NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
A Simplified Test for Blanching Susceptibility of Copper AlloysGRCop-84 (Cu-8Cr-4Nb) is a dispersion-strengthened alloy developed for space-launch rocket engine applications, as a liner for the combustion chamber and nozzle ramp. Its main advantage over rival alloys, particularly NARloy-Z (Cu-Ag-Zr), the current liner alloy, is in high temperature mechanical properties. Further validation required that the two alloys be compared with respect to service performance and durability. This has been done, under conditions resembling those expected in reusable launch engine applications. GRCop-84 was found to have a superior resistance to static and cyclic oxidation up to approx. 700 C. In order to improve its performance above 700 C, Cu-Cr coatings have also been developed and evaluated. The major oxidative issue with Cu alloys is blanching, a mode of degradation induced by oxidation-reduction fluctuations in hydrogen-fueled engines. That fluctuation cannot be addressed with conventional static or cyclic oxidation testing. Hence, a further evaluation of the alloy substrates and Cu-Cr coating material necessitated our devising a test protocol that involves oxidaton-reduction cycles. This paper describes the test protocols used and the results obtained.
Document ID
20040034074
Acquisition Source
Glenn Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Thomas-Ogbuji, Linus U.
(QSS Group, Inc. Cleveland, OH, United States)
Humphrey, Donald
(QSS Group, Inc. Cleveland, OH, United States)
Setlock, John
(Case Western Reserve Univ. Cleveland, OH, United States)
Date Acquired
August 21, 2013
Publication Date
October 30, 2003
Subject Category
Metals And Metallic Materials
Meeting Information
Meeting: Materials Science and Technology 2003
Location: Chicago, IL
Country: United States
Start Date: November 1, 2003
Sponsors: Minerals, Metals and Materials Society
Funding Number(s)
CONTRACT_GRANT: NAS3-98008
OTHER: 22-708-31-20
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available