US4591482A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure assisted sinter process
Assignee: Thermal Technology Inc
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Filing: 1985-08-29
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Granted: 1986-05-27
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Expires: 2005-08-29
Abstract
Abstract Pressure assisted sintering achieves full densification in short sinter times with low grain growth. This result is enabled by a stage of sintering to a condition of closed porosity (14) followed by a pressure assisted sinter (PAS) stage (16) carried out at a temperature close to, but just below, sinter temperature. Advantageously a small melt formation is induced by a brief temperature spiking (18) during the PAS stage to enable collapse of voids.
Inventors
- 👤 Andrew C. Nyce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:42
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/0555; H01F1/0557; B; B22; B22F; B22F3/00; B22F3/12; B22F3/14
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
74 words
Method of formation of metal parts comprising the steps of: (a) forming an alloy metal powder compact; (b) heating the compact to a condition of sinter bonding; and (c) extending the sintering of the compact to achieve a density over 98% theoretical density at a temperature within minus 5-10% to plus 3-5% of the temperature of (b) under an applied pressure in the range 1,000 to 3,000 psi over a period of 5-20 minutes.
Claim 2
Dependent Claim
74 words
Method of formation of metal parts comprising the steps of: (a) forming an alloy metal powder compact; (b) heating the compact to a condition of sinter bonding; and (c) extending the sintering of the compact to achieve a density over 98% theoretical density at a temperature within minus 5-10% to plus 3-5% of the temperature of (b) under an applied pressure in the range 1,000 to 3,000 psi over a period of 5-20 minutes.
Claim 3
Dependent Claim
22 words
Method in accordance with claim 1 wherein the step (c) incorporates a temperature spiking increase of 50° C.-200° C. of 1-5 minutes.
Claim 4
Dependent Claim
18 words
Method in accordance with claim 1 wherein the steps (b) and (c) comprise essentially a continuous heating process.
Claim 5
Dependent Claim
17 words
Method in accordance with claim 1 wherein the metal powder so treated is an alloy of titanium-aluminum-vanadium.
Claim 6
Dependent Claim
17 words
Method in accordance with claim 1 wherein the metal powder so treated is a low carbon steel.
Claim 7
Dependent Claim
16 words
Method in accordance with claim 1 wherein the metal powder so treated is a nickel alloy.
Claim 8
Dependent Claim
15 words
Method in accordance with claim 1 wherein the metal powder so treated is stainless steel.
Claim 9
Dependent Claim
16 words
Method in accordance with claim 1 wherein the metal powder so treated is a cobalt-samarium alloy.
Claim 10
Dependent Claim
16 words
Method in accordance with claim 1 wherein the metal powder so treated is a samarium-neodynium alloy.
Claim 11
Dependent Claim
15 words
Method in accordance with claim 1 wherein the metal powder so treated is a superalloy.
Claim 12
Dependent Claim
18 words
Method in accordance with claim 1 wherein the metal powder so treated is a rare earth base alloy.
Claim 13
Dependent Claim
17 words
Method in accordance with claim 1 wherein the metal powder so treated is an aluminum base alloy.
Claim 14
Dependent Claim
17 words
Method in accordance with claim 1 wherein the metal powder so treated is a copper base alloy.
Claim 15
Dependent Claim
15 words
A metal alloy part of complex form as produced by the process of claim 1.
Claim 16
Dependent Claim
17 words
The product of claim 14 as a refractory metal alloy in the form of a turbine blade.
Claim 17
Dependent Claim
17 words
The product of claim 14 as a refractory metal alloy in the form of an aircraft airfoil.
References Cited (Backward Citations)
US4331477A
Cited
US4478790A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-26 | 1989-11-25 | 1990-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-26 | 1993-11-25 | 1994-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-26 | 1997-11-25 | 1998-05-27 | $7700.00 | Window Closed / Lapsed |