Preparation and high‐temperature behavior of HfC–SiC nanocomposites derived from a non‐oxygen single‐source‐precursor |
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Authors: | Jun Cheng Xiaozhou Wang Hao Wang Changwei Shao Jun Wang |
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Affiliation: | Science and Technology on Advanced Ceramic Fibres and Composites Laboratory, National University of Defense Technology, Changsha, Hunan, China |
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Abstract: | A single‐source precursor for the preparation of HfC‐SiC ceramics was synthesized via a Grignard reaction using bis(cyclopentadienyl)hafnium(IV) dichloride, trans‐1,4‐dibromo‐2‐butene, and (chloromethyl)trimethylsilane as raw materials. The composition, structure, pyrolysis process and high‐temperature behavior of the precursor were investigated. The results show that the precursor with a backbone comprising Hf–C, Si–C and CH=CH groups exhibits good solubility in common solvents, such as tetrahydrofuran, dimethylbenzene, and chloroform. Pyrolysis of the precursor at 1000°C yielded a microcrystalline HfC phase with a ceramic yield of 63.86 wt%. The pyrolytic products at 1600°C were HfC–SiC nanocomposite ceramics, which exhibited good thermal stability up to 2400°C. The formation of a (Hf,Si)C solid‐solution would be beneficial for densification during the sintering process. The non‐oxygen structure, high ceramic yield, homogeneous composition and excellent high‐temperature behavior of the pyrolytic products make the as‐prepared precursor a promising material for the preparation of high‐performance ultra‐high‐temperature ceramics. |
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Keywords: | HfC‐SiC high‐temperature behavior precursor pyrolysis ultra‐high‐temperature ceramics |
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