多元线性化合物的扩散系数矩阵、扩散生长的相场模型及其在铝合金微结构定量表征中的应用

项目名称： 多元线性化合物的扩散系数矩阵、扩散生长的相场模型及其在铝合金微结构定量表征中的应用

项目编号： No.51474239

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 矿业工程

项目作者： 张利军

作者单位： 中南大学

项目金额： 82万元

中文摘要： 材料制备过程中微观结构演变的定量描述是材料学核心科学问题之一。基于关键实验的相场模拟是对微结构演变进行定量描述一种行之有效的方法。对于工业合金中重要的多元线性化合物，迄今仍缺乏描述其扩散生长的相场模型及扩散系数矩阵建立的科学方法。本项目拟以Al-Mg-Si合金为研究对象开展如下研究：（1）构建多元线性化合物的平均热力学因子，并集成扩散偶实验、原子尺度模拟及唯象扩散模拟获得Al-Mg-Si合金时效过程所含稳定/亚稳相的扩散系数矩阵；（2）建立能合理描述多元线性化合物生长的相场模型；（3）结合关键实验对Al-Mg-Si合金时效过程微结构演变进行定量相场模拟。项目的完成可望为含线性化合物的多元合金微结构演变提供可采纳的相场模型，并实现对Al-Mg-Si合金时效过程微结构演变的定量描述，使材料制备过程微结构演变定量描述前进关键的一步。

中文关键词： 多元线性化合物；扩散及相图热力学；相场方法；微结构；Al-Mg-Si合金

英文摘要： Quantitative description of the microstructure evolution during materials preparation process is one of the core scientific problems in material science. The phase-field simulation coupled with key experimental verification is one effective approach to realize the quantitative description of the microstructure evolution. For the important multicomponent line compounds in industrial alloys, there has been still a lack of the phase-field model for describing their diffusion growth as well as the scientific approach for establishing their diffusivity matrix. The present proposal intends to choose the Al-Mg-Si alloys as the target, and the following researches are to be performed: (1) Development of average thermodynamic factor for multicomponent line compounds, and establishment of the diffusivity matrix for all the stable/metastable phases during aging process in Al alloy by integrating the diffusion couple experiment, atomistic simulation and phenomenological diffusion model; (2) Development of a phase-field model for reasonably describing the growth of the multicomponent line compounds; (3) Quantitative phase-field simulation of the microstructure evolution in Al-Mg-Si alloys during aging process by coupling the phase-field method and key experiments. It is highly expected that the completion of this project will provide a general phase-field model for description of microstructure evolution in multicomponent alloys with line compounds, and realize the quantitative description of microstructure evolution in Al-Mg-Si alloys during aging process, resulting in critical step forward for quantitative description of microstructure evolution during material preparation.

英文关键词： Multicomponent line compound;Diffusion and thermodynamics;Phase-field method;Microstructure;Al-Mg-Si alloys