以金属Al粉、Si粉、SiO2粉及不同粒度SiC为原料,按Z=2 Sialon结合相为25%的方案进行配料,凝胶注模法成型试样,在1450℃、1500℃、1550℃下常压氮化,保温15min~120min制备Sialon-SiC材料。采用氮化反应动力学模型对氮化烧结实验结果进行了动力学分析研究。实验分析结果表明:在〈30min的氮化过程的初级阶段为化学反应过程;在30min~75min的中期阶段为化学反应与扩散的混合控制过程;在75min~120min的后期阶段为扩散控制过程。在1550℃时氮化率最高、氮化反应速率常数最大.氮化反应活化能最小。
The Sialon-SiC material has been prepared at normal pressure in 1450E-1550℃ for 15-120 rain in N2 by gel casting with Al, Si, SiO2, and various granularities of SiC as raw material, which is based on the value of Z is equal to 2 of 25 percent SiAION phase in Sialon-SiC material. This paper study the nitidation dynamic on test result of nitidation sintering by the model of nitridation reaction. The test analysis result shows that the primary stage sintered for less than 30 rain belongs to chemical reaction process, the middle stage sintered for 30-75 min to mixed process of chemical reaction process and dispersing, the last stage sintered for 75-120 rain to dispersing process. Nitriding rate, nitridation reaction constant and activation energy are the optimal when the sintering temperature is 1550℃.