Research of Thermal Shock Resistance of Si3N4 and SiC

The study is carried out combing with the production practice in Danjiangkou Hongyuan SiC limited. Si3N4 and SiC were prepared successfully from SiC and Silicon power in nitrogen atmosphere at 1425 degrees C and 1375 degrees C sintering temperature by the serial of techniques, such as ingredients, mixing, molding and drying, respectively. In the actual production, silicon powder content and sintering temperature will directly influence the products of the bending strength and thermal shock resistance. By measuring bending strength, porosities, bulk density, XRD and FESEM, the bending strength and thermal shock resistance of samples were studied mainly by changing sintering temperature and silicon powder content. The results show that bending strength and thermal shock resistance of sample which was added 16% Si powder is best. And bending strength and thermal shock resistance of sample of 1425 degrees C sintering temperature is higher than that of 1375 degrees C sintering temperature.