Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
Pb-2.2 and 5.8 wt pet Sb alloys were directionally solidified with a positive thermal gradient of 140 K cm(-1) at growth speeds ranging from 0.8 to 30 mu m s(-1), and then quenched to retain the mushy-zone morphology. Chemical analysis along the length of the directionally solidified portion and in the quenched melt ahead of the dendritic array showed extensive longitudinal macrosegregation, Cellular morphologies growing at smaller growth speeds are associated with larger amounts of macrosegregation as compared with the dendrites growing at higher growth speeds. Convection is caused, mainly, by the density inversion in the overlying melt ahead of the cellular/dendritic array because of the antimony enrichment at the array tip. Mixing of the interdendritic and bulk melt during directional solidification is responsible for the observed longitudinal macrosegregation.
Ojha, S. N.; Ding, G. L.; Lu, Y.; Reye, J.; and Tewari, Surendra N., "Macrosegregation Caused by Thermosolutal Convection During Directional Solidification of Pb-Sb Alloys" (1999). Chemical & Biomedical Engineering Faculty Publications. 23.
Ojha, S.N., Ding, G., Lu, Y., Reye, J., & Tewari, S.N. (1999). Macrosegregation Caused by Thermosolutal Convection During Directional Solidification of Pb-Sb Alloys. Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science 30, 2167-2171.
Copyright 1999 ASM International. This paper was published in Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, Vol. 30, Issue 8, pp. 2167-2171 and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.
Available on publisher's site at: http://hts.asminternational.org/portal/site/smst/AsmStore/ProductDetails/?vgnextoid=1ce9b2eaf71e5210VgnVCM100000621e010aRCRD.