Structure and Atomic Profile of Grain Boundary Triple Junctions in Tungsten

摘要

The line of triple junction of the general type and special non-CSL grain boundaries was investigated by field ion microscope in high-textured tungsten. Using the controlled field evaporation, the spatial profiles of triple junctions were reconstructed. Atomic-scale wandering of the triple junction line was revealed. The lines of triple junctions of both types of grain boundaries are not perfectly smooth on the atomic scale and have a spatially oscillating character. The triple junction lines consist of the set of kinks with different heights. It was shown that every kink is caused by the existence of the microscopic twist stacking fault on triple junction line. The local penetration of some atomic layers of one crystal in another on grain boundaries within triple junctions was revealed.