SiC fibers with different diameters exhibiting excellent high-temperature resistance and oxidation resistance

SiC fibers have important application in aerospace and other high-tech equipment due to their excellent mechanical properties and thermal resistance. In this work, SiC fibers with diameters of 9, 14, 60 μm were prepared in order to investigate the influence of different diameters on the precursor-derived SiC fibers. The results showed that the polycrystalline structure and near stoichiometric composition of the SiC-9 and SiC-14 fibers were achieved by the “one-step” approach. However, the sintering for SiC-60 fiber was insufficient due to the largest diameter. Moreover, the tensile strength of SiC fibers decreased from 1.88 GPa to only 0.28 GPa with increment of the fiber diameter. The fibers exhibited excellent high temperature resistance with tensile strength retention reaching over 94% after being kept at 1900 °C in argon for 1 h. Furthermore, the SiC fibers with sintered and densified microstructure showed good oxidation resistance. This work could help to further optimize the structure of the polycrystalline near stoichiometric SiC fibers for higher mechanical and thermal performance.