US3801357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffusion coating
Assignee: Alloy Surfaces Co Inc
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Filing: 1972-01-20
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Granted: 1974-04-02
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Expires: 1992-01-20
Abstract
Abstract Diffusion coating of superalloys with aluminum is effectively prevented at desired locations by masking with nickel or cobalt aluminide having less than one atom of aluminum for each atom of nickel or cobalt, and packed against those locations. Chromium, silicon, iron or any combination of them can be coated along with the aluminum as by alloying with the aluminum used to provide the coating, and particularly effective particle size of such alloys is about 1 micron. Such sizes are produced by simultaneous magnesothermic reduction. Molybdenum and tungsten silicide particles can also be produced in this small size by such reduction and make effective diffusion coating materials. Diffusion coating can also be confined to restricted portions of work pieces without the above masking.
Inventors
- 👤 A Baldi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:55
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/28; C23C10/34; C23C10/36; C23C10/48; C23C10/50; C23C10/02; C23C10/04; C23C10/38; C23C10/40
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
89 words
In a process of diffusion coating with aluminum of a high temperature superalloy of nickel, cobalt or iron base, the step comprising preventing the aluminum coating from diffusing into undesired locations by covering said superalloy in selected areas with a masking composition which is a mixture of particles of an inert diluent and particles of an aluminide of nickel, the aluminide having between one-third and three-fourths atoms of aluminum for every atom of nickel, the diluent being from about one-fourth to about two-thirds of the masking composition by weight.
Claim 2
Dependent Claim
146 words
A process for diffusion coating selected portions of a high temperature cobalt or iron base superalloy with an aluminum-chromium mixture, wherein the improvement comprises the steps of providing a finely divided coating alloy of chromium with aluminum, placing said superalloy in a cementation pack with selected portions embedded in a mixture of said coating alloy and an inert diluent material to keep said mixture from sintering to the superalloy, the remaining portions of said superalloy being held in contact with a masking mixture comprising particles of an inert diluent and particles of an aluminide of cobalt or nickel, the aluminide having between one-third and three-fourths atoms of aluminum for every atom of cobalt or nickel, the diluent being from about one-fourth to about two-thirds of the masking mixture by weight, then heating the assembly to diffusion-coating temperature and activating the coating mixture with a halogen-containing vapor.
Claim 3
Dependent Claim
143 words
A process for diffusion coating selected portions of a high temperature nickel, cobalt or iron base superalloy with an aluminum-chromium mixture, wherein the improvement comprises the steps of providing a coating alloy of finely divided chromium with aluminum, placing said superalloy in a cementation pack with seleCted portions embedded in a mixture of said coating alloy and an inert diluent material to keep said mixture from sintering to the superalloy, the remaining portions of said superalloy being held in contact with a masking mixture comprising particles of an inert diluent and particles of an aluminide of nickel, the aluminide having between one-third and three-fourths atoms of aluminum for every atom of nickel, the diluent being from about one-fourth to about two-thirds of the masking mixture by weight, then heating the assembly to diffusion-coating temperature and activating the coating mixture with a halogen-containing vapor.
Claim 4
Dependent Claim
115 words
A diffusion coating process for diffusing aluminum into the surface of a high temperature nickel, cobalt or iron base superalloy embedded in a coating pack, wherein the improvement comprises embedding at least a portion of the workpiece in a masking composition to prevent aluminum coating from diffusing into the surface of the masked portion of the workpiece, said masking composition comprising a mixture of inert particles, chromium, and nickel aluminide particles having between one-third and three-fourths atoms of aluminum for every atom of nickel, the inert particles being from about one-fourth to about two-thirds of the mixture by weight, the chromium content being from about 1/4 to about 3 percent of the mixture by weight.
Claim 5
Dependent Claim
118 words
A diffusion coating process for diffusing aluminum into the surface of a high temperature cobalt or iron base superalloy embedded in a coating pack, wherein the improvement comprises embedding at least a portion of the workpiece in a masking composition to prevent aluminum coating from diffusing into the surface of the masked portion of the workpiece, said masking composition comprising a mixture of inert particles, chromium, and nickel or cobalt aluminide particles having between one-third and three-fourths atoms of aluminum for every atom of nickel or cobalt, the inert particles being from about one-fourth to about two-thirds of the mixture by weight, the chromium content being from about 1/4 to about 3 percent of the mixture by weight.
Claim 6
Dependent Claim
16 words
The combination of claim 1 in which the aluminum is diffusion coated along with another metal.
Claim 7
Dependent Claim
15 words
Th combination of claim 1 in which the aluminum is diffusion coated along with chromium.
Claim 8
Dependent Claim
15 words
The combination of claim 2 in which the aluminum is diffusion coated along with chromium.
Claim 9
Dependent Claim
16 words
The combination of claim 2 in which the aluminum is diffusion coated along with another metal.
Claim 10
Dependent Claim
11 words
The combination of claim 1 in which the diluent is alumina.
Claim 11
Dependent Claim
11 words
The combination of claim 2 in which the diluent is alumina.
Claim 12
Dependent Claim
92 words
In the process of diffusion coating a small portion of a metal work piece embedded in a diffusion coating pack containing the coating material and in an atmosphere containing a diffusion coating activator, the improvement according to which the diffusion coating pack is placed in contact only with the small portion of the work piece, and the remainder of the embedded workpiece surface is in contact with a pack that does not contain the coating material, and said coating pack is located within the pack that does not contain the coating material.
Claim 13
Dependent Claim
44 words
A mixture of chromium with an aluminide of nickel or cobalt, the aluminide having between one-third and three-fourths atom of aluminum for every atom of cobalt or nickel, and the chromium content of the mixture being between about 1/3 and 9 percent by weight.
Claim 14
Dependent Claim
24 words
The combination of claim 14 in which the aluminide is Ni3Al and the chromium content is between 3 and 3 1/2 percent by weight.
Claim 15
Dependent Claim
64 words
A particulate mixture of chromium with an aluminide of nickel or cobalt and an inert diffusion coating diluent, the aluminide having between one-third and three-fourths atom of aluminum for every atom of cobalt or nickel, and the chromium content of the mixture being between about 1/4 and 3 percent by weight, and the diluent content being between about 1/4 AND 2/3 percent by weight.
Claim 16
Dependent Claim
23 words
The combination of claim 16 in which the aluminide is Ni3Al and the chromium content is between 1.5 and 2.0 percent by weight.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |