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化的原子转化与对运输特性的影响相关联。目的是建立对温度诱导的晶粒边界相变的基本理解，以及纯金属晶界以及杂质隔离引起的晶粒边界以及对界面特性的直接影响。晶界的结构和过渡将通过异常校正的透射电子显微镜（TEM）在原子量表上进行探索，其宏观运输特性将通过示踪剂差异实验来探测。实验结果将通过对所选界面的结构和扩散的原子模拟进行系统的支持。隔离诱导的晶界转变及其对动力学特性的影响将在Cu-Ag，Cu-Co和Cu-ZR系统中进行探索。定义的[001]倾斜晶界将通过散装双晶的生长获得，从而可以根据需要调整晶粒不良和晶界倾斜度。这也使从原子水平到µm长度尺度的尺度桥接表征。获得的Cu晶界将在与AG，CO和ZR的受控条件下掺杂，并且Advanced TEM可以解决其温度依赖性结构，隔离和过渡。通过示踪剂差异实验探测了相同的晶界，以确定其动力学特性并行并垂直于倾斜轴。此外，还将探索晶界倾斜度倾斜度对晶界转变及其传输特性的影响，以建立对晶界转化对界面特性的影响的整体理解。