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采用溶液燃烧合成和氢气还原两步法制备具有超细Y2O3弥散相的Ni-Y2O3纳米复合粉末。通过DTA-TG分析探讨燃烧机理,使用场发射扫描电镜、透射电镜和X射线衍射分析技术表征燃烧得到的粉末形貌和Ni-Y2O3纳米复合粉末的形貌和物相。详细讨论原料中硝酸镍与尿素配比对燃烧得到的粉末形貌、物相和比表面积的影响。高分辨透射形貌分析结果显示合成得到的Ni-Y2O3纳米复合粉末中均匀分布的Y2O3弥散相的尺寸在10 nm左右,并且在放电等离子烧结致密化后并未明显长大。
The Ni-Y2O3 nano-composite powder with ultrafine Y2O3 dispersed phase was prepared by two-step solution combustion synthesis and hydrogen reduction. The combustion mechanism was discussed by DTA-TG analysis. The morphology of the powder and the morphology and phases of the Ni-Y2O3 nanocomposite powders were characterized by field emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction analysis. The effect of the ratio of nickel nitrate and urea in the raw materials on the morphology, phase and specific surface area of the powder obtained by combustion was discussed in detail. High-resolution transmission morphology analysis results show that the size of the Y2O3 dispersed phase uniformly distributed in the synthesized Ni-Y2O3 nano-composite powder is about 10 nm, and does not obviously grow after the densification by spark plasma sintering.