脉冲放电制备链枝状非晶态Ni-P合金粉体的晶化行为

在镍盐溶液中利用脉冲放电技术制备出Ni-P合金粉体,并用场发射扫描电镜(FESEM)、透射电镜(TEM)、X射线衍射(XRD)及差热分析(DTA)等手段研究非晶粉体的晶化行为和组织结构特征.结果表明:Ni-P合金粉体形貌为链枝状,径向可达500nm左右,长度可达数微米.制备的合金粉体为非晶态结构,在280℃以下热处理时没有改变非晶态结构:在300℃开始晶化,析出亚稳相Ni₅P₂和Ni₁₂P₅;在320℃开始析出稳定相Ni和Ni₃P;温度升高到400℃时,亚稳相消失.采用Kissinger公式计算出该合金粉体的晶化激活能为291.76kJ·mol^-1.

Crystallization behavior of amorphous Ni-P chain dendritic alloy particles prepared by pulse discharge

Ni-P alloy particles were synthesized by means of pulse discharge in nickel salt solution.The microstructure characterization and crystallization behavior of the particles were investigated using field emission scanning electron microscopy (FESEM),transmission electron microscopy (TEM),X-ray diffraction analysis (XRD) and differential thermal analysis (DTA).The results show that the particles exhibit the morphology of a dendrite-like and chain-like combination,with the diameter of up to about 500 nm and the length of several microns.Their structure is amorphous and maintains at temperatures lower than 280 ℃,but begins to crystallize into metastable phases Ni₅P₂ and Ni₁₂P₅ at 300 ℃.Ni and Ni₃P stable phases appear at 320 ℃,and the metastable phases disappear above 400 ℃.The crystallization activation energy is 291.76 kJ·mol^-1 determined by the Kissinger equation.