US3904789A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Masking method for use in aluminizing selected portions of metal substrates
Assignee: Chromalloy American Corp
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Filing: 1974-04-24
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Granted: 1975-09-09
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Expires: 1994-04-24
Abstract
Abstract Selected areas of steel parts are aluminized by masking the surface of a steel part except for the area to be aluminized by coating the surface of said part outside said selected portion with a masking metal. The part is then aluminized by embedding it in an aluminizing cementation pack and heated to an aluminizing temperature, following which the part is removed from the pack and the metal mask removed by dissolution in an aqueous solution selective to said metal.
Inventors
- 👤 Kenneth K Speirs
- 👤 William M Hoy
- 👤 Robert Bradley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:51
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/04; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
103 words
A METHOD FOR ALUMINIZING A SELECTED AREA OF A STEEL PART WHICH COMPRISES, MASKING THE SURFACE OF SAID PART EXCEPT FOR THE AREA TO BE ALUMINIZED BY ELECTROPLATING A METAL COATING OF A MASKING METAL SELECTED FROM THE GROUP CONSISTING OF COPPER, NICKEL AND CHROMIUM OF THICKNESS AT LEAST ABOUT 1 MIL TO SAID SURFACE, SUBJECTING SAID STEEL TO ALUMINIZING BY EMBEDDING SAID PART WITH THE MASKED SURFACE IN AN ALUMINIZING CEMENTATION PACK AND HEATING SAID PART AND PACK TO AN ALUMINIZING TEMPERATURE, REMOVING SAID PART FROM SAID PACK, SAID SELECTIVELY REMOVING THE MASKING METAL WHILE PRESERVING THE AREA WITH THE ALUMINIZED COATING.
Claim 2
Independent Claim
103 words
A METHOD FOR ALUMINIZING A SELECTED AREA OF A STEEL PART WHICH COMPRISES, MASKING THE SURFACE OF SAID PART EXCEPT FOR THE AREA TO BE ALUMINIZED BY ELECTROPLATING A METAL COATING OF A MASKING METAL SELECTED FROM THE GROUP CONSISTING OF COPPER, NICKEL AND CHROMIUM OF THICKNESS AT LEAST ABOUT 1 MIL TO SAID SURFACE, SUBJECTING SAID STEEL TO ALUMINIZING BY EMBEDDING SAID PART WITH THE MASKED SURFACE IN AN ALUMINIZING CEMENTATION PACK AND HEATING SAID PART AND PACK TO AN ALUMINIZING TEMPERATURE, REMOVING SAID PART FROM SAID PACK, SAID SELECTIVELY REMOVING THE MASKING METAL WHILE PRESERVING THE AREA WITH THE ALUMINIZED COATING.
Claim 3
Independent Claim
125 words
A METHOD FOR ALUMINIZING A SELECTED AREA OF A STEEL PART WHICH COMPRISES, MASKING THE SURFACE OF SAID PART EXCEPT FOR THE AREA TO BE ALUMINIZED BY ELECTROPOLATING A METAL COATING OF AT LEAST ABOUT 1 MIL THICK OF A MASKING METAL SELECTED FROM THE GROUP CONSISTING OF COPPER, NICKEL AND CHROMIUM TO SAID SURFACE, SUBJECTING SAID STEEL PART TO ALUMINIZING BY EMBEDDING SAID PART IN AN ALUMINIZING CEMENTATION PACK COMPRISING PARTICULATE ALUMINUM AND CONTAINING A SMALL BUT EFFECTIVE AMOUNT OF AN ENERGIZER OF ALUMINUM TRICHLORIDE AND HEATING SAID PART AND PACK TO AN ALUMINIZING TEMPERATURE, REMOVING SAID PART FROM SAID PACK, AND SELECTIVELY DISSOLVING THE MASKING METAL IN AN AQUEOUS ACID SOLUTION OF SUFFICIENT DISSOLUTION STRENGTH WHILE PRESERVING THE AREA WITH THE ALUMINIZED COATING.
Claim 4
Independent Claim
125 words
A METHOD FOR ALUMINIZING A SELECTED AREA OF A STEEL PART WHICH COMPRISES, MASKING THE SURFACE OF SAID PART EXCEPT FOR THE AREA TO BE ALUMINIZED BY ELECTROPOLATING A METAL COATING OF AT LEAST ABOUT 1 MIL THICK OF A MASKING METAL SELECTED FROM THE GROUP CONSISTING OF COPPER, NICKEL AND CHROMIUM TO SAID SURFACE, SUBJECTING SAID STEEL PART TO ALUMINIZING BY EMBEDDING SAID PART IN AN ALUMINIZING CEMENTATION PACK COMPRISING PARTICULATE ALUMINUM AND CONTAINING A SMALL BUT EFFECTIVE AMOUNT OF AN ENERGIZER OF ALUMINUM TRICHLORIDE AND HEATING SAID PART AND PACK TO AN ALUMINIZING TEMPERATURE, REMOVING SAID PART FROM SAID PACK, AND SELECTIVELY DISSOLVING THE MASKING METAL IN AN AQUEOUS ACID SOLUTION OF SUFFICIENT DISSOLUTION STRENGTH WHILE PRESERVING THE AREA WITH THE ALUMINIZED COATING.
Claim 5
Independent Claim
151 words
A METHOD OF ALUMIIZING A SELECTED AREA OF A CHROMIUNCONTAINING STEEL PART WHICH COMPRISES, APPLYING A COATING OF A RESIST MATERIAL TO SAID SELECTED AREA WHILE LEAVING THE REMAINING AREA EXPOSED, ELECTROPLATING A METAL COATING OF A MASKING METAL SELECTED FROM THE GROUP CONSISTING OF COPPER, NICKEL AND CHROMIUM OF THICKNESS OF AT LEAST ABOUT 1 MIL TO SAID EXPOSED AREA, REMOVING THE RESIST COATING FROM SAID STEEL PART AND CLEANING SAID PART, SUBJECTING SAID STEEL PART TO ALUMINIZING BY EMBEDDING SAID PART IN A CEMENTATION PACK COMPRISING PARTICULATE ALUMINUM POWDER AND CONTAINING A SMALL BUT EFFECTIVE AMOUNT RANGING UP TO ABOUT 5% BY WEIGHT OF SAID PACK OF ALUMINUM TRICHLORIDE AND HEATING SAID PACK TO AN ELEVATED ALUMINIZING TEMPERATURE, REMOVING SAID STEEL PART FROM SAID PACK, AND SELECTIVELY DISSOLVING THE MASKING METAL IN AN AQUEOUS NITRIC ACID SOLUTION OF SUFFICIENT DISSOLUTION STRENGTH WHILE PRESERVING THE AREA WITH THE ALUMINIZED COATING.
Claim 6
Independent Claim
151 words
A METHOD OF ALUMIIZING A SELECTED AREA OF A CHROMIUNCONTAINING STEEL PART WHICH COMPRISES, APPLYING A COATING OF A RESIST MATERIAL TO SAID SELECTED AREA WHILE LEAVING THE REMAINING AREA EXPOSED, ELECTROPLATING A METAL COATING OF A MASKING METAL SELECTED FROM THE GROUP CONSISTING OF COPPER, NICKEL AND CHROMIUM OF THICKNESS OF AT LEAST ABOUT 1 MIL TO SAID EXPOSED AREA, REMOVING THE RESIST COATING FROM SAID STEEL PART AND CLEANING SAID PART, SUBJECTING SAID STEEL PART TO ALUMINIZING BY EMBEDDING SAID PART IN A CEMENTATION PACK COMPRISING PARTICULATE ALUMINUM POWDER AND CONTAINING A SMALL BUT EFFECTIVE AMOUNT RANGING UP TO ABOUT 5% BY WEIGHT OF SAID PACK OF ALUMINUM TRICHLORIDE AND HEATING SAID PACK TO AN ELEVATED ALUMINIZING TEMPERATURE, REMOVING SAID STEEL PART FROM SAID PACK, AND SELECTIVELY DISSOLVING THE MASKING METAL IN AN AQUEOUS NITRIC ACID SOLUTION OF SUFFICIENT DISSOLUTION STRENGTH WHILE PRESERVING THE AREA WITH THE ALUMINIZED COATING.
Claim 7
Dependent Claim
18 words
The method of claim 3, wherein the resist material is wax, and wherein the masking metal is copper.
Claim 8
Dependent Claim
19 words
The method of claim 4, wherein the thickness of the copper coating ranges from about 2 to 7 mils.
Claim 9
Dependent Claim
39 words
The method of claim 5, wherein the area with the copper masking metal is selectively removed following aluminizing by dissolution with aqueous nitric acid solution of strength ranging from about 15% to 75% by volume of concentrated nitric acid.
Claim 10
Dependent Claim
26 words
The method of claim 6, wherein the strength of the aqueous nitric acid solution ranges from about 20% to 60% by volume of concentrated nitric acid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |