Disclination-structural-unit model of quasiperiodic tilt boundaries of finite extent

A disclination-structural-unit model of quasiperiodic tilt boundaries of finite extent in polycrystalline and nanocrystalline materials is suggested. In the framework of the model, the elastic energy density of finite quasiperiodic boundaries is calculated. The results of the model are discussed and compared with those obtained by methods of the dislocation-structural-unit model and with experimental data. It is found that use of the disclination approach is effective, in particular, in the description of tilt boundaries and their ensembles in nanostructured materials.