Dipole drift mechanism of early stages of dislocation pattern formation in deformed metal single crystals

The theories of homogeneous dislocation population instability and formation of periodic dislocation patterns previously suggested were mainly motivated by the proposed analogy between dislocations in a crystal and reaction diffusion chemical systems. As the specific features seem to be essential for understanding of a pattern forming process, a study of detailed dislocation mechanisms and careful comparison with experimental observations are needed. When these mechanisms are understood more completely, it may be seen that they fit into some of the formal schemes that have been proposed. A dislocation dipole drift mechanism is suggested for the clustering of dislocations. This is based on experimental studies of unidirectional (tension, compression) and cyclic plastic deformation of Si--Fe single crystals (Fe--3Si, Fe--0.9Si) measured at temperatures of 295 and 524K. 19 ref.--W.J.G.