Strengthening mechanisms in an ultrafine-grained Al Zn Mg Cu alloy processed by high pressure torsion at different temperatures

The microstructures of an AlZnMgCu alloy processed by high pressure torsion at room temperature and 200 °C were characterized by transmission Kikuchi diffraction and atom probe tomography. Hardening effects of different microstructural features including grain boundaries, dislocations and solute nanostructures were quantitatively calculated using existing models. Compared to the samples processed at room temperature, the samples deformed at 200...