Superior oxidation protection for nickel-base alloys at temperatures up to 1367 K was obtained with cobalt-base alloy coating. Coating had 25 Cr, 14 Al, and 0.5 Y weight percent composition. Coating was applied by electron beam vapor deposition to thickness of 76 to 127 microns

Elam, R. C.

Talboom, F. P.

Wilson, L. W.

English

NASA Technical Reports Server

December 1972	 B7210150 
• 
NASA TECH BRIEF 
Lewis Research Center 	 A 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Advanced Protective Coating for Superalloys 
.
A new coating has been developed which results in a 
superior oxidation protection for nickel-base alloys at 
temperatures up to 1367 K (2000°F). The coating is a 
cobalt-base alloy containing the following weight percent 
composition: 25 chromium, 14 aluminum and 0.5 
yttrium. The unique features of this coating result in 
part from the coating application process (overlay coat-
ing) in that the deposition of the protective surface 
alloy layer does not depend on aluminum reaction with 
the superalloy substrate to form aluminides, as is the 
case for the more conventional coatings. This new coat-
ing was specifically developed to protect the high 
strength nickel alloy NASA TRW-VIA (described in 
NASA Tech Brief 68-10344). The coating was applied in 
a vacuum by electron beam physical vapor deposition 
to a thickness range of 76 to 127 pm (0.003 to 0.005 
inch). After passing ballistic impact tests and oxidation 
tests in a static air furnace for 200 hours at 1367 K 
(20000F), the coating resisted burner rig oxidation 
testing in the combustion products of iF-S fuel and air 
at 1367 K (2000°F) for 1100 hours without failure. This 
life is three times as much as that displayed by speci-
mens coated with an aluminide now in engine service. 
Limited mechanical test results indicate that the coating 
does not adversely affect the tensile and stress rupture 
properties of the substrate nickel-base superalloy.
Notes: 
1. The following documentation may be obtained from: 
National Technical Information Service 
Springfield, Virginia 22151 
Single document price $3.00 
(or microfiche $0.95) 
Reference: NASA CR-72813 (N70-17669) 
Evaluation of Advanced Superalloy Protection 
Systems 
2. Technical questions may be directed to: 
Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio 44135 
Reference: B72-10150 
Patent status: 
No patent action is contemplated by NASA 
Source: F. P. Talboom, R. C. Elam and L. W. Wilson of 
Pratt and Whitney
under contract to
Lewis Research Center 
(LEW-1147 3) 
•
Category 04 
This document was prepared under the sponsorship of the National 	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States 	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States 	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19720000150 2020-03-17T03:32:06+00:00Z


Advanced protective coating for superalloys

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