15 years have passed since the pioneering works of R.Z.Valiev et al.  introducing the top–down approach of nanostructures in bulk materials. While the first years brought highlights in mechanical properties , recent researches prove outstanding functional properties, like those of shape memory , magnetic , and biomedical nanomaterials . Last results in hydrogen storage and thermoelectric nanomaterials prove that for functional properties low-dimensional SPD-induced lattice defects like vacancy clusters and dislocations can be more beneficial than high-dimensional ones like grain- or phase boundaries .
 R.Z. Valiev, I. Alexandrov, R. Islamgaliev, Progr.Mater.Sci. 45, 103-189 (2000)
 M. Zehetbauer, Y.T. Zhu, Bulk nanostructured materials, Wiley (2009)
 M. Zehetbauer, R. Groessinger, H. Krenn, M. Krystian, R. Pippan, P. Rogl, T. Waitz, R. Wuerschum, Adv.Eng.Mater. 12, 692-700 (2010)
 R. Z. Valiev, Y. Estrin, Z. Horita, T. G. Langdon, M. J. Zehetbauer, Y. T. Zhu, Mater.Res.Lett. 4, 1-21 (2016)