Document Type

Article

Publication Date

8-1999

Publication Title

Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

Abstract

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.

Original Citation

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.

Volume

30

Issue

8

DOI

10.1007/s11661-999-0028-6

Version

Publisher's PDF

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