X-Ray diffraction analysis of 99.1% recycled aluminium subjected to equal channel angular extrusion

The microstructure of Equal Channel Angular Extruded (ECAE) 99.1% aluminium was investigated by X-ray diffraction (XRD) analysis. It was found that the XRD peaks showed a significant broadening, which was related to grain refinement and lattice distortions. For microstrain evolution, the saturation value reached after one pass by ECAE can be explained by accumulated strain hardening of the material during plastic deformation. A significant decrease of the lattice parameter was observed after ECAE. This decrease is caused by the grain compression due to its finite size and to the pressure exerted by the grain surface on to the bulk of the grains.