Correlating the atomisitic nature of grain boundary phase transformations to their macroscopic kinetic properties

将晶界相变的原子性质与其宏观动力学特性相关联

• 批准号: 467491887
• 负责人: Professor Dr. Sergiy Divinski
• 金额: --
• 依托单位: Physical and Life Sciences Directorate
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/467491887?language=en
• 关键词: Correlating; atomisitic; nature; grain; boundary

The present proposal aims to correlate the atomistic origins of structural transformations at metallic grain boundaries with their impact on the transport properties. The goal is to establish a fundamental understanding of temperature-induced grain boundary phase transformations in pure metallic grain boundaries, as well as those induced by impurity segregation, and their direct impact on interfacial properties. The structure and transitions of grain boundaries will be explored at the atomic scale by aberration-corrected transmission electron microscopy (TEM) and their macroscopic transport properties will be probed by tracer diffusion experiments. The experimental results will systematically be supported by atomistic simulations of structure and diffusion of selected interfaces. Segregation-induced grain boundary transitions and their effect on the kinetic properties will be explored in the systems Cu-Ag, Cu-Co and Cu-Zr. Defined [001] tilt grain boundaries will be obtained by bulk bi-crystal growth, allowing to tailor grain misorientation and grain boundary inclination on demand. This also enables the scale bridging characterization from the atomic level to µm length-scales. The obtained Cu grain boundaries will be doped under controlled conditions with Ag, Co and Zr and advanced TEM resolves their temperature dependent structure, segregation and transitions. The same grain boundaries are probed by tracer diffusion experiments to determine their kinetic properties parallel and perpendicular to the tilt axis. Furthermore, the impact of deviations in grain boundary inclination on grain boundary transitions and their transport properties will also be explored to establish a holistic understanding of the impact of grain boundary transformations on interfacial properties.

本提案旨在将金属晶界结构转变的原子起源与其对输运特性的影响联系起来，目标是建立对纯金属晶界以及那些温度诱导的晶界相变的基本理解。通过像差校正透射电子显微镜（TEM）在原子尺度上探索晶界的结构和转变，并通过示踪扩散来探测它们的宏观输运特性。实验结果将系统地得到所选界面的结构和扩散的支持，并且将在 Cu-Ag、Cu-Co 和 Cu-Zr 系统中探索它们对动力学性质的影响。定义的[001]倾斜晶界将通过体双晶生长获得，允许根据需要定制晶粒取向差和晶界倾斜，这也使得能够从原子水平进行尺度桥接表征。 Cu 晶界将在受控条件下掺杂 Ag、Co 和 Zr，先进的 TEM 可以解析它们的温度依赖性结构、偏析和转变，通过示踪扩散实验探测相同的晶界，以确定获得的动力学。此外，还将探讨晶界倾斜度偏差对晶界转变及其传输特性的影响，以全面了解晶界转变对界面特性的影响。