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In this paper, the glazes of a multicomponent system (SiO2-Al2O3-CaO-MgO-Na2O-K2O-BaO-ZnO-ZrO2) were examined. This work focuses on five glazes and the difference between them as the molar ratio of the alkali oxides Na2O/K2O. Analysis of fired glazes focused on changes in phase composition (qualitative and quantitative) microstructure performed during observations made by scanning electron microscopy (SEM). The changing molar ratios were also studied in the structure analysis based on the result of data obtained by middle infrared (MIR) and Raman spectroscopy. The characteristic temperatures of the analyzed glazes were also designated using high-stage microscopy. Surface properties such as the color and roughness of the fired glazes were measured by means of a spectrometer and confocal microscopy as well. The amount and type of crystalline phases with the molar ratio of alkali oxides in the analyzed glazes were changed. In the glazes, the crystalline phase of a solid solution of plagioclase was obtained. The results obtained indicate that glazes with a predominant potassium oxide are characterized by lower characteristic temperatures and greater surface smoothness. Structure analysis indicates a different role for the five-molar ratio of Na2O/K2O. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to determine the effect of the addition of strontium oxide on the recrystallization of zirconium silicate when adding strontium oxide to the glaze composition. Zirconia glazes (four different contents) were prepared, to which strontium oxide was added in amounts of 0, 1, 3, 6, and 12 mass% SrO. The characteristic temperatures of the raw glazes were measured, based on which the maximum firing temperatures were determined. The fired glazes were subjected to a study of their phase compositions and an observation of their microstructures. An analysis of the characteristic temperatures showed a fluxing effect, but it was not as strong for all glazes. Differences in the amount of the crystalline phase of zirconium silicate obtained in the fired glazes, as well as the partial transition of zirconium silicate to the amorphous phase, were observed. Observations of the microstructure clearly indicated an increase in the homogeneity of the distribution of zirconium silicate. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse the thermal properties of glazes from the SiO2-Al2O3-CaO-MgO-Na2O system during the addition of zirconium oxide. The paper describes the effect of the addition of zirconium oxide on characteristic temperatures obtained with a high-temperature microscope and a mechanical dilatometer. Based on these data, the course of the logarithm curves of the viscosity of the glazes was determined on the basis of the Vogel–Tamman–Fulcher model. The analysis of thermal effects during the heating and cooling of glazes was also carried out on the basis of measurements made by means of differential scanning calorimetry and analysis of the phase composition at selected temperatures. The obtained results constitute a comprehensive characteristic of the thermal properties of glazes, in which the amount of zirconium oxide increases—from 0 to 24 mass%. [ABSTRACT FROM AUTHOR]

Composites based on boron carbide (B4C) have drawn attention due to their outstanding physical and chemical properties. Herein, the effect of adding boron, titanium, and both titanium and boron, on the B4C‐based material, is investigated. In addition, the additives' influence on the temperature of composite synthesis and the whole sintering process is evaluated. The Ti–B4C composites are prepared by two different methods: pressureless sintering and hot pressing. The presence of Ti, B, and C as dominant additives in the sintered composites is confirmed by X‐ray diffraction and scanning electron microscopy (SEM). The SEM examination reveals that TiB2 particles formed during the composite process synthesis are distributed homogeneously in the B4C matrix. Mechanical properties, such as hardness, Young's modulus, and fracture toughness are tested, along with the composites' density and porosity. All the sintered samples, regardless of the incorporated additives, are characterized by high mechanical properties, reaching outstanding values in a few cases. The obtained results allow us to state that the usage of a boron and titanium mixture significantly improves the sintering process of composites due to the reactive sintering phenomenon occurring during the composites' preparation. The Ti–B4C composites are classified as ultrahigh‐temperature ceramics materials. [ABSTRACT FROM AUTHOR]