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以煤沥青甲苯可溶组分、聚碳硅烷和吡啶硼烷为原料合成了B-Si掺杂沥青,B-Si掺杂沥青经炭化处理得到了B-Si掺杂炭材料。研究结果表明,炭化温度对B-Si掺杂炭材料的物相组成、微观结构和抗氧化性能有重要影响。1200℃炭化处理得到的B-Si掺杂炭材料中含有无定形B4C和Si C微晶,在空气气氛中容易快速氧化形成B2O3和Si O2,Si O2可以进一步在B2O3中溶解形成固溶体,从而提高炭材料表面形成的氧化膜的热稳定性。与在800℃、1000℃、1400℃和1600℃炭化得到的B-Si掺杂炭材料相比,在相同氧化条件下,1200℃炭化得到的B-Si掺杂炭材料显示了较好的抗氧化性能,它在1000℃空气气氛中氧化1 h,失重率仅为5.7 wt%,比其它B-Si掺杂炭材料的失重率小很多。
B-Si doped bitumen was synthesized from toluene soluble fraction of coal tar pitch, polycarbosilane and pyridine borane, and B-Si doped carbon was obtained by carbonization treatment of B-Si doped bitumen. The results show that the carbonization temperature has an important effect on the phase composition, microstructure and oxidation resistance of B-Si-doped carbon materials. The B-Si-doped carbon obtained by carbonization at 1200 ℃ contains amorphous B4C and SiC crystallites and easily oxidizes to form B2O3 and Si O2 in air atmosphere. Si O2 can be further dissolved in B2O3 to form solid solution, thereby increasing Thermal stability of oxide film formed on the surface of carbon material. The B-Si-doped carbon materials obtained by carbonization at 1200 ℃ under the same oxidation conditions showed better resistance than the B-Si-doped carbon materials obtained by carbonization at 800 ℃, 1000 ℃, 1400 ℃ and 1600 ℃ It is oxidized at 1000 ℃ for 1 h in air atmosphere, and its weight loss rate is only 5.7 wt%, which is much lower than that of other B-Si-doped carbon materials.