IN SITU REACTION SINTERING AND CHARACTERIZATION OF MULLITE-CORDIERITE COMPOSITES

Mullite-cordierite composites with different mullite to cordierite ratios were prepared by an in situ reaction sintering method.First,a cordierite started powder (C powder) and a mullite started powder (M powder) were prepared by mixing kaolin,alumina,and talc based on the theoretical chemical composition of cordierite and mullite,respectively.Then,the C powder and the M powder were mixed together at different ratios,formed and sintered to produce a series of mullite-cordierite composites.In order to promote the formation of mullite crystals,the V2O5 additive was introduced.The phase composition,microstructures,thermal and mechanical properties of the composites were characterized by X-ray diffraction etc.The sintering temperature of the composites with only cordierite and mullite phases can be as low as 1 380 ℃.The cordierite and mullite crystals in the composite grow well,and their thermal shock resistance is good.