电弧等离子体法制备Mg-Ni储氢合金粉体

采用Mg粉、Ni粉混合,经球磨、烧结等不同工艺制备电弧阳极材料,通过直流电弧等离子体法制备了Mg-Ni储氢合金超细粉。用XRD、TEM、ICP分析手段研究了粉体的相组成、形貌、成分等。物相分析显示,Mg粉、Ni粉混合烧结后基本都转化为Mg2Ni相;经直流电弧等离子体后,Mg相增加,同时生成了MgNi2相,证明在电弧作用时母相Mg2Ni发生了分解生成Mg和Ni相,Mg与Ni再反应生成Mg2Ni和MgNi2。成分分析显示,烧结形成Mg2Ni后再经电弧作用更利于Ni的析出。TEM结果显示:Mg颗粒形貌近似六方形,颗粒大小为100~600nm;Mg2Ni颗粒附着在Mg大颗粒的表面,大小在10~50nm之间。纳米Mg2Ni颗粒附着在超细Mg粉上的这种结构将有助于改善Mg的吸放氢性能。

Preparation of Mg-Ni hydrogen storage alloy powders by direct-current arc plasma method

Mg-Ni based ultrafine powders were prepared through the direct-current （DC）arc plasma method using the arc anode material which was obtained by mixing,ball milling and sintering procedures from Mg and Ni powders.The phase components, morphology and composition of the powders were analyzed by the means of XRD,TEM and ICP.XRD analyses reveal the formation of Mg2 Ni after sintering the Mg and Ni powders.After arc plasma evaporation,Mg content increases and MgNi2 forms at the same time,indicating that Mg2 Ni decomposes into Mg and Ni during the arc evaporation and they react again to form Mg2 Ni and MgNi2 phases.ICP analysis shows that sintered Mg2 Ni can release more Ni during arc evaporation.TEM observation shows that those Mg particles have hexagonal shape with size ranging from 100 nm to 600 nm.While those Mg2 Ni nano grains,about 10-50 nm,attached on the Mg ultrafine particles.Such kind of microstructure will be helpful for improving the hydrogen sorption property of Mg.