SiC_w/MoSi_2的化学炉自蔓延高温合成及反应过程研究

Preparation of SiC_w/MoSi_2 Powder by "Chemical Oven" Self-propagation High-temperature Synthesis and Study of Reaction Process

采用"化学炉"自蔓延高温合成(COSHS)技术,成功地原位合成了SiCw/MoSi2复合粉体。通过在原料中引入Si3N4晶须,在产物中获得了SiC晶须。XRD结果表明,产物中除了主要的MoSi2和SiC相,还含有少量的Mo4.8SiC0.6。研究了中间产物的相组成和反应过程中的温度变化,指出"化学炉"自蔓延合成SiCw/MoSi2复合粉体的反应过程包括如下两步反应:①Mo与Si自蔓延反应生成MoSi2;②Si3N4与C反应生成SiC和N2。

SiC w/MoSi2 composite powder has been successfully in-situ synthesized by ＂chemical oven＂ self-propagation high-temperature synthesis （COSHS） method. The introduction of SiaN4 whisker into the raw material made SiaN4 whisker produced in the combustion product. XRD results show that the combustion product contains a little of Mo4.8 SIC0.6 besides mainly consisting of MoSi2 and SiC phases. The phase composition and temperature variation of the intermediate during the reaction product were studied. It is indicated that the reaction process of ＂chemical oven＂ self-propa- gation high-temperature synthesis of SiCJMoSi2 includes two steps as follows： （1） The self-propagation reaction between Mo and Si makes MoSi2 ; （2） The reaction between SiaN4 and C makes SiC and N2.