Thermosolutal convection during cellular arrayed growth of Pb-Sn alloysThermosolutal convection caused by the solute build up ahead of the growing arrays of cells and dendrites results in macrosegregation along the length of the Pb-Sn alloy (10 to 58 wt pct Sn) specimens when they are directionally solidified in a positive thermal gradient (melt on top, solid below, and gravity pointing down). At a constant thermal gradient, the extent of macrosegregation increases with decreasing growth speed as the microstructure changes from dendritic, to cellular and to planar. An empirical parameter, effective partition coefficient, obtained from the dependence of the longitudinal macrosegregation on fraction distance solidified can be used to represent the extent of macrosegregation.
Document ID
19930038671
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Tewari, S. N. (NASA Lewis Research Center Cleveland, OH, United States)
Shah, Rajesh (Cleveland State Univ. OH, United States)
Chopra, M. A. (NASA Lewis Research Center Cleveland, OH; IBM Corp., Austin, TX, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1993
Subject Category
Materials Processing
Report/Patent Number
AIAA PAPER 93-0262
Meeting Information
Meeting: AIAA, Aerospace Sciences Meeting and Exhibit