The basic features of quasi-periodic grain boundaries in nanocrystalline and polycrystalline solids were considered. It was shown that quasi-periodic boundaries could serve as effective sources and sinks of lattice dislocations in nanocrystals. A special strengthening effect in deformed nanocrystalline and polycrystalline solids was considered which was attributed to the presence of quasi-periodic boundaries in such solids.

Quasiperiodic Boundaries and Special Strengthening Effect in Nanocrystals. I.A.Ovidko: Nanostructured Materials, 1995, 6[5-8], 743-6