Microstructural evolution during friction stir-processing of pure iron

Microstructural evolution during friction stir-processing of pure iron was studied. The development of grain structure was found to be a complex process driven mainly by grain subdivision, but also involving the geometrical effect of strain and local grain-boundary migration. The evolution of deformation-induced grain boundaries was found to be linked to the global straining state and texture evolution as well as to slip patterns within the grains in which they develop. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.