Technological features of receiving and research of high density ceramic materials on the basis of silicon carbide

Abstract

The article is devoted to the establishment of regularities of synthesis and technological aspects of the formation of composite ceramics based on silicon carbide and aluminum nitride by the method of hot pressing, as well as the study of its structural properties. The paper presents the results of the study of the microstructure and elastic properties of ceramics based on silicon carbide, obtained by hot pressing at temperatures up to 2170 K and pressures up to 35 MPa, of various compositions (0.9SiC - 0.1AlN; 0.7SiC - 0.3AlN; 0.5SiC - 0.5AlN; 0.3SiC - 0.7AlN; 0.1SiC - 0.9AlN), the average density of which is 3.21 g/cm3. The microstructure of the obtained samples was studied with a scanning electron microscopy. Elastic moduli of SiC-AlN hot-pressed ceramic materials were determined by the method of resonant ultrasonic spectroscopy (RUS) depending on the composition. Our data on Poisson’s ratio are in good agreement with the literature data and are well described by linear approximation. The values of Young’s modulus are noticeably lower than the literature ones. The values of the elastic moduli lie below the additive right line of ceramic SiC and AlN with zero porosity, which is related to the influence of the porosity of our samples.