自蔓延高温合成法(SHS)制备SiC颗粒

Fabrication of SiC Particle by Self-propagation High Temperature Synthesis (SHS)

通过SEM、XRD手段对(Si-C-Ti)粉末压块的高温自蔓延反应进行了研究,获得了SiC颗粒。设计压块为内外两层,外层是Ti粉和石墨粉(C),摩尔比为1:1,内层是Si粉和石墨粉,摩尔比也为1:1。结果表明,可以利用压块外层Ti-C反应生成TiC放出的热量引发内层Si-C反应生成SiC颗粒。当外层粉末与内层粉末的质量比为4:1,加热温度为1050℃时,内层Si粉与C粉可以充分反应生成SiC颗粒。

SiC particle was prepared by SHS.The reacted powder preforms were analyzed by SEM(scanning electron microscope)and XRD(X-ray diffraction).The preforms were designed as inner-outer layer structure,where the outer consists of Ti powder and graphite powder with a molar ratio of 1:1,and the inner is composed of Si powder and graphite powder with a molar ratio of 1:1.The results show that the heat released from the formation of TiC in the outer layer can be used to inspire the reaction of Si powder and graphite powder to generate SiC particle.With a weight ratio of 4:1 of the outer and the inner at 1050 ℃,Si powder and graphite powder in the inner layer are fully transformed into SiC particle.