Temperature field regulation and growth mechanism of SiC fiber during microwave synthesis with catalyst assistance.

Microwave heating is considered an environmentally friendly and cost-effective method for sintering. Temperature field regulation and local hotspots are gaining widespread attention during microwave sintering. In this study, sol-gel method was employed to synthesize SiC fibers via microwave heating by uniformly combining the raw materials with Cu and Ni catalysts. The thermal effects and growth mechanisms of SiC were investigated using COMSOL Multiphysics software and DFT calculations for samples with Cu and Ni catalysts, respectively. The occurrence of magnetic losses played a significant role at low temperatures in the samples with Ni catalyst, resulting in the formation of local hotspots and the formation of molten Ni–Si alloys.Whereas, a reflection effect was observed in the samples with Cu catalyst, resulting in a more uniform temperature distribution. The V-L-S growth mechanism was identified in the SiC fibers synthesized with Ni catalyst during microwave heating, while the V–S growth mechanism was observed in the SiC particles synthesized with Cu catalyst. [ABSTRACT FROM AUTHOR]