Modeling of Deformation Behavior and Dynamic Strain Ageing in ECAP

Equal channel angular pressing (ECAP) is a substantial process for producing ultra-fine grains in bulk metallic materials by means of severe plastic deformation. In this study, microstructure evolution through dynamic ageing characteristics associated with the application of ECAP to Al6061 alloy at high temperature was investigated. The behavior of the material under ECAP, including the dislocation density and cell size evolution as well as precipitation development, was modelled using dislocation density-based model. Followed by ECAP, microstructural observations were undertaken using EBSD. The experimental investigations showed that after two pass of ECAP, a large amount of subgrains with low angle grain boundaries appears in the original coarse grains. The simulated cell size was in good agreement with the experiment, particularly with the observed rapid decrease of the cell size during the second pass slowing down from the forth pass onwards.