It is known that work pieces with nanocrystalline structure condition have much higher performance than those with an ordinary structure. There are known number of techniques for manufacturing of nanocrystalline materials in powder condition however a question of manufacturing bulk pieces in the same nanocrystalline state mentioned is that compaction and synthesizing of nanocrystalline powders ...

The properties of nanocrystalline materials are essentially determined by the grain size and the properties of the grain boundaries of the respective material. Using PAC for the investigation of nanocrystalline materials new information about structural properties and, in case of nanocrystalline semiconductors, electronic properties are obtained. In combination with “classical” experimental tec...

We report transmission electron microscope observations that provide evidence of deformation twinning in plastically deformed nanocrystalline aluminum. The presence of these twins is directly related to the nanocrystalline structure, because they are not observed in coarse-grained pure aluminum. We propose a dislocation-based model to explain the preference for deformation twins and stacking fa...

Nanocrystalline (nc) materials can be defined as solids with grain sizes in the range of 1–100 nm. Contrary to coarse-grained metals, which become more difficult to twin with decreasing grain size, nanocrystalline face-centered-cubic (fcc) metals become easier to twin with decreasing grain size, reaching a maximum twinning probability, and then become more difficult to twin when the grain size ...

A mechanism of the transport of nanocrystalline doped calcium carbonatephosphates through the membrane on the model of interaction with phospholipids is considered. Nanocrystalline doped calcium carbonate – phosphates are perspective to transport of the cations in a living cell. Kinetics of the synthesis of nanocrystalline doped calcium carbonatephosphates are non-linear kinetics. Biomaterial b...

In this paper, the performance of the cutting tool with nanocrystalline multilayer coatings (TiN+TiAlN) for machining of superalloy Inconel 718 in the dry and wet conditions was studied. The multi layer TiN and TiAlN with nanocrystalline structure was applied by physical vapor deposition technique (arc evaporation) on the WC-Co inserts. The results of the ball on disc wear test and the machinin...

Nanocrystalline cerium oxide is an attractive material for catalysis of environmentally hazardous gas-phase species such as sulfur dioxide and carbon monoxide. Oxygen vacancies in cerium oxide are believed to coordinate and aid in the transfer of oxygen ions between the reactive species. We have sought to characterize these defects in nanocrystalline cerium oxide as a function of the heat treat...

Natural bone consists of hard nanostructured hydroxyapatite (HA) in a nanostructured protein-based soft hydrogel template (ie, mostly collagen). For this reason, nanostructured HA has been an intriguing coating material on traditionally used titanium for improving orthopedic applications. In addition, helical rosette nanotubes (HRNs), newly developed materials which form through the self-assemb...

In recent years, near-nano (submicron) and nanostructured materials have attracted increasingly more attention from the materials community. Nanocrystalline materials are characterized by a microstructural length or grain size of up to about 100 nm. Materials having grain size of 0.1 to 0.3 mm are classified as submicron materials. Nanocrystalline materials exhibit various shapes or forms, and ...

We measured the phonon density of states (DOS) of nanocrystalline Fe by resonant inelastic nuclear g-ray scattering. The nanophase material shows large distortions in its phonon DOS. We attribute the high energy distortion to lifetime broadening. A damped harmonic oscillator model for the phonons provides a low quality factor, Qu, averaging about 5, but the longitudinal modes may have been broa...