Thermodynamic aspects of liquid phase sintering of SiC using Al2O3 and Y2O3

A thermodynamic dataset for the Al -C-O-Si-Y system was used for calculations of multicomponent, multiphase reactions. Some aspects of the liquid phase sintering of silicon carbide using alumina and yttria sintering additives were analyzed. The phase relations in the SiC-Al2O3, SiC-Al2O3-SiO2 and SiC-Y2O3-SiO2 systems were calculated. Phase fraction diagrams, isopleths, isothermal sections, and potential phase diagrams are presented to illustrate the reactions between silicon carbide and sintering additives. The effect of Ar inert gas as an additional component and the related volume change of the gas phase were considered. In addition, the influence of surface silica on silicon carbide powder is taken into account.