INFLUENCE OF BURNING CONDITIONS ON β-SiAlON BOND OF A1_2O_3-REFRACTORIES

摘要

Six test series of p-sialon bonded Al_3O_3-refractories with the same composition have been sintered at different temperatures and in different atmospheres. A reasonable phase composition was ascertained. For the sintering two different electric furnaces were used, one with graphite heating elements (furnace G) and the second one with MoSi_2 heating elements (furnace M). The samples were sintered in nitrogen atmosphere at temperatures from 1400 to 1650°C. The oxygen partial pressure in furnace M was defined by the use of a carbon bed.The results of the experiments show that P-sialon can not be prepared at a sintering temperature of 1400°C. At 1650°C the different atmospheres lead to the formation of different phases in the matrix. These phases are p-sialon, X-sialon, mullite, glassy phase, SiC and carbon beside the main component Al_2O_3.