Patent US3779719A successfully refreshed from Google Patents.
US3779719A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffusion coating of jet engine components and like structures
Assignee: Chromalloy American Corp
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Filing: 1970-12-03
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Granted: 1973-12-18
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Expires: 1990-12-03
Abstract
Abstract Greatly increased thermal fatigue cracking resistance of high temperature resistant base metals such as cobalt and nickel and their alloys used to fabricate jet engine components and like parts is realized by diffusion coating the base metal with chromium, silicon and aluminum in particular proportions to diffuse into the base metal to a uniform depth and distribution between and across intergranular boundaries in the base metal, enabling slowed initiation of thermal fatigue cracking in the diffusion coating as well as reduced corrosion in the base metal.
Inventors
- 👤 E Clark
- 👤 M Commanday
- 👤 W Martin
- 👤 P Plambeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:08
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/28; C23C10/34; C23C10/58; C23C10/52; C23C10/54; C23C10/56; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9335; Y10S428/941; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12736; Y10T428/1275; Y10T428/12771; Y10T428/12861; Y10T428/12931
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
27 words
Structure according to claim 1 in which intergranular spaces in the base metal beyond the uniform coating depth are free of aluminum introduced by the coating procedure.
Claim 2
Dependent Claim
12 words
Structure according to claim 1 in which said base metal in nickel.
Claim 3
Dependent Claim
12 words
Structure according to claim 1 in which said base metal is cobalt.
Claim 4
Dependent Claim
17 words
Structure according to claim 1 in which said base metal comprises nickel as the largest single ingredient.
Claim 5
Dependent Claim
17 words
Structure according to claim 1 in which said base metal comprises cobalt as the largest single ingredient.
Claim 6
Dependent Claim
19 words
Structure according to claim 1 in which said diffusion coating contains from 5 to 35 weight per cent silicon.
Claim 7
Dependent Claim
22 words
Structure according to claim 7 in which the crystalline arrangement of the diffusion coating layer is stable in air at 1, 750*F.
Claim 8
Dependent Claim
19 words
Structure according to claim 1 in which said diffusion coating contains from 10 to 30 weight per cent aluminum.
Claim 9
Independent Claim
142 words
The method of improving thermal fatigue cracking resistance in jet engine components or like structure comprising a high temperature resistant base metal selected from cobalt, nickel and alloys in which cobalt or nickel is the largest single ingredient which includes diffusing from 3 to 30 weight percent chromium and 10 to 30 weight percent aluminum into the structure surface at surface temperatures above about 1,750*C and for a time sufficient to form a diffusion coating from 0.5 mil to 20 mils in depth, and controlling the pattern of aluminum distribution through the diffusion coating to eliminate voids in the coating and intergranular incursions of aluminum into the base metal by incorporating silicon in the diffusion coating in an amount between 5 and 35 weight percent And in a ratio between 0.6 and 1.4 parts by weight of silicon per part of chromium.
Claim 10
Dependent Claim
18 words
Method according to claim 10 in which aluminum, chromium and silicon are sequentially diffused into the structure surface.
Claim 11
Dependent Claim
18 words
Method according to claim 10 in which aluminum, chromium and silicon are simultaneously diffused into the structure surface.
Claim 12
Dependent Claim
22 words
Method according to claim 10 in which the structure surface is heated to not higher than 1,900*F during diffusion of the coating.
Claim 13
Dependent Claim
42 words
Method according to claim 10 in which the structure is immersed into a diffusion pack composition containing 0.3 to 10 weight per cent aluminum, 3 to 40 weight per cent chromium and 5 to 35 weight per cent silicon for said diffusion.
Claim 14
Dependent Claim
18 words
Structure according to claim 1 in which said diffusion coating contains from 8 to 20 weight percent silicon.
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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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |