Preparation of Sialon/Si_3N_4-SiC Composite Refractories Using KyaniteTailings

摘要

Sialon-SiC composite powders were synthesized from kyanite tailings through the carbothermal reduction nitridation (CRN) technique. Using Sialon-SiC composites to substituteSi_3N_4 composites via the CRN technique synthesize Sialon/Si_3N_4-SiC composite refractories.The phase composition, cross section morphology, and the substituent amount of Sialon-SiC composites impact on refractories mechanical properties were investigated, respectively. The optimized synthesis temperature for the CRN reaction was found to be 1550°C for 4h with the excess carbon 20%.The substituent amount of Sialon-SiCwas 25%, the mechanical properties of Sialon/Si_3N_4-SiC composite refractories reached optimal performance, which bending strength value was41.8 MPa and compression strength value was 61.6 MPa.