Microstructural evolution in an aluminum solid solution alloy processed by ECAP

Samples of an Al-1% Mg solid solution alloy were processed by equal-channel angular pressing (ECAP) at room temperature for totals of 1-12 passes and the microstructures of the processed samples were examined using orientation imaging microscopy. The results demonstrate the alloy achieves a reasonably stable microstructure after 6 passes through the ECAP die with an ultimate equilibrium grain size of similar to 700 nm. Measurements show both the fraction of high-angle boundaries and the average boundary misorientation increase with increasing numbers of passes up to 6 passes but thereafter there is only a minor additional increase up to 12 passes. (C) 2011 Elsevier B.V. All rights reserved.