NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
The transition from columnar to equiaxed dendritic growth in proeutectic, low-volume fraction copper, Pb-Cu alloysLead, 17.1, 11.2, and 5 volume fraction copper (14, 9, and 4 wt pct Cu) alloys have been directionally solidified at constant growth velocities ranging from 1 to 100 microns/s. Serially increasing the growth velocity within this range results in a graded microstructural transition from fully columnar, albeit segregated, copper dendrites in a lead matrix to one consisting only of equiaxed grains. The imposed velocity necessary to effect fully equiaxed growth is found to drop rapidly as the volume fraction of copper is decreased. Factors which complicate the controlled, directional solidification of these alloys are discussed and the experimental results are interpreted in view of, and seen to be in qualitative agreement with, Hunt's theory on the transition from columnar to equiaxed growth of dendrites.
Document ID
19920059049
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Kim, Shinwoo
(NASA Headquarters Washington, DC United States)
Grugel, R. N.
(Vanderbilt University Nashville, TN, United States)
Date Acquired
August 15, 2013
Publication Date
June 1, 1992
Publication Information
Publication: Metallurgical Transactions A - Physical Metallurgy and Materials Science
Volume: 23A
Issue: 6, Ju
ISSN: 0360-2133
Subject Category
Metallic Materials
Accession Number
92A41673
Distribution Limits
Public
Copyright
Other

Available Downloads

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