The effect of SiO₂/Al₂O₃ ratio on the structure and microstructure of the glazes from SiO₂-Al₂O₃-CaO-MgO-Na₂O-K₂O system.

Abstract

Ceramic glazes are commonly used to covering of the facing surface of ceramics ware. A well-chosen oxide composition and firing conditions of glazes causes significant improvement of technical parameters of ceramic products. Modern glazes are classified as glass-ceramic composites with different crystalline phases arising during firing. The presence of crystals in the glass matrix is influenced by many factors, especially by oxides molar composition. A crucial role is played by the molar ratio of SiO₂/Al₂O₃. In this work the six composition of glazes from SiO₂-Al₂O₃-CaO-MgO-Na₂O-K₂O system were examined. The only variable is the ratio of the silicon oxideto alumina at a constant content of other components: MgO, CaO, K₂O, Na₂O, ZnO. In order to determine the real phase composition of the obtained glazes research on fluorescence spectrometer (XRF) were done. For structural studies X-ray diffraction (XRD) and spectroscopic in the middle infrared (MIR) were performed. In order to determine the state of the surface (microstructure) research on the scanning electron microscope (SEM) with EDX. The research allowed to determine the influence of SiO₂/Al₂O₃ ratio on the structure and phase composition of glazes and the nature, and type of formed crystalline phases.