β－Sialons粉料的合成实验

SYNTHETIC EXPERIMENT OF β-SIALON POWDER FROM KAOLIN

用高岭土为基本原料，加入活性碳及Ｆｅ（ＮＯ３）３·９Ｈ２Ｏ催化剂压制成混合物小圆饼，在氮气（Ｎ２）氛中经碳热还原氮化反应合成β－Ｓｉａｌｏｎｓ粉料。实验结果经Ｘ射线物相分析法测定反应生成物的物相组成及其相对含量，分析研究混合原样中碳与高岭土的比例、保温湿度和保温时间等实验因素对合成产物组分的影响。研究结果表明，实验参数原样中碳含量、保温温度和保温时间彼此关联，它们与产物中物相的关系十分复杂，直接影响着生成物中的物相及其相对含量的变化。本文仅就实验工艺参数对合成产物的影响进行初步探讨。

This poper reports the result of Synthetic experimental for β'-Sislon powder from an inexpensive raw material kaolin in our laboratory. Kaolin and carbon with few Fe(NO3)3· 9H2O catalyst were wet mixed, dried, and pelletized. Every Pellet (≌1 g, =1. 3 cm) was heated in nitrigen atmosphere.The mixtures were converted to β-Sialon powder by carbothermic reduction and nitridation at relatively low temperatures (T/K=1 523-1 723).Phase analysis of products was performed by X-ray diffraction method. The present paper describes the rate of reaction of kaolin-carbon mixtures as a function of temperature, carbon content and heating time. The relationship among the factors and their influence for the formation of β-Sialon are very complex.The formation and the phase transformation during the synthetic process of β-Sialon are also discussed.