EBSP investigation of microstructure and texture evolution during equal channel angular pressing of aluminium

Commercial purity aluminum (99.5% Al) was deformed by equal channel angular pressing (ECAP) using up to 10 passes using route Bc. The evolution of microstructure and texture was characterized using the electron back scattered pattern technique. By use of the stereological parameter length per unit area (LA), it was found that on average a sub-micron grain size is developed only after 10 passes. Significant heterogeneity exists however in the sample and in some places a sub-micron grain size is not developed even after 10 passes. The texture strength was found to increase with increasing strain over the strain range investigated. Comparison of microstructural evolution with other deformation modes suggests that ECAP is more similar to cyclic extrusion-compression than to cold-rolling.