HREM study of 45° [100]quasiperiodic grain boundary in aluminum

Abstract

The structural study of grain boundaries is central to a better understanding of many physical properties of polycrystalline materials. The current body of knowledge on interface structures is almost entirely accumulated from grain boundaries and interfaces with periodic structure. The vast majority of grain boundaries in polycrystalline materials are more general and possess complex atomic structure. Owing to the complex structure of these boundaries, it seems desirable initially to perform structural investigations on boundaries intermediate to periodic and complex general boundaries. Quasiperiodic grain boundaries do not possess translational periodicity, but have some degree of structural order. Thus, they can be considered as a bridge between periodic and general boundaries, and they offer an opportunity to study structures that may be prototypes of more complex boundaries. The structure of quasiperiodic boundaries can be characterized within the framework of the crystallography of quasicrystals. So far, only a few structural studies of quasiperiodic boundaries have been reported. This paper focuses on quasiperiodic boundaries and presents for the first time an HREM study of a 45{degree} [100] twist quasiperiodic grain boundary.