Effect of severe plastic deformation on the microstructure and mechanical properties of Al and Cu

The aim of the present study was to examine how various severe plastic deformation processes, in particular hydrostatic extrusion (HE), alter the microstructure and properties of metals with different stacking fault energies, such as copper and aluminum. The mechanical properties of HE processed materials were examined in static tensile test and by microhardness measurements. The results show that the tensile strength and the yield stress increased significantly, especially in Cu. This decrease in strength is due to formation of intersecting deformation bands containing ultra-fine subgrains (Cu) and grains (Al).