INVESTIGATION OF THE INFLUENCE OF YTTERBIUM OXIDE ON PHASE COMPOSITION AND SHS PARAMETERS OF COMPOSITIONS BASED ON SILICON NITRIDE

Using the method of self-propagating high-temperature synthesis (SHS) SHS compositions based on the Si3N4–Yb2O3 system were obtained. Synthesis by combustion was carried out in a nitrogen atmosphere at a pressure of 4 MPa in a reactor with a volume of 30 liters. The mass of the loaded mixture was 3 kg. It has been established that the amount of ytterbium oxide in the charge affects the combustion temperature and the phase composition of the synthesis products. With an increase in the proportion of ytterbium oxide in the mixture, the content of the alpha phase decreases, and the secondary phases are represented by quaternary ytterbium-silicon oxynitride and ytterbium disilicate.