微纳米尺度化学/非化学计量相中反位原子的微观相场研究

项目名称： 微纳米尺度化学/非化学计量相中反位原子的微观相场研究

项目编号： No.51501165

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 董卫平

作者单位： 浙江师范大学

项目金额： 20万元

中文摘要： 反位原子是有序化合物中一种点缺陷，可降低畴界能、层错能等，对力学性能、物理性能、化学性能产生一定影响。非化学计量相有高的反位原子浓度；非化学/化学计量相转化过程反位原子变化最剧烈；有序化合物在纳米、亚微米尺度，反位原子浓度有强的尺度响应性。微观相场方法计算原子在晶格的占位率，研究反位原子具有原理优势。.本申报项目以微纳米尺度化学/非化学计量相为对象，微观相场方法与显微分析实验结合。研究反位原子的亚晶格选择、排列各向异性、相界区聚集的规律，以局部配位有序度表征超点阵亚晶格的局部配位环境；探明局部配位环境、反位原子演化对温度、外应力、弹性取向因子、两相模量差、失配应力、相界区的响应关系；明晰反位原子排列取向性随调制结构、筏状化、解筏、折叠层状化的变化规律；阐明反位原子动力学行为与转变机制、尺度的联系，是晶体缺陷理论中的一个科学问题，可为反位原子定量预测与控制，提供原理参考。

中文关键词： 相场法；晶体缺陷；微纳米尺度；长周期结构；反位原子

英文摘要： Antisite atom, which can lower boundary energy, stacking fault energy, etc., and also have a certain effect on the mechanical, physical and chemical properties, is one kind of point defects in ordered compound. Non-stoichiometric phase has a high concentration of antisite atom; the antisite atoms change most tempestuously during the non-stoichiometric/stoichiometric phase transformation; there is a strong response of antisite atom concentration at nano-/subnanometer scale. Microscopic phase field method has an advantage for studying antisite atom and calculating atomic lattice occupancy..Microscopic phase field method combined with microscopic analysis experiment will be used for studying micro-nanoscale non-stoichiometric/stoichiometric phase in this project. The degree of order will be used to show the local coordination environment of superlattice sublattice in studying sublattice selection, anisotropic arrangement and phase boundary gathered of antisite atom; the local coordination environment , the response relationship of temperature , external stress, elastic orientation factor, the modulus mismatch of two-phase, mismatch stress and phase boundary area of antisite atom will be verified; the arrangement changing with the modulation structure, rafting, rafting solution, folding lamellar of antisite atom will be analyzed; the connection of dynamic behavior of antisite atom and transform mechanism will be clarified, which is a scientific issue in crystal defect theory and can provide the principle for quantitative prediction and control of antisite atom.

英文关键词： Phase Field Method;crystallographic defect;micro-nanoscale; long-period structure;antisite atom