17 research outputs found
Composite Ceramics Based on Garnet-type Oxide Y2.5Nd0.5Al5O12 and Silicon Carbide. Preparation. Properties
We have obtained powders of garnet-type complex oxide Y2.5Nd0.5Al5O12 – x vol.% SiC (x = 0, 10, 20) using wet chemistry techniques. The ceramics based on the studying compounds were sintered using Spark Plasma Sintering (SPS) (
Tungstate Based Ceramics Obtained By Spark Plasma Sintering Method – Possible Material for Consolidation of Radioactive Wastes’ Components
The Spark Plasma Sintering method was used to produce high-density ceramics from tungstates SrWO4 and NaNd(WO4)2 with scheelite structure. These compounds are proposed as possible matrices for the consolidation of radwaste components. Powder samples were obtained by coprecipitation method and studied by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). After sintering, the samples retained their phase identity (scheelite structure). The total duration of sintering was ∼ 13-15 min, the relative density was reached ∼ 92, 99%.
Keywords: Tungstates, RW, Spark Plasma Sintering, high density, microstructur
Study of Phase Composition Homogeneity in Depth of Tungsten Carbide Ceramics Produced by Spark Plasma Sintering
Tungsten carbide (WC) ceramics obtained by spark plasma sintering were investigated by layer-by-layer X-ray diffraction analysis. It was found that the phase composition of WC ceramics varies with the distance from the sample surface.The study was supported by the Russian Foundation for Basic Research under Scientific Project №20-33-90214
High-Temperature Deformation of Ceramics Based on Tungsten Carbide with Different Grain Sizes
The aim of this work is to study the high-temperature deformation behavior of sintered tungsten carbide ceramics with different grain sizes. It is shown that the creep activation energy in UFG tungsten carbide with a grain size of ~0.15 μm, sintered from plasma-chemical nanopowder, is ~31 kTm.Работа выполнена при поддержке гранта РФФИ №20-33-90214
X-RAY PHASE ANALYSIS OF HARD ALLOYSOBTAINED BY SPARK PLASMA SINTERING OF POWDER WC +10 %Co+1 %Cr3C2
Parameters of powder WC +10 % Co +1 %Cr3C2sintering modes that provide the increase of grain size in sintered ceramics and greater wetting of tungsten carbide grains with cobalt were determined.Определены параметры режимов спекания порошка состава WC+10 %Co+1 %Cr3C2, приводящие к увеличению размера зерна в спеченной керамике и достижению большего смачивания зерен карбида вольфрама кобальтом.Работа выполнена при финансовой поддержке гранта РФФИ № 19-03-00925
STUDY OF THE PHASE CONTENT HOMOGENEITY OF CERAMICS OBTAINED BY SPARK PLASMA SINTERING OF POWDERWC + 10 %Co
The phase content of ceramic samples WC + 10 % Co was studied. Samples were obtained in different sintering modes. The isothermal holding in the sintering process did not affect on the depth distribution of the main phases.Исследован фазовый состав керамических образцов, полученных в разных режимах спекания порошка WC+10 %Co. Проведение изотермической выдержки в процессе спекания не повлияло на распределение основных фаз по глубине образца.Работа выполнена при финансовой поддержке РНФ в рамках гранта № 18-73-10177
Preparation of NZP-type Ca0.75+0.5xZr1.5Fe0.5(PO4)3-x(SiO4)x powders and ceramic, thermal expansion behavior
Ca0.75+0.5xZr1.5Fe0.5(PO4)3–x(SiO4)x (x = 0–0.5) solid solutions have been synthesized by a sol–gel process and characterized by X-ray diffraction, IR spectroscopy, and differential scanning calorimetry. As expected, the synthesized phosphatosilicates
crystallize in a NaZr2(PO4)3-type structure (trigonal symmetry, sp. gr. R3c). The
thermal expansion of the solid solutions has been studied by high-temperature Xray diffraction in the temperature range from 25 to 800°C. Their thermal expansion parameters have been calculated and analyzed as functions of composition. Highdensity ceramics based on the Ca0.875Zr1.5Fe0.5(PO4)2.75(SiO4)0.25 phosphatosilicate
have been produced by spark plasma sintering and their structure and properties
have been studied in detail.This work was supported by the Russian Science Foundation, project no. 16-13-10464: Advanced ceramic like mineral materials with improved and adjustable service characteristics: design, synthesis, study.Peer reviewe
Prospects of Using Social Networks to Form the Culture of High School Students
The article discusses the features of modern youth that determine their behavior in the Internet, presents the results of a survey of high school students about their usage of social networks and video hosting.В статье рассмотрены особенности современной молодежи, определяющие ее поведение в интернет-пространстве, приведены и проанализированы результаты опроса старшеклассников об использовании ими социальных сетей и видеохостингов
Generation of agent simulation models by using process mining methods on the example of E-learning process
Thermal expansion of scheelite-like molybdate powders and ceramics
NaxSr1 – 2xNdxMoO4 (x = 0–0.5, Δx = 0.1) solid solutions with the scheelite structure have been synthesized for the first time and their crystallographic parameters have been determined as functions of composition and temperature. Their thermal expansion coefficients have been determined in the temperature range 25–1000°C: αa = (12.9–14.9) × 10–6 °C–1 and αc = (24.9–25.9) × 10–6 °C–1. Using spark plasma sintering at tmax ≈ 872–985°C and τ ≈ 650–750 s, we have prepared ceramics with relative densities in the range 97–99%.This work was supported by the Russian Science Foundation, project no. 16-13-10464: Promising Mineral-Like Ceramic Materials with Improved and Controlled Functional Characteristics: Development, Synthesis, and Characterization