The application of the bifurcation theory to the microstructure changes and its stability.

分岔理论在微观结构变化及其稳定性中的应用。

基本信息

批准号：
04452270
负责人：
MIYAZAKI Toru
金额：
$ 4.54万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04452270/
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 alloys, ceramics and semiconductors are elastically constrained. Particularly, the extraordinary behavior in the precipitate coarsening ; deceleration of particle coarsening, stopping the particle coarsening and splitting of a particle into plural small particles are typical examples. These phenomena have theoretically supported by "bifurcation diagram", proposed by us. In the practical point of view. This phenomena imply an existence of non-over ageing work is to get even if heated at high temperature for atom to diffuse. The purpose of the present work is to get a more wide range of experimental examinations and also to give more accurate theoretical back ground.The results obtained for this academic years are as follows.(1)Hitherto the splitting of a particle was recognized in Ni-base and Iron-base alloys such as Ni-A1, Ni-Si, Fe-A1-Co and so on. However, the splitting behavior bet … More ween the Ni-base alloys and Iron-base ones was different. The shape changing rate of splitted particles was remarkably fast in Iron base alloys.(2)In the Fe-Si-V system which has a large eigenstrain, the uniformalization of particle size, the deceleration of particle coarsening and particle alignment to <100> direction were experimentally recognized. Especially these behaviors become dominant as the volume fraction of precipitates increase. Inevitability of such the characteristic coarsening is theoretically discussed on the bifurcation diagram.(3) Kinetic path calculated for the precipitate nucleation process was consistent with minimum-energy path predicted by the theory of the system free energy proposed by us. This result indicates that the energy analysis is very useful even for the early stage of the phase decomposition. Therefore we calculated the time developmence of particle coarsening on the base of the energetic estimation. As the calculation results, more accurate behavior of the particle coarsening in elastically constrained systems is obtained. Less

当合金，陶瓷和半导体受到弹性限制时，最近观察到了微观结构形成的几种有趣现象。特别是，珍贵的浓缩行为的非凡行为；粒子变硬的减速，阻止粒子粗化和将粒子分裂为复数小颗粒的碎片是典型的例子。这些现象通过我们提出的“分叉图”具有理论上的支持。从实际的角度来看。这种现象暗示着不过老化工作的存在是即使在高温下加热以使原子弥漫。本工作的目的是获得更广泛的实验检查，并提供更准确的理论背景。（1）迄今为止，在Ni-base和Iron-base合金中识别了粒子的分裂，例如Ni-A1，Ni-A1，Ni-Si，Ni-Si，Fe-A1-CO等。但是，分裂行为下注……更多我们的Ni碱合金和铁碱碱是不同的。在铁碱合金中，拆分颗粒的形状变化速率非常快。（2）在Fe-Si-V系统中，具有较大的本征膜，粒径的均匀化，颗粒块的均匀化，颗粒变质和粒子对准<100>方向的降低。特别是随着沉淀的体积分数的增加，这些行为变得占主导地位。理论上在分叉图上讨论了这种特征性变色的必然性。（3）针对精确核过程计算的动力学路径与我们提出的系统自由能理论预测的最小能量路径一致。该结果表明，即使对于相分解的早期阶段，能量分析也非常有用。因此，我们计算了粒子在能量估计基础上的粒子变稠的时间发展。随着计算结果，获得了在弹性约束系统中颗粒的更精确的行为。较少的