Passivation of Compacted Samples Made of Pyrophoric Iron Nanopowders during Their Interaction with Air

Combustion, Explosion, and Shock Waves - Various macrokinetic modes of interaction (self-ignition or combustion) of compact samples from nonpassivated (pyrophoric) and passivated iron nanopowders...     

Plastic deformation of the plastic matrix–hard inclusion composite system during high-temperature gas extrusion

The results of investigations of the production of abrasive rod or wire diamond tools by high-temperature gas extrusion are presented. The versions of preparation of an initial metallic workpiece filled with a mixture of abrasive diamond grains are considered. The forming of plastic materials with hard inclusions, which is caused by deformation redistribution in the volume and is accompanied by the formation of pores and discontinuities adjoined to the hard inclusions, is considered. The results obtained demonstrate the prospects of application of high-temperature gas extrusion for the production of diamond tools for various purposes.     

Effect of Al2O3 on the Microhardness of AMg2/Graphite Nanocomposite Powder Gas Dynamic Coatings on Aluminum Alloys

Metal Science and Heat Treatment - Mechanically synthesized hybrid powders of the AMg2/graphite + Al2O3 system and coatings deposited by cold gas dynamic spraying from these powders are studied....     

Effect of Temperature on the Shrinkage Rate of Compacts Composed of Nanoparticles

An expression describing the shrinkage rate of compacts composed of nanoparticles is obtained under the assumption that nanoparticles undergo fluctuation melting. The expression derived has the following form: dY/dt = Aexp(−(T _M + q)/T), where dY/dt is the shrinkage rate; T _M is the melting temperature of nanoparticles; T is the sintering temperature; and A and q are constants that depend on the material, the initial porosity, and the size of nanoparticles in the compact. The experimental data on the shrinkage rate of compacts composed of copper and nickel nanoparticles 70 nm in size are compared with the shrinkage rates calculated according to the derived expression. This comparison shows that the experimentally measured shrinkage rates are close to the calculated values.Original Russian Text Copyright © 2005 by Fizika i Khimiya Stekla, Stepanov, Alymov, Evstratov.     

Synthesis in a High-Energy Planetary Mill of Granules Based Onaluminum Alloy Containing Nanocrystalline Graphite

Metallurgist - Bulk nanocomposite granules based on AlMg2 alloy, containing nanocrystalline graphite, are prepared by mechanical synthesis using a high-energy ball mill. Structural and phase...