沉淀合金中反位缺陷演化的微观相场模拟

项目名称： 沉淀合金中反位缺陷演化的微观相场模拟

项目编号： No.51301067

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 张建军

作者单位： 华北电力大学

项目金额： 25万元

中文摘要： 沉淀合金的沉淀相中可形成以原子排列反位为特征的点缺陷，称为反位缺陷；反位缺陷降低沉淀相的反相畴界能、层错能，削弱沉淀相的抗位错切截能力，对合金的塑性、强度、抗蠕变性等产生重要的影响。探明沉淀相中反位缺陷的形成和演化规律，可为合金成分和组织设计、热处理工艺优化、服役能力评定，提供原理支撑。 本项目采用微观相场法，以原子在晶格格点的跃迁几率为场变量，模拟镍基、铝基沉淀合金的反位缺陷演化，与微观分析实验结合。研究亚稳区至失稳区合金中反位缺陷演化规律，沉淀相尺度、组元间原子尺寸差对反位缺陷演化的影响，同相和异相有序畴界上的反位缺陷演化；得出成分、温度、晶体结构、畸变能等对反位缺陷演化的影响规律，明晰反位缺陷演化对沉淀序列、涨落机制的响应关系，探明反位缺陷演化与相结构转变的内在联系，以序参数等定量描述反位缺陷演化，揭示反位缺陷演化的动力学机制，属于晶体缺陷理论和沉淀理论中的科学问题。

中文关键词： 沉淀相；反位缺陷；微观相场；晶体缺陷；沉淀合金

英文摘要： Precipitation phase of precipitation alloy can formate point defect which characterized by the antisite arrangement of atoms,that is known as antisite defects. Antisite defects can reduce the precipitation phase antiphase boundary energy,stacking fault energy,and weaken the resistance capacity of dislocation cuting. It have significant effect on ductility, strength,and creep resistance. If the law of antisite defect formation and evolution can be investigated, it will provide theoretical support for the design of alloy composition and organization, the optimization of heat treatment process, and the assessment of service capacity. This project uses the microscopic phase field method, which the transition probability of atom on lattice grid is the field variables. This method can simulate the antisite defects evolution of nickel base,aluminum base alloy, and it combinates with microscopic analysis experimentals. In this project the main tasks include: the evolution law of antisite defects in metastable and instabilty alloy, the influence of antisite defects evolution by precipitates scale and atomic size differences, and the evolution of antisite defects in the ordered domain interface boundary.Through the research, the influence of antisite defects evolution by the compostion, temperature, crystal structure, an

英文关键词： Precipitation phase；antisite defects；microscopic phase field；crystal defect；precipitation alloy