机械球磨法添加Fe、Co及Al制备镁基储氢材料

Synthesis of Mg-based hydrogen storage material by mechanical ball milling with addition of Fe,Co and Al

采用等通道转角挤压(ECAP)方式细化ZK60合金晶粒,再利用机械球磨法分别添加Fe、Co及Al制备了3种储氢材料。采用X射线衍射仪、储氢特性测试仪和扫描电镜研究了储氢材料的高周期吸/放氢性能及其显微组织变化。结果表明:ZK60-Fe、ZK60-Co和ZK60-Al的吸氢速率均随着吸/放氢循环次数增加而增大,其中ZK60-Al的吸氢速率增大最快,第200次吸/放氢循环的5min内吸氢量接近60min内总的吸氢量;随着吸/放氢循环次数增加,储氢材料中会生成MgH2而导致储氢量递减,其中ZK60-Fe吸氢量递减速率减缓最快,仅吸/放氢循环了50次就开始减缓;这3种储氢材料经多次吸/放氢循环后均会出现微粉化,微粉化增多和吸氢量减少主要发生在循环吸/放氢初期。

The equal channel angular pressing(ECAP)was used to refining grain size of ZK60 alloy.Three kinds of Mg-based hydrogen storage materials were prepared by mechanical ball milling with addition of Fe,Co and Al.High cycling hydriding/dehydriding performance and microstructural evolution before and after cycling hydriding/dehydriding were studied by hydrogen storage characteristic tester,XRD diffractometer and SEM.The study showed that the hydrogen absorption rate of ZK60-Fe,ZK60-Co and ZK60-Al increased with the increase of the numbers of hydriding/dehydriding cycles,and the increase of hydrogen absorption rate of ZK60-Al was the fastest.The amount of hydrogen absorbed in the 5min during the 200th hydriding/dehydriding cycle was close to the total hydrogen uptake in 60min.With the increase of the number of hydriding/dehydriding cycles,the hydrogen storage decreased with the formation of MgH2 in the hydrogen storage material,and the decrease of ZK60-Fe hydrogen absorption decreased most rapidly,which begins to slow down after 50 cycles.The three kinds of hydrogen storage materials will be micronized after repeated hydriding/dehydriding cycles.Micronization and hydrogen absorption decreased mainly in the initial stage of circulating absorption/hydrogen release and later stable.The increase of micronization and the decrease of hydrogen uptake mainly occurred during the initial stage of cyclic hydriding/dehydriding.