Effect of cobalt powder morphology on the properties of WC-Co hard alloys

The effect of cobalt powder morphology on the microstructure of WC-Co hard alloys produced by sintering cobalt + tungsten carbide powder mixtures has been studied using X-ray diffraction, laser diffraction, scanning electron microscopy, density measurements, and Vickers microhardness tests. The results indicate that, under identical sintering conditions, the densest and most homogeneous microstructure is formed in hard alloys sintered using cobalt powders consisting of rounded particles. The use of cobalt powders with dendritic morphologies impedes the homogenization of Co + WC powder mixtures and preparation of pore-free WC-Co hard alloys. © 2013 Pleiades Publishing, Ltd

EFFECT OF Al ADDITION ON THE PHASE COMPOSITION, MICROSTRUCTURE, AND MICROHARDNESS OF NANOCRYSTALLINE WC CERAMICS

Nanocrystalline WC and WC-Al powders were prepared by high energy ball milling and mixing in a planetary ball mill. The phase composition, microstructure and microhardness of ceramics sintered from these powders have been investigated

EFFECT OF MECHANICAL ACTIVATION AND SOLID-STATE SYNTHESIS TEMPERATURE ON THE COMPOSITION AND GRAIN SIZE OF TUNGSTEN CARBIDE

This study reports that the preliminary mechanical activation of the W and C powder mix prior to the synthesis allows for obtaining a single-phase WC at significantly lower tempera-tures. This results in smaller mean grain sizes but also increases the amount of free carbon in the WC powder

Идентификация человека по голосу для системы дистанционного обучения

This article is about identification of human voice and speech recognition. These developments can be applied in the field of distance education.Представлены различные технологии идентификации человека по голосу и распознания речи. Данные разработки могут быть применены в сфере дистанционного обучения

PREPARATION AND STUDY OF THE PROPERTIES OF NANOCRYSTALLINE NIOBIUM CARBIDE

Nanocrystalline niobium carbide powders of various sizes were obtained by high-energy milling. Carrier gas hot extraction method was applied for the determination of oxygen in nanopowders. It was found that a decrease in particle size leads to an increase in the total amount of oxygen in the sample

OXYGEN DETERMINATION IN NANOCRYSTALLINE NIOBIUM CARBIDE

Carrier gas hot extraction method was applied for the determination of oxygen in nanocrystalline niobium carbide. Measurement parameters ensuring correct and reproducible results were determined and experiments using linear heating were performed

SIMULATION OF X-RAY DIFFRACTION PROFILE REFLECTIONS OF THE SAMPLES WITH A BIMODAL PARTICLE SIZE DISTRIBUTION

The profile of X-ray diffraction peaks in the spectra of the powder mixtures was simulated. Various mixtures of microcrystalline and nanocrystalline powders of hexagonal (sp.gr. P6m2) tungsten carbide WC were studied. According to the preliminary estimates, the profile of the Bragg reflection can determine heterogeneity of the grain size

PREPARATION OF VCу NANOPOWDERS OF VARIOUS PARTICAL SIZES AND COMPOSITION

Nanocrystalline powders of nonstoichiometric disordered cubic (sp. gr. Fm-3m) vanadium carbide VCy were synthesized by high-energy ball-milling and subsequent vacuum annealing. The obtained nanocrystalline powders have the particles ranging from 80 to 20 nm and different stoichiometry within its homogeneity region of VC0 6 5 to VC0 .875- The nanopowders were characterized by X-ray diffraction and scanning electron microscopy.Исследование выполнено в ИХТТ УрО РАН за счет гранта Российского научного фонда (проект № 14-23-00025)

Visiontouch — новая технология интерактивных проекций для учебного процесса

The technology that allows to recognize any touch on the projection without using the interactive whiteboard is presented. Product is recommended for use in education.Представлена технология, позволяющая распознавать любые прикосновения на проекции без использования интерактивной доски. Разработка рекомендована для использования в образовательном процессе

OXIGEN FORMS IN NANOCRISTALLINE POWDERS OF TANTALUM CARBIDE

The determination of oxygen by carrier gas hot extraction was applied for nanopowders of tantalum carbide. Using different measurement modesallowed making assumptions about the forms of existence of oxygen in this system