Published in Refractories and Industrial Ceramics
Results are provided for a study of the effect of adding cenospheres (coal combustion waste) on hydration of alumina cement and exothermic reaction parameters. It is established that an increase in addition of cenospheres retards cement hydration, and reduces specimen density after firing at 1200°C up to 40%, strength up to 60% and shrinkage up to ...
Published in Refractories and Industrial Ceramics
Silicon-carbide materials with 5 – 10 wt.% additions of oxides were prepared by liquid-phase sintering at 1860 – 2100 °C. The highest physicomechanical properties were achieved in SiC material containing 20 wt.% of a three-component eutectic composition in the MgO–Y2O3–Al2O3 system. The mechanical characteristics of liquid phase-sintered materials ...
Published in Refractories and Industrial Ceramics
The heterogeneous CaB6–TiB2 powder mixtures were synthesized by reducing the mixture of TiO2 and CaCO3 with boron carbide in vacuum at 1400 – 1650°C. Reaction hot pressing was conducted according to the following regime: 1500°C (synthesis in vacuum) – 1900°C (pressing in Ar). As a result of synthesizing CaB6–TiB2 at mass ratio of 1:1 and 1600°C fol...
Published in Refractories and Industrial Ceramics
The paper provides the results of studying the condition of the working pivot of thrust bearings made of reaction- sintered silicon carbide-based ceramics (SiSiC-ceramics) removed from the seal section of the electrical centrifugal pump system. The working surface of the pivot demonstrates numerous service-induced damages of different origin result...
Published in Refractories and Industrial Ceramics
Experience of using refractory materials based on chrome-oxide in electric glass-melting furnaces for fiberglass production is described. Prospects are noted for using chromium oxide refractories from the point of view of both the service reliability and the furnace campaign duration.
Published in Refractories and Industrial Ceramics
Results are provided for development of refractory concrete based on modified alumina cement using chemical industry waste. A quantitative ratio for mixed filler fractions, the effect of production factors on concrete strength, the dependence of its strength properties on form of filler, and solidification conditions are established. It is shown th...
Published in Refractories and Industrial Ceramics
We show the applicability of the method of designing ceramic tools based on the analysis of their stress-strain state in the choice of ceramics used for the creation of ceramic end milling cutters. We present the relationship between the properties of Al2O3 and Si3N4 ceramics and temperature, displacements, and stresses formed in the cutting edge o...
Published in Refractories and Industrial Ceramics
Hybrid aluminum matrix composites (HAMCs) reinforced with different amounts of ceramic particulates consisting of silicon carbide (SiC) and graphite (Gr) were developed. The amount of ceramic powder was 5 – 15 mass%. Parameters of the hybrid composites such as microstructure, density, and porosity and mechanical properties such as hardness and tens...
Published in Refractories and Industrial Ceramics
The literature on preparation methods and signature features of composites based on transition-metal carbides, nitrides, and borides; covalent compounds (SiC, Si3N4); and Al2O3 reinforced with fibers and whisker crystals is reviewed. The main properties of the fibers and whisker crystals are studied.
Published in Refractories and Industrial Ceramics
The influences of various processing parameters on phase and structure formation during reactive sintering of B4C materials in a Si melt are studied. The reaction of B4C particles and C with molten Si during reactive sintering is examined. Dissolution of B4C particles in the Si melt during reactive sintering has a negative effect. Methods for incre...
