NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Effect of thermosolutal convection on the solid-liquid interface in Pb-Au alloyLiquid-solid interface distortion in the region of primary dendrite tips has been investigated in directionally solidified Pb-8 wt pct Au alloy. The distortions are caused by thermosolutal convection despite choice of growth conditions which should have been thermally and solutally stabilizing. The convection produces clustering of primary dendrites on a plane perpendicular to the growth direction. It produces a mushy zone, where the primary dendrites do not protrude with a uniform length, across the specimen cross section, resulting in large macrosegregation in the transverse direction. However, little macrosegregation is observed along the growth direction. The mushy zone, with uneven dendrite lengths, forms in the beginning of directional solidification. Its shape and dendrite distribution do not show much change during subsequent solidification. Tip morphologies of primary dendrites, within the dendrite clusters, appear to follow the morphological stability relationship.
Document ID
19900064608
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Tewari, S. N.
(Cleveland State University OH, United States)
Chopra, M. A.
(IBM Corp. Austin, TX, United States)
Date Acquired
August 14, 2013
Publication Date
September 1, 1990
Publication Information
Publication: Microgravity Science and Technology
Volume: 3
ISSN: 0938-0108
Subject Category
Metallic Materials
Accession Number
90A51663
Funding Number(s)
CONTRACT_GRANT: NCC2-395
Distribution Limits
Public
Copyright
Other

Available Downloads

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