Fe-TiC复合纳米粉体的制备和氧化特性

Preparation and oxidation resistance of Fe-TiC composite nanopowders

用电弧放电法在H2+CH4+Ar的混合气氛中蒸发Fe-Ti合金制备了Fe-TiC复合纳米粉体。用XRD、TEM、DSC-TG、化学分析和氧含量分析等手段对样品进行了分析。结果表明,粉体由Fe、TiC和少量Fe3C组成,复合粒子的形态主要有哑铃形和多面体形,复合粒子的生成机制遵寻VLS机制。在室温大气条件下,粉体中TiC相的含量越高则抗氧化性越好。在流动空气中,温度高于330℃时样品氧化明显加快,在410℃左右,TiC纳米粒子氧化分解。

Fe-TiC composite nanopowders were prepared by arc discharge evaporating Fe-Ti alloys in H2＋CH4＋Ar atmosphere.The structure,morphology,growth mechanism and oxidation resistance of the composite nanoparticles were studied using X-ray diffraction（XRD）,transmission electron microscopy （TEM）,differential thermal and thermogravimetric analysis（DSC-TG）,chemical analysis and gas analysis.The results show that the composite nanopowders consists of three phase of Fe,TiC and Fe3C.The morphology of composite nanoparticles are two types,one is dumbell-like,another is polyhedron.The growth mechnanism of composite nanoparticles is VLS.Resistance oxidation of composite nanopowders enhance with mass fraction of TiC increasing at room temperature.Velocity of oxidation of composite nanopowders are evidently accelerated over 330℃ and the TiC nanoparticles are oxidized to dissolve at about 410℃ in flow air.