US4978558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for applying diffusion coating masks
Assignee: RTX Corp
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Filing: 1988-06-10
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Granted: 1990-12-18
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Expires: 2008-06-10
Abstract
Abstract Methods for selectively applying a diffusion aluminide coating to the surface of a metal article while keeping other article surfaces free of the coating are described. The method includes the steps of injection molding a mixture of materials onto the surfaces which are to be kept free of coating; the material comprises solid particles effective in preventing deposition of the coating onto the surfaces and a moldable amorphous thermoplastic resin; it contains no volatilizable solvents. The mixture is applied to the article surface to a thickness of about 5 millimeters. It is useful in pack diffusion as well as vapor phase diffusion aluminide coating operations.
Inventors
- 👤 Foster P. Lamm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:15
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
72 words
A method for applying a metal coating onto the surface of a metal substrate comprising the step of injection molding a masking mixture onto a portion of said surface, wherein the masking mixture is characterized by no volatilizable solvents and comprises solid particles effective in preventing deposition of the coating onto the substrate surface an a moldable amorphous thermoplastic resin, and then diffusing the coating onto the unmasked portion of the substrate.
Claim 2
Independent Claim
72 words
A method for applying a metal coating onto the surface of a metal substrate comprising the step of injection molding a masking mixture onto a portion of said surface, wherein the masking mixture is characterized by no volatilizable solvents and comprises solid particles effective in preventing deposition of the coating onto the substrate surface an a moldable amorphous thermoplastic resin, and then diffusing the coating onto the unmasked portion of the substrate.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein said masking mixture consists essentially of, by weight, about 80-87% solid particles and about 13-20% resin.
Claim 4
Dependent Claim
34 words
The method of claim 2, wherein the solid particles are, by weight, about 50-70% nickel and 30-50% aluminum oxide, and wherein the resin consists essentially of, by weight, about 12-14% polystyrene and 1-3% polypropylene.
Claim 5
Dependent Claim
29 words
The method of claim 3, wherein the solid particles are about 60% nickel and 40% aluminum oxide, and the resin consists essentially of about 13% polystyrene and 2% polypropylene.
Claim 6
Independent Claim
128 words
A method for applying a diffusion aluminide coating onto the surface of a gas turbine engine blade while at the same time preventing the application of said coating onto other surfaces of the blade, comprising the step of applying a masking mixture onto said other surfaces by injecting molding a mixture characterized by no volatilizable solvents and which comprises solid particles effective in preventing deposition of the coating on said other surfaces and a moldable amorphous thermoplastic resin, and then cooling the masking mixture at a rate equal to or greater than air cool; diffusing aluminum into said unmasked blade surfaces by pack diffusion or gas phase diffusion; removing the blade from said source of aluminum and cooling; and then removing the mask from the masked blade surfaces.
Claim 7
Independent Claim
128 words
A method for applying a diffusion aluminide coating onto the surface of a gas turbine engine blade while at the same time preventing the application of said coating onto other surfaces of the blade, comprising the step of applying a masking mixture onto said other surfaces by injecting molding a mixture characterized by no volatilizable solvents and which comprises solid particles effective in preventing deposition of the coating on said other surfaces and a moldable amorphous thermoplastic resin, and then cooling the masking mixture at a rate equal to or greater than air cool; diffusing aluminum into said unmasked blade surfaces by pack diffusion or gas phase diffusion; removing the blade from said source of aluminum and cooling; and then removing the mask from the masked blade surfaces.
Claim 8
Dependent Claim
41 words
The method of claim 5, wherein the solid particles in the masking mixture are, by weight, about 50-70% nickel and 30-50% aluminum oxide, and wherein the resin in the mixture consists essentially of, by weight, about 12-14% polystyrene and 1-3% polypropylene.
Claim 9
Dependent Claim
38 words
The method of claim 6, wherein the solid particles in the masking mixture are about 60% nickel and about 40% aluminum oxide, and the resin in the mixture consists essentially of about 13% polystyrene and about 2% polypropylene.
References Cited (Backward Citations)
US3202543A
Cited
US3801357A
Cited
US4617202A
Cited
US3764371A
Cited
US3785854A
Cited
US3904789A
Cited
US4128522A
Cited
US4181758A
Cited
JPS55154139A
Cited
US4845139A
Cited
US4467016A
Cited
JPS57178732A
Cited
US4725650A
Cited
US4568244A
Cited
US4591400A
Cited
US4737540A
Cited
US4728573A
Cited
US4687796A
Cited
US4695509A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-17 | 1994-06-18 | 1994-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-17 | 1998-06-18 | 1998-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-17 | 2002-06-18 | 2002-12-18 | $7700.00 | Window Closed / Lapsed |