US4514469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Peened overlay coatings
Assignee: RTX Corp
•
Filing: 1981-09-10
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Granted: 1985-04-30
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Expires: 2001-09-10
Abstract
Abstract Disclosed are coatings which are improved by a special peening process. Uniform sized spherical steel shot, in the range 1-2.5 mm is impacted at uniform low velocities onto a coated workpiece. Peening intensities are in the range 0.30-0.60 mm N. MCrAlY high temperature coatings are particularly improved, with densities of the order of 99 percent. Physical vapor desposited coatings have surface finishes of the order of 30×10 -6 inch AA (Arithmetic Average) and plasma sprayed coatings have finishes of the order of 100×10 -6 inch AA compared to unpeened finishes of 50-60×10 -6 inch AA and 200-300×10 -6 AA respectively.
Inventors
- 👤 Joseph F. Loersch
- 👤 James W. Neal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:27
CPC Classifications
C; C22; C22F; C22F1/00; C21; C21D; C21D7/00; C21D7/02; C21D7/04; C21D7/06; C23; C23C; C23C14/00; C23C14/58; C23C14/5886; C23C4/00; C23C4/12; C23C4/134; C23C4/18; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12063
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
63 words
An article having an overlay coating with a surface finish smoother than about 50×10 -6 inch Arithmetic Average produced by a process which comprises first applying a coating to a workpiece, and then peening the coating surface with spherical shot having a diameter uniform to ±4% and a velocity uniform to ±4%, the diameter of the shot lying in the range 1-2.5 mm.
Claim 2
Dependent Claim
63 words
An article having an overlay coating with a surface finish smoother than about 50×10 -6 inch Arithmetic Average produced by a process which comprises first applying a coating to a workpiece, and then peening the coating surface with spherical shot having a diameter uniform to ±4% and a velocity uniform to ±4%, the diameter of the shot lying in the range 1-2.5 mm.
Claim 3
Dependent Claim
23 words
The article of claim 1, wherein the coating is heat treated after peening to cause consolidation and sealing of deflects in the coating.
Claim 4
Dependent Claim
41 words
The article of claim 1 wherein the article is made of superalloy and has a high temperature oxidation and corrosion resisting coating of MCrAlY, where M is a metal selected from the group consisting of Fe, Co, Ni, and mixtures thereof.
Claim 5
Dependent Claim
42 words
The article of claim 3 wherein the coating is MCrAlY deposited by physical vapor deposition, and after shot peening has a surface finish smoother than about 40×10 -6 inch Arithmetic Average, and a density of at least about 99 percent of theoretical.
Claim 6
Dependent Claim
18 words
The article of claim 4 wherein the coating is heat treated after peening at 1040° C. or greater.
Claim 7
Dependent Claim
63 words
An article having an overlay plasma coating with a surface finish smoother than about 100×10 -6 inch Arithmetic Average produced by a process which comprises first spraying a plasma coating on the workpiece, and then peening the coating surface with spherical shot having diameter uniform to ±4% and velocity uniform to ±4%, the diameter of the shot lying in the range 1.5-2 mm.
Claim 8
Dependent Claim
63 words
An article having an overlay plasma coating with a surface finish smoother than about 100×10 -6 inch Arithmetic Average produced by a process which comprises first spraying a plasma coating on the workpiece, and then peening the coating surface with spherical shot having diameter uniform to ±4% and velocity uniform to ±4%, the diameter of the shot lying in the range 1.5-2 mm.
Claim 9
Dependent Claim
17 words
The article of claim 1 or 6 wherein the shot diameter is in the range 1.5-2 mm.
Claim 10
Dependent Claim
20 words
The article of claim 1 or 6 wherein the peening intensity is in the range of about 0.3-0.6 mm N.
Claim 11
Dependent Claim
23 words
The article of claim 6 wherein the coating is heat treated after peening to cause consolidation and sealing of defects in the coating.
Claim 12
Dependent Claim
27 words
The article of claim 6 wherein the coating is comprised of MCrAlY and after shot peening has a density of at least about 98 percent of theoretical.
Claim 13
Dependent Claim
87 words
In the method of applying an overlay coating to an article wherein the coating is shot peened and heat treated, the improvement which comprises peening the coating before heat treatment with shot which has a diameter uniform to ±4% in the range 1-2.5 mm, a velocity substantially uniform to ±4%, and an energy level substantially uniform to ±25% to provide an intensity of 0.3-0.6 mm N and to thereby densify the coating and to provide it with a finish of less than 100×10 -6 inch Arithmetic Average.
Claim 14
Dependent Claim
87 words
In the method of applying an overlay coating to an article wherein the coating is shot peened and heat treated, the improvement which comprises peening the coating before heat treatment with shot which has a diameter uniform to ±4% in the range 1-2.5 mm, a velocity substantially uniform to ±4%, and an energy level substantially uniform to ±25% to provide an intensity of 0.3-0.6 mm N and to thereby densify the coating and to provide it with a finish of less than 100×10 -6 inch Arithmetic Average.
Claim 15
Dependent Claim
22 words
The method of claim 11 wherein the coating is of the MCrAlY type and the heat treatment is at about 1040° C.
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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) | 1988-04-29 | 1988-10-29 | 1989-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-29 | 1992-10-29 | 1993-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-29 | 1996-10-29 | 1997-04-30 | $7700.00 | Window Closed / Lapsed |