US4681818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxygen diffusion barrier coating
Assignee: National Aeronautics and Space Administration
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Filing: 1986-03-18
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Granted: 1987-07-21
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Expires: 2006-03-18
Abstract
Abstract A method is disclosed for coating a titanium panel or foil with aluminum and amorphous silicon to provide an oxygen barrier abrogating oxidation of the substrate metal. The process is accomplished with inexpensive procedures common in materials research laboratories, i.e., electron beam deposition and sputtering. The procedures are conducive to treating foil gage titanium and result in submicron layers which virtually add no weight to the titanium. The ultra-thin coatings diffusion bond with the substrate titanium without costly heating steps and the coatings blend with the substrate titanium until separate mechanical properties are subsumed by those of the substrate without cracking or spallation. This method appreciably increases the ability of titanium to mechanically perform in high thermal environments such as those witnessed on structures of space vehicles during re-entry.
Inventors
- 👤 Jalaiah Unnam
- 👤 Ronald K. Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:47
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/58; C23C14/5806; C23C14/06; C23C14/10; C23C14/14; C23C14/16; C23C14/5893; C23C26/00; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12431; Y10T428/12438; Y10T428/12493; Y10T428/12535; Y10T428/12611; Y10T428/12736; Y10T428/12743; Y10T428/12771; Y10T428/12806
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
86 words
A method of providing an oxygen barrier coating onto a titanium substrate comprising the steps of: providing a titanium substrate surface, electron-beam-evaporative depositing a submicron aluminum layer onto the titanium substrate surface, depositing by sputtering a submicron silicon-dioxide layer onto the submicron aluminum layer, and exposing the titanium substrate to an elevated temperature during service to chemically react the titanium substrate with the submicron aluminum layer and the submicron silicon-dioxide layer to form a thermal protective barrier of aluminide and silicide on the titanium substrate surface.
Claim 2
Independent Claim
86 words
A method of providing an oxygen barrier coating onto a titanium substrate comprising the steps of: providing a titanium substrate surface, electron-beam-evaporative depositing a submicron aluminum layer onto the titanium substrate surface, depositing by sputtering a submicron silicon-dioxide layer onto the submicron aluminum layer, and exposing the titanium substrate to an elevated temperature during service to chemically react the titanium substrate with the submicron aluminum layer and the submicron silicon-dioxide layer to form a thermal protective barrier of aluminide and silicide on the titanium substrate surface.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein the titanium substrate is a titanium alloy.
Claim 4
Dependent Claim
13 words
The method of claim 2 wherein the titanium alloy is foil gauge Ti-6Al-2Sn-4Zr-2Mo.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein the titanium substrate is commercial purity titanium.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein the titanium substrate is of foil gage thickness.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein the depositing of the submicron silicon-dioxide layer is by sputtering the submicron aluminum layer in an argon environment.
Claim 8
Dependent Claim
30 words
The method of claim 1 wherein the exposure of the coated titanium substrate is to an elevated temperature of approximately 980° K. and for a period of approximately twenty-four hours.
Claim 9
Dependent Claim
21 words
A foil gage titanium substrate having an improved thermal protective oxygen barrier coating thereon prepared by the method of claim 1.
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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) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |