69.7% by weight of tungsten, 1 to 25% by weight of chromium, the balance being cobalt, and a maximum of 1%, by weight of the alloy, of unavoidable impurities.
Claim 2
Dependent Claim
70 words
A heat-resistant sintered hard alloy containing 35 to 95% by weight of a WCoB type complex boride containing chromium in a cobalt base alloy matrix phase, wherein said hard alloy consists of 1.5 to 4.1% by weight of boron, 19.1 to 69.7% by weight of tungsten, 1 to 25% by weight of chromium, the balance being cobalt, and a maximum of 1%, by weight of the alloy, of unavoidable impurities.
Claim 3
Dependent Claim
76 words
A heat-resistant sintered hard alloy according to claim 1, which further comprises at least one of nickel, iron and copper, wherein nickel, when present, substitutes for cobalt in the range of 0.2 to 30% by weight of cobalt content, iron, when present, substitutes for cobalt in the range of 0.2 to 15% by weight of cobalt content, and copper, when present, substitutes for cobalt in the range of 0.1 to 7.5% by weight of cobalt content.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-23 | 1997-02-22 | 1997-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-23 | 2001-02-22 | 2001-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-23 | 2005-02-22 | 2005-08-24 | $7700.00 | Window Closed / Lapsed |