金属间化合物结构材料反位缺陷及其对性能的影响

Antisite Defect in the Intermetallic Structural Materials and Its Effect on the Mechanical Performance

反位缺陷是金属间化合物中的本征点缺陷,它对材料的力学性能、物理性能、化学性能都有重要的影响,在某些情况下成为决定性能的关键结构要素。首先评述了反位缺陷研究理论,基于量子力学的第一性原理方法、EAM法研究结构材料反位缺陷侧重缺陷的物理和化学原理,基于Ginzburg-Landau方程的微观相场法侧重缺陷微结构演化的动态过程。然后,作者通过图解反位缺陷与传输机制之间的关系说明反位缺陷对高温结构材料的积极贡献以及对性能的危害。最后,作者通过评述常见的L12结构和B2结构反位缺陷及第三组元择优占位的研究进展,归纳了结构材料反位缺陷研究存在的问题。

Antisite defects are the intrinsic defects for intermetallic compounds, affecting the materials’ mechanical, physical and chemical properties, and serving as a decisive structural factor to the properties under certain condition. Firstly, the theories for antisite defect study are reviewed, in which the physical and chemical aspects of antisite defect are generally studied by first principle and molecule dynamic methods based on quantum physics, while the temporal-evolution aspects linking to the microstructures are studied using microscopic phase field method based on Ginzburg-Landau equation. Secondly, the graphical demonstration of the antisite defect-diffusion mechanism relation explains the contribution as well as the potential harm of antisite defect to intermetallic structural materials. Finally, the authors summarize the research progress of antisite defect study on L12 and B2 structure as well as the site preference study of dopants, and conclude the deficit about antisite study.