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Effect of thermal cycling on the microstructure of a directionally solidified Fe, Cr, Al-TaC eutectic alloyCylindrical bars (1.2 cm diameter) of Fe-13.6Cr-3.7Al-9TaC (wt %) eutectic alloy were directionally solidified in a modified Bridgman type furnace at 1 cm/h. The alloy microstructure consisted of aligned TaC fibers imbedded in a bcc Fe-Cr-Al matrix. Specimens of the alloy were thermally cycled from 1100 to 425 C in a burner rig. The effects of 1800 thermal cycles on the microstructure was examined by scanning electron microscopy, revealing a zig-zag shape of TaC fibers aligned parallel to the growth direction. The mechanism of carbide solution and reprecipitation on the (111) easy growth planes, suggested previously to account for the development of irregular serrations in Co-Cr-Ni matrix alloys, is believed to be responsible for these zig-zag surfaces.
Document ID
19770038187
Document Type
Reprint (Version printed in journal)
Authors
Harf, F. H. (NASA Lewis Research Center Cleveland, Ohio, United States)
Tewari, S. N. (NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
August 9, 2013
Publication Date
January 1, 1977
Publication Information
Publication: Metallurgical Transactions A - Physical Metallurgy and Materials Science
Volume: 8A
Subject Category
METALLIC MATERIALS
Distribution Limits
Public
Copyright
Other