Technological Aspects of Synthesizing Ceramic Coatings by Flow-Through Micro-Arc Oxidation

Refractories and Industrial Ceramics - The paper introduces a promising technology for utilizing a traditional scheme for implementing a flow-through micro-arc oxidation method to restore localized...     

Granulometric Analysis of Powder Materials Used for Producing Samples by Method of Selective Laser Melting

Metallurgist - The paper discusses the aspects of granulometric and morphological analysis of powders used in the technology of selective laser melting. Studies have been carried out to obtain...     

Optical bleaching of freshly spun polyacrylonitrile fibres

Conclusions A new effective optically bleaching substance of the cationic type in liquid form has been developed.The advisability of using it to bleach freshly spun polyacrylonitrile fibre by a continuous method has been demonstrated.Translated from Khimicheskie Volokna, No. 2, pp. 42–43, March–April, 1990.     

Structure and thermophysical properties of aluminum-matrix composites

The microstructure and thermophysical properties of aluminum-matrix composites have been studied, in which a granulated Al–Zn–Mg–Cu alloy has been used as the matrix, and SiC particles taken in the amounts of 10, 20, and 30 vol % have bee used as the filler. It has been shown that, with an increase in the amount of the filler, the temperatures of the solidus and liquidus of the composites and the values of the thermal expansion coefficient and density increase, whereas the heat capacity, thermal conductivity, and thermal diffusivity decrease. The heat capacity of the composite depends on the amount of the filler: upon heating from 25 to 500°С, the heat capacity of the composite with 10 vol % SiC increases by only 16%, while that of the composite with 20 vol % SiC increases by 19%; and, at 39 vol % SiC, it increases by 36%.     

Development of a Method for Evaluating Alumina Ceramic Material the Wear Resistance

Refractories and Industrial Ceramics - Amethod is developed for rapid evaluation of the wear resistance of ceramic materials by changing the roughness parameter Rt. The method is tested...     

Averaging principles applied to logistic equations with rapidly oscillating delays

The problem about local dynamics of the logistic equation with a rapidly oscillating timeperiodic piecewise constant coefficient of delay has been considered. It has been shown that the averaged equation is a logistic equation with two delays. A stability criterion for equilibrium points has been obtained. The dynamical properties of the original equation are considered provided that the critical case of the equilibrium point stability problem has been implemented. It has been found that an increase of delay coefficient oscillation frequency may lead to an unlimited process of steady-mode birth and death.     

Structural and optical properties of thin In2O3 films produced by autowave oxidation

Cubic-phase In₂O₃ films are produced by the autowave oxidation reaction. Electron microscopy and photoelectron spectroscopy of the atomic profiles show that the samples are homogeneous over the entire area and throughout the thickness, with the typical grain size being 20–40 nm. The optical and electrical properties are studied for In₂O₃ films fabricated at different pressures in the vacuum chamber. In the wave-length range from 400 to 1100 nm, the transparency of the films was higher than 85%; the resistivity of the films was 1.8 × 10^?2 Ω cm.