A new SiC fiber was prepared by the pyrolysis of polycarbosilane (PCS) fiber cured with unsaturated hydrocarbons. The fiber with oxygen content of 4wt%-6wt%, has high tensile strength of 2.5-2.8GPa. The specific resistance of the fiber is only about 0.5¦¸¡¤cm, which is much lower than general SiC fiber obtained from traditional air curing process. Results show that the fiber has an excess carbon layer with a thickness of about 50nm in the circular outer part, and the layer changes little after thermal exposure in argon. Compared with the ceramic grade fiber Nicalon NL202, thermal resistance to degradation of the fiber¡¯s mechanical property is improved by 200-300¡䬠The low specific resistance of the fiber also exhibits excellent thermal stability, which almost remains at 0.4-0.8¦¸¡¤cm after thermal exposure test from the room temperature to 1600¡䟩n argon.

Polymer-derived method is the main preparation method for continuous SiC fiber. So far, three generations of SiC-based fibers have been developed. SiC fiber is mainly used as reinforcement for SiC matrix to prepare SiC f /SiC composite, which exhibits excellent properties such as high-temperature resistance, oxidation resistance, high-temperature creep resistance, and neutron radiation stability. Therefore, it is considered as a promising preferred alternative material for structural components which works under harsh environments. In this review, the domestic and oversea development of the polymer-derived SiC fibers are introduced, in particular the different approaches for preparation and the characteristics of the 3 rd generation fibers. Then, the development of SiC f /SiC preparation technology and properties are reviewed and the relationship between the innovation in fabrication of SiC f /SiC composite and the development of SiC fiber is hightlighted. Finally, the application progress of SiC f /SiC composite in high performance aero-engines and fusion power cores is summerized. Meanwhile, some perspectives on the development of domestic SiC fibers and SiC f /SiC are also discussed.

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