Physical, chemical, and mechanical properties of nanostructured materials
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PHYSICAL, CHEMICAL, AND MECHANICAL PROPERTIES OF NANOSTRUCTURED MATERIALS K. J. Kurzydlowski Nanocrystalline materials have special physical, chemical, and mechanical properties. To a significant extent, these properties are attributed to a high density of grain boundaries and other defects in nanocrystalline compounds. We study the microstructure and mechanical properties of nanomaterials (Al, Al-alloys, Cu, Ni, Ti, and stainless steel) and nanocomposites (Al2 O3 / Ni – P) by the methods of transparent and scanning electron microscopy, X-ray diffraction analysis, and microhardness and tensile tests. The experimental methods include the procedures of measuring the electric and corrosion resistances. The materials are prepared by using contemporary methods, namely, by hydrostatic extrusion (nanometals) and by sintering ceramic powders covered with Ni–P nanoparticles under high pressure by using the procedure of nonelectric chemical metallization (Al2 O3 / Ni – P nanocomposites).
The present work was prepared to commemorate the 80th birthday Prof. Volodymyr V. Panasyuk who executively researches (among others) into the properties of engineering methods, such as fracture mechanics and strength of materials. Over the last few years, the scientific collaboration has been established between the Karpenko Physicomechanical Institute of the Ukrainian National Academy of Science and the Faculty of Material Sciences and Engineering (FMSE) at the Warsaw University of Technology, and this contribution to the special issue of hydrogen degradation of materials was prepared to outline the research projects currently performed in our laboratories. This was done with a strong conviction that the exchange of information will strengthen the existing collaboration and may help in understanding new initiations. At the same time, it is hoped that this survey of the results obtained in the projects in action provides useful information on the state-of-the-art of the respective research fields. Introduction Ultrafine-grained and nanograined crystalline materials exhibit attractive properties, such as high strength combined with reasonable ductility and toughness [1–10]. These microstructures can be obtained in metallic materials by the methods of severe plastic deformation (SPD) [11 – 20]. The following SPD methods have been extensively used: Equal-Channel Angular Pressing (ECAP), High-Pressure Torsion (HPT), Cyclic-Extrusion Compression (CEC), and Accumulative Roll Bonding (ARB). It was shown ([1–4, 14–20]) that, for sufficiently large strains, these methods produce an average grain size of less than 200 nm. Recently, hydrostatic extrusion has been used to refine grain sizes in a number of pure metals and alloys as well as the SPD technology and others techniques for manufacturing of nanomaterials. Promising results were obtained for high-pressure processing of ceramic–metal nanocomposites under high pressure. This new composite have interpenetrating phases and exhibit multifunctional properties. Warsaw University of Technology, Warsaw,
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