Visualization of the Phase Decomposition Process Based on the Non-liner Diffusion Equation.

基于非线性扩散方程的相分解过程的可视化。

基本信息

批准号：
07555477
负责人：
MIYAZAKI Toru
金额：
$ 0.77万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

A numerical analysis of the diffusion controlled phase transformation based on the non-liner diffusion equation is one of the main subjects in the field of the computer materials science. In the present study, we propose a new analyzing method of the nonlinear diffusion equation ("discrete type diffusion equation"), where the composition dependencies of atomic interaction energy, elasticity and mobility of atoms are taken into account so as to be able to calculate the phase decomposition in the real alloy system. Furthermore, the information of the solute atom occupation probability in atom site is also included in the proposed calculation theory. The proposed new method has a capability of predicting not only the phase decomposition in the disordered phases but also the other phase transformations such as the stress-induced precipitates coarsening, order/disorder phase transitions, phase decompositions in ordering alloys, the formation process of tweed structures, and so on. The purpo … More se of the present work is to reveal the nature of the phase transformation by visualizing the phase decomposition process. The detail behavior in diffusion controlled phase decomposition is calculated on the basis of the "discrete type non-linear diffusion equation". The results obtained are as follows.The two dimensional computer simulations were performed for the phase decomposition in the Fe-Mo, Fe-Cr, Al-Zn, and Cu-Co binary alloy systems on the basis of the new method. The thermodynamic data of phase diagram for these alloy systems was used in the present simulation. The microstructures theoretically calculated were well coincident with experimental facts of these alloy systems. Particularly, the typical features in the strain-induced microstructure changes were successfully calculated. Furthermore, we prepared the "Introduction Video" for the phase transformation by visualizing the calculated results based on the computer simulations. The detail behavior of the phase decompositions was presented by using the VTR,and this result will be very useful for the education in the field of materials science and engineering. Less

基于非线扩散方程的扩散控制相变的数值分析是计算机材料科学领域的主要主题之一。在本研究中，我们提出了一种非线性扩散方程（“离散类型扩散方程”）的新分析方法，其中原子相互作用能，原子的弹性和迁移率的组成依赖性被考虑在内，以便能够计算实际合金系统中的相位分解。此外，提议的计算理论还包括原子位点可溶性原子发生概率的信息。所提出的新方法不仅可以预测无序阶段中的相位分解，而且还可以预测其他相变的相变，例如压力诱导的精确度，秩序/无序相变，相位分解，用于订购合金，Tweed结构的形成过程等。目的……当前工作的更多SE是通过可视化相分解过程来揭示相变的性质。扩散控制相位分解中的细节行为是根据“离散型非线性扩散方程”计算的。所获得的结果如下。根据新方法，对Fe-MO，Fe-CR，al-Zn和Cu-Co二元合金系统的相分解进行了二维计算机模拟。这些合金系统的相图的热力学数据用于演示模拟。理论上计算的微结构与这些合金系统的实验事实吻合。特别是，成功计算了应变引起的微结构变化中的典型特征。此外，我们通过根据计算机模拟可视化计算的结果来为相变的“引言视频”编写。使用VTR提出了相分解的细节行为，该结果对于材料科学和工程领域的教育非常有用。较少的