Multiscale studies and modeling of SPD materials

Recent results of experimental studies and computer modeling of bulk pure metals, subjected to severe plastic deformation (SPD) are presented. Experimental investigations and computer modeling were conducted on different scale levels. Influence of the processing parameters on the flow character of the deformed material and elastic stresses' fields appearing in the die-set is studied on the macrolevel. Conformities of grain and subgrain size evolution, as well as the texture development at SPD were revealed on the mesolevel. On the microlevel as a result of computer simulation there were evaluated densities of the extrinsic grain boundary dislocations; there was analyzed the influence of SPD on the values of static and dynamic atomic displacements and the Debye temperature in the materials under investigation. The obtained results make it possible to explain novel properties, such as simultaneous appearance of high strength and ductility (the SPD paradox), enhanced diffusion properties, low-temperature and/or high-rate superplasticity of bulk SPD nanomaterials. (C) 2004 Elsevier B.V. All rights reserved.