Development of the new method to investigate the phase transformations based on the computational scientific approachs.

开发基于计算科学方法研究相变的新方法。

基本信息

批准号：
09242105
负责人：
MIYAZAKI Toru
金额：
$ 39.94万
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 on Priority Areas
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

(1) Computer simulation of the phase decomposition based on the non-linear evolution equation (Miyazaki).The time evolution of the phase decomposition in the real alloy system (such as Al-Zn, Cu-Co, Fe-Mo, Fe-Al-Co, Fe-Cr and III-V compound semiconductor, etc.) was investigated experimentally. The dynamics of the microstructure changes for those alloy systems were simulated on the basis of the Phase-field Method developed by the present research. The morphological feature of the calculated microstructures were in good agreement with the experimental results.(2) Computational analysis of the critical phenomena (Mohri).The susceptibility and relaxation time for the order-disorder phase transition near the transition point were investigated by the Cluster Variation and Path Probability Method, numerically. The susceptibility diverged toward the spinodal disordering temperature when the transition type is first order. It is well known that the critical slowing down will occur at the second order phase transition point. We found that the similar phenomenon will take place even for the first order phase transition by our calculation. The flatness of the free energy at the vicinity of the transition point would be the origin for the phenomena above mentioned.(3) Theoretical investigation for the rubber-like behavior of Martensitic transformation (Ohta).The rubber-like behavior of Martensitic transformation was simulated, successfully. The constitutive equations for the stress and strain field were deduced from the phase field type evolution equations with considering the twin boundary motion. The stress-strain curve and its frequency dependence were predicted by the numerical simulation.

（1）基于非线性演化方程（Miyazaki）对相位分解的计算机模拟。实际合金系统（例如Al-Zn，Cu-CO，Fe-MO，Fe-MO，Fe-MO，Fe-Al-CO，Fe-Al-CO，Fe-CR和IIII-V Amiconductor等）的相位分解时间演变。这些合金系统的微结构变化的动力学是根据本研究开发的相位方法模拟的。计算出的微观结构的形态学特征与实验结果非常一致。（2）关键现象的计算分析（MOHRI）。在群集变异和路径概率方面，研究了在过渡点附近的阶阶阶相变位的易感性和放松时间。当过渡类型是一阶时，敏感性朝着旋转无序温度的差异。众所周知，临界减速将发生在二阶相变点。我们发现，即使我们的计算对于一阶相变，也将发生类似的现象。过渡点附近的自由能的平坦度将是上述现象的起源。（3）成功模拟了马氏体转化的橡胶样行为的理论研究。考虑到双边界运动，从相位场类型的演化方程中推导了应力和应变场的本构方程。通过数值模拟预测了应力 - 应变曲线及其频率依赖性。