Effect of temperature on formation of β-Sialon whiskers in Al2O3-C materials

The effect of temperature on the synthesis of β-Si3Al3O3N5 whiskers have been researched in this paper. The results show that at the reducing atmosphere, the stable phases of Al4C3, AlN, SiC and β-Sialon existed in the system of Al2O3-Si-Al-C. Under the action of transition metal Ni as catalyst, metal of Al and Si in Al2O3-C refractories is respectively transferred into AlN and SiC. The corresponding temperature is respectively about 1000°C and 1200°C. At 1400°C, the phase of β-Sialon is generated. Without any catalyst, only phases of SiC and AlN can be formed. Short column of AlN as well as whiskers of SiC and β-Sialon could be synthesized when the catalyst exists. The diameter of SiC whiskers and β-Sialon whisker is respectively about submicro and nano meter. The liquid drops in SiC and β-Sialon whiskers show the vapor-liquid-solid growth model.