Directional solidification of Cu- Pb and Bi- Ga monotectic alloys under normal gravity and during parabolic flight
Directional solidification of Cu- Pb and Bi- Ga monotectic alloys under normal gravity and during parabolic flight
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DOI：
10.1007/bf02645818
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发表时间：
1988-11
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影响因子：
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通讯作者：
B. Dhindaw;D. Stefanescu;Ashutosh Kumar Singh;P. Curreri
中科院分区：
文献类型：
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作者：
B. Dhindaw;D. Stefanescu;Ashutosh Kumar Singh;P. Curreri
标称超偏晶成分的 Cu-Pb 和 Bi-Ga 偏晶合金在不同的熔炉平移速率、温度梯度和重力水平下定向凝固。通过在地面条件下和在 NASA KC-135 飞机上的熔炉中凝固合金来改变重力，飞机沿抛物线轨迹飞行。 L2相的高平移速率、高梯度、高重力水平以及较高的密度和较低的导热率有利于纤维复合结构的形成，而相反的条件则导致由α基体中的L2液滴组成的结构。提出了一种最初由 Ulhmannet 等人阐述的修正粒子吞噬理论来解释这些观察结果。
Cu-Pb and Bi-Ga monotectic alloys of nominal hypermonotectic compositions were directionally solidified under various furnace translation rates, temperature gradients, and gravity levels. Gravity was varied by solidifying the alloys under ground conditions and in the furnace aboard NASA KC-135 aircraft, flying on parabolic trajectories. High translation rates, high gradients, high gravity levels, and higher density and lower thermal conductivity of the L2phase favored the formation of fiber composite structure, while the opposite conditions resulted in structures consisting of L2droplets in α matrix. A modified particle engulfment theory as originally enunciated by Ulhmannet al.is proposed to explain these observations.