Atomic Structure and Properties of Transformation Interfaces in Metal Alloys

然而，这项研究的目的是对金属合金中的原子结构和相变性质有一个基本的了解。提出了三个主要目标：(1)确定Zr-N合金中ZrN片状和晶粒的原子结构、生长机制和动力学，以与间隙合金相变理论相比较；(2)确定Al-Si/Ge合金中固-液界面的原子结构和性质，以与固-液界面的原子计算和凝固过程中的溶质分配理论相比较；(3)确定了Ti-Al和Fe-Ni合金中块体相变界面的原子结构，并结合结晶学和动力学理论的互补发展，分别预测了取向关系不合理的相间界面和惯性面的结构和行为。本研究采用的主要实验技术包括静态和原位高分辨电子显微镜(TEM)、能量色散X射线能谱(EDXS)、电子能量损失谱(EELS)、静态和原位能量过滤电子显微镜，以及界面结构的原子模拟。这项研究的结果将使材料科学家能够更好地理解和利用界面科学和相变理论的基本原理来开发广泛的技术重要应用的金属合金。它主要通过研究生教育为人力资源做出贡献，为学生提供在相变、界面科学和高分辨率和分析性电子显微镜方面进行最先进研究的机会。

9908855HoweThe purpose of this research is to develop a fundamental understanding of the atomic structure and properties of transformation in metal alloys. Three main objectives are proposed: (1) determination of the atomic structure, growth mechanisms and kinetics of ZrN plates and grains in Zr-N alloy for comparison with theories of phase transformations in interstitial alloy systems; (2) determination of the atomic structure and properties of solid-liquid interfaces in Al-Si/Ge alloys for comparison with atomistic calculations of solid-liquid interfaces and also with the theory of solute partitioning during solidification; and (3) determination of the atomic structure of massive transformation interfaces in Ti-Al and Fe-Ni alloys, combined with complementary development of crystallographic and kinetic theories for predicting the structure and behavior, respectively, of interfaces between phases with irrational orientation relationships and habit planes. The main experimental techniques employed in this research include static and in-situ high-resolution transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDXS), electron energy-loss spectroscopy (EELS), static and in-situ energy-filtering TEM, and atomic modeling of interfacial structure. %%%The results from this research will enable materials scientists to better understand and utilize fundamental principles of interface science and transformation theory in the development of metal alloys for a wide range of technologically important applications. It contributes to human resources primarily through graduate education, providing students the opportunity to perform state-of-the-art research in phase transformations, interface science and high-resolution and analytical transmission electron microscopy.***