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Design of a cold crucible and characteristics of melting and levitating on materials with a high temperature melting

冷坩埚设计及高温熔化材料的熔化和悬浮特性

基本信息

批准号：
01850149
负责人：
ASAI Shigeo
金额：
$ 10.94万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01850149/
关键词：
Cold Crucible Electromagnetic Processing of Materials Plasma Self-Propagating High Temperature Synthesis Silicon High Melting Point Materials Intermetallic Compounds Boundary Element Method 連続鋳造化学的活性材料単結晶電磁場理論解析液体急冷

项目摘要

1. To evaluate the effects of design parameters of a cold Crucible, a three-dimensional mathematical model was developed where the boundary element method was employed to solve the magnetic field distribution around a cold crucible system. The fundamental information for design was obtained by use of the model.2. The new hybrid process which combines a cold crucible and a plasma was proposed. This process can melt materials such as oxide, carbide and nitride, an electric conductivity of which is relatively low in solid state but increase drastically at the melting point. Furthermore, it was found that the process was useful for melting materials with high melting point such as WC, Mo, and Nb. The relations between operating conditions of the process and physical properties were clarified by use of mathematical model developed for the process and by the experimental results.3. Another hybrid process which combines the SHS(Self-propagating heatfront synthesis)reaction and the cold crucible are developed. By use of the process, TiAl intermetallic compound which is promising to use as the high temperature resistance materials in the future generation, could be successfully melted. The process has advantages to suppress Al vaporization by controlling the atmosphere pressure, to allow the precise control of compositions due to electromagnetic mixing and to decrease the oxygen content due to high vaporization rate of suboxides.4. By developing a mathematical model of SHS reaction, the condition for which the heat wave can propagate in the steady state was derived.5. A new type of the cold crucible was designed for concentrating magnetic field and its applicability to the zone melting process was studied by the ways of the theoretical analysis and the experiments.

1.为研究冷坩埚设计参数对磁场分布的影响，建立了冷坩埚系统的三维数学模型，采用边界元法求解冷坩埚系统周围的磁场分布。利用该模型获得了设计的基础信息.提出了一种新的冷坩埚-等离子体复合工艺。该方法可以熔化诸如氧化物、碳化物和氮化物的材料，其导电率在固态下相对低，但在熔点下急剧增加。此外，还发现该工艺可用于熔化具有高熔点的材料，例如WC、Mo和Nb。通过建立的工艺数学模型和实验结果，阐明了工艺操作条件与物性的关系.提出了一种将自蔓延热锋合成（SHS）反应与冷坩埚相结合的复合工艺。利用该工艺可以成功地熔炼出具有发展前途的TiAl金属间化合物耐高温材料。该方法具有通过控制气氛压力来抑制Al蒸发、由于电磁混合而允许精确控制组成以及由于低氧化物的高蒸发速率而降低氧含量的优点。通过建立自蔓延高温合成反应的数学模型，推导出了在稳态下热波能够传播的条件.设计了一种新型的集中磁场冷坩埚，并通过理论分析和实验研究了其在区域熔炼工艺中的适用性。