Characterization, modeling and microstructure of composite aluminium alloy specimens after ECAP

The ECAP, the Equal Channel Angular processing or pressing, in general allows to modify the properties of materials at the microstructure level. In the proposed investigation, the composite specimens in aluminium alloy were subjected to different ECAP passes. The characterization after ECAP was performed by means of warm compression tests between 200 and 300°C with different ram velocities. By a coupled experiment-analytical methodology the friction effect was quantified and the stress-strain curves reported for different temperatures, deformation velocities and ECAP conditions. The friction effect was isolated and the flow behaviour trend of the alloy under different conditions modeled with two models. In particular a model in which the friction variable was considered and the other one in which the friction variable was completely neglected were built and tested. The countertrends in the initial ECAP passes were analyzed by microstructure investigation. The behaviour of the alloy under the considered conditions can be effectively modeled once identified the correct parameters in terms of pre-deformation.