It seems there is no special need to comment on the term 'nanostructure' now, when one often meets the 'nano' words not only in scientific journals but even in newspapers. Moreover, today they are even to be heard in TV and radio programmes. In academic science, where the terms 'nanostructure' and 'nan otechnology' have been extremely popular since the early 1990s, they have been successfully extended to the sphere of economics and business, and now to politics. This is quite natural because nanostructures and nanotechnolo gies will surely serve as a basis for the most advanced and highest technology production in the nearest and probably also the remote future. Hence, the struggle to create and occupy its markets is already under way. In this respect, it is of great interest to review data on the dynamics of U. S. Federal Goverment expenditure for nanotechnology [1,2]. In the fiscal years 1997 and 2002, expenditure was approximately US$116 and US$ 697 million, respectively. In the fiscal year 2004, the President's request for US federal in vestment in nanoscale science, engineering and technology is about US$ 849 million [2]. The indicative budget allocated to the Thematic Priority enti tled 'Nanotechnologies and nanosciences, knowledge-based multifunctional materials and new production processes and devices' for the duration 2002- 2006 of the sixth EU Framework Programme for Research and Technological Development is EUR 1300 million [3].

Nanocrystalline materials exhibit exceptional mechanical properties, representing an exciting new class of structural materials for technological applications. The advancement of this important field depends on the development of new fabrication methods, and an appreciation of the underlying nano-scale and interface effects. This authored book addresses these essential issues, presenting for the first time a fundamental, coherent and current account at the theoretical and practical level of nanocrystalline and nanocomposite bulk materials and coatings. The subject is approached systematically, covering processing methods, key structural and mechanical properties, and a wealth of applications. This is a valuable resource for graduate students studying nanomaterials science and nanotechnologies, as well as researchers and practitioners in materials science and engineering.

Recently, it was reported that nanostructured materials processed under high pressure by HPT and ECAP have an extraordinary combination of both high strength and high ductility, which are two desirable, but rarely co-existing properties. These findings indicate that high-pressure is a critical factor that can be employed to process nanostructured materials with superior mechanical, and possibly also physical, properties. It is the objective of this workshop to review our current knowledge, identify issues for future research, and discuss future directions on the processing and properties of nanostructured materials via SPD techniques, with a special emphasis on high-pressure effects. The 42 peer-reviewed papers in this book cover areas of high pressure effect on the nanostructure and properties of SPD-processed materials, fundamentals of nanostructured materials, development of high-pressure SPD technologies for commercializations, recent advances of SPD technologies as well as applications and future markets of SPD-processed nanostructured materials.

Material processing techniques that employ severe plastic deformation have evolved over the past decade, producing metals, alloys and composites having extraordinary properties. Variants of SPD methods are now capable of creating monolithic materials with submicron and nanocrystalline grain sizes. The resulting novel properties of these materials has led to a growing scientific and commercial interest in them. They offer the promise of bulk nanocrystalline materials for structural; applications, including nanocomposites of lightweight alloys with unprecedented strength. These materials may also enable the use of alternative metal shaping processes, such as high strain rate superplastic forming. Prospective applications for medical, automotive, aerospace and other industries are already under development.

These proceedings of the "Second International Conference on Nanomaterials by Severe Plastic Deformation" review the enormous scientific avalanche that has been developing in the field over recent years. A valuable resource for any scientist and engineer working in this emerging field of nanotechnology.

This book concentrates on both understanding and development of nanocrystalline materials. The original relation that connects grain size and strength, known as the Hall-Petch relation, is studied in the nanometer grain size region. The breakdown of such a relation is a challenge. Why and how to overcome it? Is the dislocation mechanism still operating when the grain size is very small, approaching the amorphous limit? How do we go from the microstructure information to the continuum description of the mechanical properties?

Proceedings of a symposium sponsored by the Shaping and Forming Committee of the Materials Processing and Manufacturing Division (MPMD) and the Mechanical Behavior Committee (Jt. SMD/ASM-MSCTS) of the Structural Materials Division (SMD) of TMS (The Minerals, Metals & Materials Society) and held during the 2002 TMS Annual Meeting in Seattle, Washington February 17-21,2002.