关键词: 液相先驱体转化法;溶胶凝胶法;ZrC;SiC;纳米粉体

Abstract: ZrC-SiC nano-composite powders were synthesized via liquid precursor conversion and sol-gel method,using zirconium oxychloride octahydrate as zirconium source, tetraethoxysilance as silica source and sucrose as carbon source.Functional groups of zirconium-containing polymer precursor were analyzed by fourier transform infrared spectrometer.Effects of Si/Zr molar radio on phase composition and microstructure of samples were investigated by X-ray diffractometer and scanning electronic microscopy, respectively.It is shown that the zirconium-containing polymer precursor has a chain-like or network-like structure.After sinterd at 1450℃for 2 h,there is still unreactive m-ZrO2phase in the sample whose Si/Zr molar radio is 0.28.When Si/Zr molar radio increases to 1.11,2.56,5.88 and 23.17,nearly pure ZrC-SiC nano-composite powders can be synthesized.The powder size changes little with the increasing of Si/Zr molar ratio.Composite powders with an average particle size of 90 nm and evenly elements distribution are obtained when Si/Zr molar ratio is 2.56.

Key words: liquid precursor conversion method;sol-gel method;ZrC;SiC;nano-powder