A Research on Microscopic and Macroscopic Mechanics in Melting/Solidification Processes Incorporating Moving Boundary/Interface, and Its Application to Welding and Bonding

结合移动边界/界面的熔化/凝固过程的微观和宏观力学及其在焊接和粘接中的应用研究

基本信息

批准号：
10305011
负责人：
INOUE Tatsuo
金额：
$ 25.34万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

Analyses on melting and solidification processes are carried out by microscopic, macroscopic and mesoscopic viewpoints, in order to reveal the mechanism and to build up thermo-mechanical theory on the phase transformation processes incorporating moving boundary and interface, such as welding and joining. Molecular dynamics method and the finite element method are used as microscopic and macroscopic method, respectively, while phase-field method and crystal plasticity theory are applied to mesoscopic analysis. The summary is as follows :(1) Microscopic Analysis by Molecular Dynamics Method : The motions of atoms around the interface of solid and liquid are analyzed and the stability of the interface, anisotropy in the interface energy depending on crystal orientation are evaluated. And the preferred orientations of crystal growth are determined from the relation between the orientation and interface energy.(2) Mechanical Properties of Welded Heat Affected Zone : Deformation in the micro … More scopic area in the weld metal, heat-affected zone, and parent material of Mo.9Cr-1Mo steel is measured by the micro-grid method, and the relation between hardness, structural change and strain is revealed to be clear.(3) Analysis of Crystal Growth Process by Phase-Field Method : Crystal growth process is analyzed by the phase-field method in which mechanical and thermophysical properties and anisotropy based on the molecular dynamics simulation are introduced. Various modes of dendritic crystals are obtained by the combination of the parameters. These results made it possible to observe the dynamic process of the pattern formation, and some phenomena such as initial stage of crystal growth, which is difficult to experimentally observe, are demonstrated.(4) Finite Element Analysis Based on Crystal Plasticity Theory : Deformation behavior in the heat-affected zone was simulated by the finite element method, and the results obtained by the model in which grain size and anisotropy was introduced were revealed to be corresponding to experimental results. These results are supporting the relation obtained in (2). Less

通过微观，宏观和介观观点进行了融化和凝固过程的分析，以揭示机制并建立在结合移动边界和界面（例如焊接和连接）的相变过程上的热机械理论。分子动力学方法和有限元方法分别用作显微镜和宏观方法，而相位方法和晶体可塑性理论则应用于介观分析。摘要如下：（1）通过分子动力学方法进行显微镜分析：分析原子围绕固体和液体界面的运动，并评估界面的稳定性，界面的稳定性，界面能量中的各向异性取决于晶体方向。晶体生长的首选方向是由方向和界面能量之间的关系确定的。（2）焊接热影响区的机械性能：微型的变形……在焊接金属，热影响区域中的范围更大，MO.9CR-1MO钢的固定材料通过微粒变化和结构变化（3.9CR-1MO钢）进行测量（3.9CR-1MO钢），并揭示了晶体变化，结构变化是（3（3）。相位方法：通过相位方法分析晶体生长过程，在该方法中，引入了基于分子动力学模拟的机械和热物理特性以及各向异性。通过参数的组合获得各种树突晶体的模式。这些结果使观察模式形成的动态过程成为可能，并且证明了一些现象，例如晶体生长的初始阶段，很难在实验上观察到。（4）基于晶体可塑性理论的有限元分析：通过有限元方法模拟了晶体尺寸和植物尺寸的结果，从而模拟了晶体可塑性理论的变形行为。这些结果支持（2）中获得的关系。较少的