Analytical, numerical, and experimental analysis of inverse macrosegregation during upward unidirectional solidification of Al-Cu alloys

被引:50
作者
Ferreira, IL [1 ]
Santos, CA
Voller, VR
Garcia, A
机构
[1] Univ Estadual Campinas, UNICAMP, Dept Mat Engn, BR-13083970 Campinas, SP, Brazil
[2] Univ Minnesota, Dept Civil Engn, Minneapolis, MN 55455 USA
来源
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE | 2004年 / 35卷 / 02期
基金
巴西圣保罗研究基金会;
关键词
D O I
10.1007/s11663-004-0030-8
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The present work focuses on the influence of alloy solute content, melt superheat, and metal/mold heat transfer on inverse segregation during upward solidification of Al-Cu alloys. The experimental segregation profiles of Al 4.5 wt pet Cu, 6.2 wt pet Cu, and 8.1 wt pet Cu alloys are compared with theoretical predictions furnished by analytical and numerical models, with transient h(i) profiles being determined in each experiment. The analytical model is based on an analytical heat-transfer model coupled with the classical local solute redistribution equation proposed by Flemings and Nereo. The numerical model is that proposed by Voller, with some changes introduced to take into account different thermophysical properties for the liquid and solid phases, time variable metal/mold interface heat-transfer coefficient, and a variable space grid to assure the accuracy of results without raising the number of nodes. It was observed that the numerical predictions generally conform with the experimental segregation measurements and that the predicted analytical segregation, despite its simplicity, also compares favorably with the experimental scatter except for high melt superheat.
引用
收藏
页码:285 / 297
页数:13
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