ON THE FORMATION OF THE STIRCAST STRUCTURE
ON THE FORMATION OF THE STIRCAST STRUCTURE
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DOI：
10.1007/bf01145499
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发表时间：
1986-02-01
影响因子：
4.5
通讯作者：
SMEULDERS, RJ
中科院分区：
文献类型：
--
作者：
MOLENAAR, JMM;KATGERMAN, L;SMEULDERS, RJ
为了解释搅拌铸造合金的非枝晶组织，研究了搅拌大块液体中的凝固条件。提出了一种搅拌凝固模型，可以比较金属合金和有机类似物的凝固行为。这表明，在普朗特数大于1的情况下，搅拌促进了固体在大体积液体中的形核和长大。结果还表明，流体流动降低了散体液体中悬浮颗粒固液界面前方的溶质梯度。结合热性能，并与成分过冷准则相类似，A表明，在凝固的早期阶段，金属中的固相生长可能是胞状的，而在搅拌的有机类似物中，凝固的早期阶段是树枝晶。
The conditions of solidification in a stirred bulk liquid are investigated to explain the non-dendritic microstructure of stircast alloys. A model of stirred solidification is presented, which allows a comparison of the solidification behaviour of metal alloys and organic analogues. This shows that nucleation and growth of solid in e bulk liquid is facilitated under the influence of stirring, provided the Prandtl-number is greater than unity. It is shown further that the solute gradient ahead of the solid-liquid interface of floating particles in a bulk liquid is reduced by the fluid flow. Combined with the thermal properties, and in analogy with the constitutional supercooling criterion, A is shown that solid growth in metals is likely to be cellular in an early stage of the solidification, In contrast, in stirred organic analogues, the solidification is dendritic in the early stage.