NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Metallographic examination of TD-nickel base alloysTechniques are evaluated for chemical, electrochemical, and thermal etching of thoria dispersed (TD) nickel alloys. An electrochemical etch is described which yielded good results only for large grain sizes of TD-nickel. Two types of thermal etches are assessed for TD-nickel: an oxidation etch and vacuum annealing of a polished specimen to produce an etch. It is shown that the first etch was somewhat dependent on sample orientation with respect to the processing direction, the second technique was not sensitive to specimen orientation or grain size, and neither method appear to alter the innate grain structure when the materials were fully annealed prior to etching. An electrochemical etch is described which was used to observe the microstructures in TD-NiCr, and a thermal-oxidation etch is shown to produce better detail of grain boundaries and to have excellent etching behavior over the entire range of grain sizes of the sample.
Document ID
19750051416
Document Type
Reprint (Version printed in journal)
Authors
Kane, R. D. (Exxon Production Research Co. Houston, Tex., United States)
Petrovic, J. J. (USAF, Aerospace Research Laboratories, Wright-Patterson AFB Ohio, United States)
Ebert, L. J. (Case-Western-Reserve University Cleveland, Ohio, United States)
Date Acquired
August 8, 2013
Publication Date
June 1, 1975
Publication Information
Publication: Metallurgical Transactions A - Physical Metallurgy and Materials Science
Volume: 6A
Subject Category
METALLIC MATERIALS
Funding Number(s)
CONTRACT_GRANT: NGL-36-003-094
Distribution Limits
Public
Copyright
Other