Enhanced antioxidation performance of hafnium-doped SiOC ceramic fibers for high-temperature environment applications

With the rapid advancement of aerospace and chemical industries, there was an increasing demand for high-performance structural materials that could withstand extreme high-temperature environments. Ceramic fibers and their composites were investigated as promising candidates due to their low density, high specific strength and modulus, excellent oxidation resistance, and ablation performance, which made them ideal for structural-functional integration under harsh thermal conditions. This study explored the preparation of Hafnium-doped silicon oxycarbide (SiOC) ceramic fibers via emulsion electrospinning, focusing on the influence of key parameters such as water-to-oil (W/O) ratio, spinning voltage, and propulsion speed on fiber morphology and structure. The emulsion method successfully addressed the bottleneck in the fabrication of sub-micron ceramic fibers. The results demonstrated the W/O ratio significantly affects fiber morphology, with lower ratios reducing bead formation and producing more uniform fibers. The optimal spinning voltage was found to be between 12.0 and 15.0 kV, yielding fibers with an average diameter of approximately 320 nm. The fibers exhibited excellent thermal stability, with a weight loss of only 2.38 % after pyrolysis at 800 °C in a nitrogen atmosphere. X-ray diffraction (XRD) analysis confirmed the presence of SiO 2 , SiC, HfO 2 , and HfSiO 4 phases, indicating successful hafnium doping. This study highlighted the potential of emulsion electrospinning as a scalable and environmentally friendly method for producing high-performance ceramic fibers with submicron scale, demonstrating its effectiveness in fabricating ultrathin fibers suitable for high-temperature applications.