US3862840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for manufacture of hard and non-deformable alloys without compacting by sintering in the solid-liquid phase
Assignee: Airco Inc
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Filing: 1972-12-20
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Granted: 1975-01-28
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Expires: 1992-12-20
Abstract
Abstract Hardfacing alloy powders are poured into a resuable mold. Thereafter, without application shapes external compaction forces, the mold and contained powders are subjected to a heating schedule which brings about direct particle liquid phase sintering of the contained powders to give high density products. The shape thus operated upon have one dimension less than or equal to about one-half inch, with at least one of the other dimensions being much larger than the specified dimension.
Inventors
- 👤 Harbhajan S Nayar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:03
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/10; C; C22; C22C; C22C1/00; C22C1/04; C22C1/0433
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
40 words
A method in accordance with claim 1, wherein said powder comprises a nickel-based alloy having constituents in the following weight percent ranges; C-0.4 to 1.0; B-2.5 to 4.5; Si-2.0 to 5.5; Fe-1.0 to 5.0; Cr-10 to 18; and balance, nickel.
Claim 2
Dependent Claim
25 words
A process in accordance with claim 1, wherein said fill density of said powder in said mold is at least 40% of its theoretical density.
Claim 3
Dependent Claim
14 words
A process in accordance with claim 3, wherein said composition comprises a pre-alloyed powder.
Claim 4
Dependent Claim
14 words
A process in accordance with claim 3, wherein said composition comprises a blended powder.
Claim 5
Dependent Claim
12 words
A method in accordance with claim 3, wherein said mold comprises graphite.
Claim 6
Dependent Claim
12 words
A method in accordance with claim 3, wherein said mold comprises zirconia.
Claim 7
Dependent Claim
12 words
A method in accordance with claim 3, wherein said mold comprises AlTiBN.
Claim 8
Dependent Claim
52 words
A method in accordance with claim 3, wherein said heat step C is effected by subjecting said mold and contents to a heating schedule comprising in successive steps a slowly rising temperature for pre-heating; a flat temperature plateau at or above the said sintering temperature; and a slowly falling temperature for cooling.
Claim 9
Dependent Claim
28 words
A method in accordance with claim 9, wherein said heat treatment schedule is effected by passing said mold and contents through successively spaced zones of a heating furnace.
Claim 10
Dependent Claim
38 words
A method according to claim 9 wherein the duration of heating at said plateau step and the temperature thereat are such as to increase the density of the forms being sintered to at least 80% of theoretical density.
References Cited (Backward Citations)
US2828226A
Cited
US2833638A
Cited
US3329487A
Cited
US3372024A
Cited
US3502466A
Cited
US3689257A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |