The Application of the Bifurcation Theory to the Stability of Microstructure and the Improvement of the Superalloys.

分岔理论在微观组织稳定性及高温合金改进中的应用。

基本信息

批准号：
07455280
负责人：
MIYAZAKI Toru
金额：
$ 4.86万
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 (B)
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

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07455280/
关键词：
Elastic interaction Bifurcation theory Ostwald ripening Elastic constraint Interfacial energy Particle size distribution Stability of microstructure Microstructure change

项目摘要

Several interesting phenomena for the formation of microstructure have recently been observed when the materials are elastically constrained. Particularly, the extraordinary behavior in the precipitate coarsening ; deceleration of particle coarsening and splitting of a particle into small ones are typical examples. These phenomena have theoretically supported by "bifurcation theory". In the practical point of view, these phenomena predict an existence of non-over aging materials. The purpose of the present work is to get more wide range information for these phenomena experimentally, and also to give more accurate theoretical background. The results obtained are as follows.(1) Splitting of a particle was newly recognized in Ni-Mo and Fe-Al-Co alloy systems. However, the shapechanging rate of split particles in Fe-Al-Co was remarkably fast. Results from the energetic estimation for the sequence of the particle splitting, the splitting path experimentally observed was consistent with min … More imum-energy path predicted by the theoretical calculation(2) We proposed a new experimental method to investigate the composition dependent phenomena in materials science based on the observation of microstructure changes in a continuous composition gradient field. Utilizing this new method, the equilibrium compositions at the interface of precipitate/matrix could experimentally be obtained for various particle sizes, and thus the Gibbs-Thomson's relation, which is the fundamental low in the precipitates coarsening, was verified experimentally.(3) A new calculation method for the nonlinear diffusion equation was proposed, where the composition dependencies of atomic interaction energy, elasticity and mobility of atoms were taken into account so as to be able to calculate the phase decomposition in the real alloy system. The two dimensional simulations were performed for the phase decomposition in the Fe-Mo binary system. The microstructures calculated were well coincident with experimental facts, and typical features in the strain-induced microstructure changes were successfully calculated. Less

当terials的质量是粒子变速下的，这些现象的差异是在较严重的现象中，这些现象是在粒子上的质量上，这些现象的严重性被观察到了Themoct的观点是，非衰老材料的存在是为了获得更广泛的范围，以实验，并提供更准确的理论背景。 Al-CO非常快，从粒子分裂的估计结果中，观察到的分裂路径是一致的，这是一致的iMum-Energy路径（2）我们提出了一种新的体验方法来研究组合物MENA在基于连续组成梯度中微观结构的材料科学中。在原子相互作用能量的组成依赖性的情况下，原子的弹性和迁移率是Takento帐户，因此能够计算到实际合金系统。事实和GES中的典型特征成功地计算出来