The processing and mechanical behaviour of bulk nanostructured materials are one of the most interesting new fields of research on advanced metallic systems. Many nanocrystalline materials possess near theoretical strength and exhibit high values for fracture toughness, resilience, and fatigue resistance. There continues to be interest in these nanomaterials for use in biomedical, structural, and mechanical applications, and there now are a high number of research programs worldwide, too. The book focusses on techniques and the outstanding properties of materials with ultrafine grained structure, and also considers the basic understanding behind. Only since recently such materials can be produced in massive shape which opens their use in commercial and industrial applications.