Defect Structure and Properties of Nanomaterials, 2nd Edition

Chapter 3

Defect Structure in Bulk Nanomaterials Processed by Severe Plastic Deformation

Abstract

Contamination- and porosity-free bulk nanostructured materials can be processed from coarse-grained workpieces by severe plastic deformation (SPD). During SPD procedures the grain refinement is usually associated with the formation of large amount of lattice defect, such as grain boundaries, dislocations, and vacancies. In this chapter, the evolution of defect structure during SPD processing is reviewed. At high imposed strain in SPD processing, the grain and crystallite sizes reach their minimum values and the dislocation density gets saturated. Although there is no strict correlation between the grain or crystallite size and the dislocation density, ...