A Study of Grain Boundary Structure and Transformations Utilizing the Faceting Phenomenon in a Cooper-Bismuth Alloy

本研究采用原子级平坦的晶界刻面 这是由于铋掺杂的 铜作为一个模型系统，以研究 晶界成分和结构之间的关系 双组分合金的结构。 主要实验 工具是传统的和高分辨率的透射电子 显微镜（HREM）。 方法是从晶体学角度 两个邻接晶粒中的每一个中的小平面的取向， 一个晶粒对特定的取向差，然后确定 的铋原子在小平面的HREM的位置。 这些结果 与原子计算相比。 刻面类型的演变 作为时间和退火温度的函数进行检查。 %%% 这项研究提供了有关原子尺度的重要信息 晶界偏析的结构和化学性质。 粮食 边界在确定物理 多晶材料的特性。

This research employs the atomically flat grain-boundary facets which form as the result of solute segregation in bismuth-doped copper as a model system with which to study the relationship between grain boundary composition and structure and the evolution of structure in a two component alloy. The principal experimental tools are conventional and high-resolution transmission electron microscopy (HREM). The approach is to identify crystallographic orientations of the facet planes in each of two abutting grains for a grain pair of specific misorientation, and then determine the location of the bismuth atoms in the facets by HREM. These results are compared to atomistic calculations. Evolution of facet types is examined as a function of time and annealing temperature. %%% This research provides important information about the atomic-scale structure and chemistry of segregation at grain boundaries. Grain boundaries play an important role in determining the physical properties of polycrystalline materials.