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Micro- and macro-modeling of solidification process

凝固过程的微观和宏观建模

基本信息

批准号：
05239106
负责人：
OHNAKA Itsuo
金额：
$ 51.14万
依托单位：
OSAKA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05239106/
关键词：
solidification melt growth microscopic heat transfer mass transfer phase change structure control functional materials physical properties 擬固

项目摘要

Nagashima's groups has proposed a new method to measure diffusion coefficient and viscosity change near melting temperature, which is difficult to measure with conventional methods. This method uses Rayleigh scattering and Brownian motion of fine particles dispersed in melt. The possibility has been demonstrated for molten KNO_3 and NaNO_3. The data showed the difference between the maximum and minimum viscosity increases near the melting temperature reflecting liquid structure change. Ohnaka's group has made clear the growth mechanism of an organic materials-system which has the similar phase diagram of oxide high temperature superconductors, and developed a micro-model, which can simulate the growth phenomena. Further, they have proposed a new mechanism for particle engulfment at the solid/liquid interface. Hayashi's group has developed a kinetic theory considering microstructure and solidification phenomena for non-facetted free dendritic growth in undercooled liquid and also for th … More e growth near a cooled wall accompanying temperature relaxation and solid phase coarsening. The theory was based on their experimental work on the solidification of Bi-Sn alloy. Tsukada's group has revealed the relationship between growth condition (furnace structure and transport phenomena including thermal stress in crystals) and crystal quality especially micro-cracks for oxide single crystal growth by the CZ method. This work in based on numerical simulation and experimental observation of growth of LiNbO_3 single crystal. Finally, Nakayama's group has made it possible to investigate quantitatively the miniaturization of leads required in three dimensional electric circuits. Namely they developed a method to analyze the solidification process of elongating thin molten alloys and validated their method with experimental works.These works have made more clear the necessity of the micro- and macro-modeling and their combination to improve new materials and devices by using various solidification processes, and some new modeling methods have been developed. Less

Nagashima的团队提出了一种新的方法来测量熔化温度附近的扩散系数和粘度变化，这是传统方法难以测量的。该方法利用了分散在熔体中的细颗粒的瑞利散射和布朗运动。对熔融KNO_3和NaNO_3进行了验证。数据表明，在熔化温度附近，最大粘度和最小粘度的增加差异反映了液体结构的变化。Ohnaka课题组明确了与氧化物高温超导体相图相似的有机材料体系的生长机理，并建立了可以模拟生长现象的微观模型。此外，他们还提出了一种新的颗粒在固/液界面上的吞噬机制。Hayashi的团队开发了一种动力学理论，考虑了过冷液体中无面状自由枝晶生长的微观结构和凝固现象，以及伴随温度松弛和固相粗化的靠近冷却壁的枝晶生长。这一理论是基于他们对铋锡合金凝固的实验工作。Tsukada的团队通过CZ方法揭示了氧化单晶生长的生长条件（炉结构和输运现象，包括晶体中的热应力）与晶体质量特别是微裂纹之间的关系。本工作是在对LiNbO_3单晶生长进行数值模拟和实验观察的基础上进行的。最后，Nakayama的团队已经可以定量地研究三维电路中所需的导线的小型化。也就是说，他们开发了一种方法来分析细长熔融合金的凝固过程，并通过实验工作验证了他们的方法。这些工作更加明确了微观和宏观建模及其结合使用各种凝固工艺改进新材料和新器件的必要性，并开发了一些新的建模方法。少