Influence of Carbon Nanotube Addition on Microstructure and Microwave Heating Performance of Polycarbosilane-Based Silicon Carbide

The microwave heating of silicon carbide is induced at a specific frequency of 2.45 GHz, leading to rapid heating within a temperature range of several hundred degrees Celsius. In this study, a mechanochemical curing process using iodine was employed to cure polycarbosilane (PCS), followed by the addition of carbon nanotubes (CNTs) to produce mixed polymer powders. The effects of the CNT addition on the microstructure, crystalline structure, and microwave heating properties were investigated. The findings indicated that the incorporation of CNTs generally led to a reduction in the number of micropores; however, when the CNT concentration exceeded 10 wt%, the aggregation of CNTs became evident. In terms of microwave heating properties, the sample containing 0.1 wt% CNTs achieved the highest temperature, whereas samples with a higher CNT content demonstrated a heating limit of approximately 500 °C. Remarkably, post-processing of the specimens with 10 wt% CNTs enabled rapid heating to approximately 1800 °C within 4 s of microwave exposure.