以粉煤灰微珠和炭黑为原料,通过微波加热碳热还原法原位合成了SiC/Mullite球体。利用X射线衍射(XRD),场发射扫描电子显微镜(FESEM)对产物进行了物相和结构表征。研究表明:在1100～1300℃之间,微珠表面的SiO2通过固(SiO2)-固(C)反应机理而形成SiC,而内部Mullite依然维持微珠球形骨架,从而形成SiC/Mullite球体。温度高于1300℃时,SiC通过固-液-气机理定向生长为晶须且Mullite亦参与反应,从而使粉煤灰微珠失去其球形形貌。本试验的最佳工艺条件为n(C):n(SiO2)=4.2,温度1200℃下恒温1h。 SiC / Mullite spheres were synthesized in situ by microwave heating and carbothermal reduction method using fly ash microspheres and carbon black as raw materials. The products were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The results show that at 1100-1300 ℃, SiO2 on the surface of microbeads forms SiC by the reaction mechanism of solid - SiO2 while the internal Mullite still maintains the microstructure of the microspheres, forming SiC / Mullite spheres. When the temperature is higher than 1300 ℃, SiC grows to whisker by the solid-liquid-gas mechanism and Mullite also participates in the reaction, so that the fly ash microsphere loses its spherical morphology. The optimum conditions for this experiment n (C): n (SiO2) = 4.2, temperature 1200 ℃ for 1h.