非晶态莫来石纤维析晶动力学的研究  

Kinetics of Aluminum Silicate Fiber Crystallization

作　　者：李荣缇[1] 潘伟[1] 

机构地区：[1]清华大学材料科学与工程系精细陶瓷与先进工艺国家重点实验室,北京100084

出　　处：《材料导报》2001年第9期68-71,共4页Materials Reports

摘　　要：用非等温差热分析研究了莫来石纤维(Al_2O_379wt%)的析晶动力学行为,它在高温下的析出相为莫来石晶体。随着升温速率β的增大,析晶反应初始温度 T_0、最大析晶速率 dx/dt_p以及达到最大析晶速率时的温度 T_p 都逐渐增大。在 JMA 模型的基础上,用四种方法系统分析了非晶态硅莫来石纤维的析晶反应过程动力学,确定该析晶反应的最佳动力学参数为 E_e=625kJ/mol,n=1.61,k_0=4.98×10^(19)(s^(-1))。该析晶反应是扩散生长控制的,晶粒的生长介于一维生长和二维生长之间,并且在析晶反应的过程中形核速率是下降的。The crystallization behavior and kinetics of aluminum silicate glass fiber(Al_2O_3 79wt%)were in- vestigated using a non-isothermal DTA method.The precipitation phase of aluminum silicate glass fiber was mullite. With increase of the heating rate β,the initial crystallization temperature T_0,maximum crystallization temperature T_p and maximum crystallization rate dx/dt_p are rising.The crystallization kinetic parameters were investigated using several kinetic models and the optimal kinetic parameters for crystallization process of aluminum silicate glass fiber are E_e=652kJ/mol,n=1.61,k_0=4.98×10^(19)(s^(-1)).It is suggested that the crystallization process of aluminum silicate galss fiber should be controlled by the diffusion growth,all kinds of grain shapes should be growing from small dimen- sions,and the nucleation rate should be decreasing in the crystallization process.

关 键 词：非晶态莫来石纤维 析晶动力学 非等温DTA分析 晶粒生长 玻璃化转变温度 

分 类 号：TQ343[化学工程—化纤工业]