  Microstructural features and mechanical properties of an Al-Mg-Si alloy
processed by high-pressure torsion have been investigated using transmission
electron microscopy, X-ray diffraction, three-dimensional atom probe, tensile
tests and microhardness measurements. It is shown that HPT processing of the
Al-Mg-Si alloy leads to a much stronger grain size refinement than of pure
aluminium (down to 100 nm). Moreover, massive segregation of alloying elements
along grain boundaries is observed. This nanostructure exhibits a yield stress
even two times higher than that after a standard T6 heat treatment of the
coarse grained alloy
