Severe plastic deformation of pure Cu and Cu‐rich alloys was found to create a hierarchical combination of fast and ultra‐fast diffusion paths ranging from non‐equilibrium grain boundaries to non‐equilibrium triple junctions, vacancy clusters, nano‐ and micro‐pores, and finally to general high‐angle grain boundaries. Under certain conditions, a percolating network of porosity can be introduced in the ultra‐fine grained materials by a proper mechanical and thermal treatment. This network may offer promising opportunities for creating materials with tailor‐made properties, including combinations of improved mechanical performance with a possibility of self repair using “vascular structures” for atom transport. Applications in such areas as drug eluting bioimplants and lead or polymer eluting materials for reduction of friction based on impregnation of porosity networks with these agents are also envisaged.