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Preparation of SiC preceramic process in order to improve the resistance of the SiC ceramic ultra-high temperature and oxidation resistance, the introduction of heterogeneous elements, and the synthesis of novel SiC preceramic has become the mainstream of today's high performance SiC ceramics development. This paper LPCS raw materials, synthesis containing zirconium, tantalum, hafnium SiC ceramic the pioneer body PZCS (Polyzirconoca-rbosilane) the PTCS (Polytantalocarbosilane) and the PHCS (Polyhafnocarbosilane), and preparation of the Si-Zr-CO fiber, Si-Ta -CO fibers and Si-Hf-CO fiber. Pioneer in body composition structure, reaction influencing factors and reaction mechanism, and to study the composition of the fiber structure and resistance to ultra-high temperature and antioxidant properties. To LPCS and Zr (AcAc) 4 was synthesized containing zirconium SiC preceramic PZCS. When Zr (AcAc) 4 dosage 4 wt% ~~ 8 wt% pyrolysis temperature of 480 ~ 520 ℃, reaction temperature of 390 ~~ 450 ° C, reaction time 6 ~ 8h synthetic PZCS precursor The yield was 41% to 63%, a melting point of 160 to 270 ° C, with a good spinnability. PZCS ceramic yield of 70% to 82.4% for the high ceramic yield of Precursor. Si-Zr-CO fibers, obtained by PZCS system chemical formula SiC this 1.24 the H x O 0.56 Zr 0.0129 , fiber diameter 11μm, tensile strength of 2.5GPa. High-temperature resistant properties of the fiber are good in 1450 ℃ and 1600 ° C treatment, the strength retention rate was 72% and 36%, respectively, 1800 ° C treatment after the chemical formula of Si-Zr-CO fibers SiC 0.99 H x O 0.1 Zr y ; fiber anti-oxidant properties, heat treatment at 1000 ℃ air strength retention rate of 71.2% after 20h heat treatment 100h, the strength retention was 50%. To the LPCS and Ta (AcAc) (OEt) 4 was synthesized containing tantalum SiC preceramic PTCS When Ta (AcAc) (OEt) to 4 dosage 4 wt% ~~ the 10 wt%, the reaction temperature to 450 ° C, the reaction time was 6 ~ 12h, pyrolysis temperature of 500 ° C, synthetic PTCS Precursor for a yield of 66% to 73%, a softening point between 180 to 260 ° C, and the spinnability is good, higher than the same reaction under the conditions of the yield of the PCS precursor. The PTCS ceramic yield of 73.3% to 84.2%, for a high ceramic yield pioneer. Si-Ta-CO fibers, chemical formula obtained by PTCS system SiC 0.63 H x O 0.55 Ta y . Fiber diameter of 20 μm, the tensile strength of 1.9GPa. The fiber resistance to ultra-high-temperature performance 1450 ° C and 1600 ° C treatment, the fiber strength retention rate of 47% and 32%, respectively, Si-Ta-CO fiber chemical formula SiC after 1800 ° C treatment 1.19 H x O 0.056 Ta y ; fiber antioxidant properties, heat treatment at 1000 ℃ in air for 20h, strength retention rate of 57%, treatment 100h, the strength retention rate was 61%. To the LPCS and Hf (AcAc) 4 synthesized containing hafnium SiC preceramic PHCS. When Hf (AcAc) 4 of dosage 2 wt% ~~ 15 wt%, reaction temperature 450 ℃, reaction time 13 ~ 17h, pyrolysis temperature of 500 ℃, synthetic PHCS pioneer yield of 64% to 67%, the softening point of 160 ~ 300 ℃, good spinnability. The PHCS ceramic yield in the 67.0% to 83.9%, for a high ceramic yield pioneer. Si-Hf-CO by PHCS system was fiber formula for SiC 1.48 H x O . 1.17 Hf , y . The average fiber diameter of 14μm, an average tensile strength of 1.8 GPa. Good resistance to ultra-high-temperature performance of the fiber, 1450 ° C and 1600 ° C, after treatment, the strength retention rate was 61% and 39%, respectively, the chemical formula for the 1800 ° C after treatment of Si-Hf-CO fiber SiC 1.13 H x O 0.06 the Hf y; performance of Si-Hf-CO fiber antioxidant 1000 ℃ for 20h, strength retention rate of 74% . The air after the heat treatment at 1000 ℃ 100h, the strength retention rate was 46%. The introduction of heterogeneous elements significantly improved ceramic yield precursor and the overall performance of the SiC fibers, the resistance of Si-MCO fiber ultra-high temperature and antioxidant properties are superior to the Si-CO fiber. In contrast to the properties of the fibers of the Si-MCO seen the comprehensive performance of the Si-Zr-CO fibers superior to fibers of the Si-Ta-CO fiber and Si-Hf-CO.
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