配位共沉淀-直接还原法制备超细纤维状铁镍合金粉(英文)

采用配位共沉淀制备了铁镍合金前驱体,用氢气直接还原前驱体得到了超细纤维状铁镍合金粉。系统研究了反应物浓度、pH值、反应温度及添加剂等参数对前驱体制备过程的影响。分别采用XRD、TG-DTA和SEM对前驱体的结构、热分解过程和形貌进行了表征。结果表明,采用质量分数2%的PVP作为添加剂,当Fe2+和Ni2+(1:1)总浓度为0.8mol/L,pH值为6.2,反应温度为60°C时,可以制得分散良好、形貌均匀的纤维状前驱体。前驱体在420°C的氮气和氢气混合气氛下直接还原可以得到纯度高、分散性好的纤维状铁镍合金粉。

Preparation of ultra-fine fibrous Fe-Ni alloy powder by coordinated co-precipitation-direct reduction process

The precursor prepared by coordinated co-precipitation was direct reduced by hydrogen to ultra-fine fibrous Fe-Ni alloy powder. The effects of concentrations of reactants, pH value, reaction temperature and additive on the preparation of precursor were systematically investigated. The structures, thermal decomposition processes and morphologies of the precursors were characterized by X-ray diffraction (XRD), thermal gravity-differential thermal analysis (TG-DTA) and scanning electron microscoy (SEM). The results show that using 2% polyvinylpyrrolidone (PVP) (in mass fraction) as additive, a well-dispersed precursor with a uniform morphology can be obtained in a solution with Fe2+ and Ni2+ total concentration (1:1) of 0.8 mol/L, pH value of 6.2 at 60 °C, and a pure and well dispersed fibrous iron-nickel powder can be prepared by direct reduction of this precursor in a mixed atmosphere of nitrogen and hydrogen at the temperature of 420 °C.