High energy consumption and complex processes constrain the industrial production of high-performance SiC/SiO2 fibers. A direct synthesis route for SiC/SiO2 fibers at low temperatures (700–1100 °C) is developed in this work using pure-material microwave heating without external heating assistance. The phase composition, microstructure, and microwave-assisted synthesis process of the fibers were systematically investigated. A two-stage growth mechanism is proposed based on real-time microwave coupling analysis, consisting of kinetically controlled SiC fiber growth followed by thermodynamically driven SiO2 bead formation. The SiC/SiO2 fibers synthesized at 1000 °C exhibit outstanding electromagnetic wave absorption performance, achieving a minimum reflection loss (RLmin) of −42.49 dB at an ultrathin thickness of 2.9 mm, demonstrating great potential for lightweight, high-efficiency microwave absorbers.
Dong et al. (Tue,) studied this question.