中文摘要：

在1500℃、1600℃、1650℃和1750℃氩气中保温3 h,使Fe-Si在石墨基板上熔化并敷展,分别在熔层表面获得SiC颗粒层、SiC颗粒与晶须混合层、SiC晶须层和SiC腾空薄膜。XRD分析确定所有产物均为3C-SiC;TEM和SAED分析表明,SiC晶须为3C-SiC单晶,生长方向为[111]。基于上述结果,提出不同温度下C与熔体中的Si经不同反应路径,生成不同形貌SiC的反应机理：低温时（≤1500℃）,Fe提高了熔体中C的饱和溶解度,以液-固（LS）反应生成SiC颗粒;较高温度时（1500-1750℃）,借助Fe的催化作用,以气-液-固（VLS）机理生成SiC晶须;更高温度时（≥1750℃）,气-液-固（VLS）变得无序,生成SiC腾空连续膜。

英文摘要：

By melting Fe-Si flux on a graphite template at 1500℃C, 1600℃, 1650℃ and 1750℃ for 3 hours in Ar atmosphere, SiC grains, SiC grain and whisker complex, SiC whiskers and SiC aerial films were obtained, respectively, over the solidified flux, The XRD proves that all of them are 3C-SiC. The TEM and SAED further confirm that the SiC whiskers belong to single crystalline 3C-SiC, and the growth direction is [111]. Based on these results, the growth mechanisms for the SiC with different morphologies are proposed. At the low temperature （≤1500℃）, Fe enhanced the carbon solubility in the melt, and Si reacted with saturated C by the liquid-solid （LS） mode to produce SiC grains. In the higher temperature range （1500- 1750℃ ）, the SiC whiskers were grown by the vapor-liquidsolid （VLS） mode and Fe acted as the catalyst. At the temperature of 1750℃, the SiC aerial film was formed due to also the VLS mode but in a less ordered way,