Microstructural evolution in the low strain amplitude multi-axial compression (LSA-MAC) after equal channel equal pressing (ECAP) of aluminum

Low strain amplitude multi-axial compression (LSA-MAC) increases the work hardening capacity and uniform ductility of Aluminum after Severe Plastic Deformation (SPD) through Equal Channel Angular Pressing (ECAP). The mechanisms associated with this processing after ECAP are analyzed. LSA-MAC after 1 ECAP pass in Aluminum softens the material and is connected to the stabilization of the dislocation structures induced by ECAP into a configuration displaying an increased fraction of High Angle Grain Boundaries (HAGB). This occurs for a lower total imposed strain than that through a sequence of high strain ECAP passes or high strain amplitude multi-axial compression (HAS-MAC).