(浙江大学 材料科学与工程系， 杭州 310027)
摘 要: 纳米晶Mg2Ni1-xCrx (x=0,0.1,0.2,0.3)合金由纯Mg、Ni、Cr粉在500℃经3h烧结后机械球磨而成。在210℃吸氢、250℃放氢的条件下，添加Cr后合金的最大吸放氢量明显提高; 纳米Mg2Ni0.8Cr0.2合金的气态储氢量和吸氢动力学性能较好，第一次放氢量就达到3.0 %，并且循环稳定性良好，吸氢后生成Mg2NiH4、Mg2NiH0.24相。纳米Mg2Ni0.7Cr0.3合金的放氢量在不经过活化的条件下便达到最大值，然而循环稳定性差, 这是由于循环过程中有MgH2生成而造成的。
关键字: 烧结;机械球磨;储氢;Mg2Ni合金;纳米晶
Cr additions
（Department of Materials Science and Engineering,
Zhejiang University, Hangzhou 310027, China）
Abstract:Nanocrystalline Mg2Ni1-xCrx (x=0,0.1,0.2,0.3) alloys were prepared by sintering with a mixture of Mg, Ni and Cr powder at 550℃ for 3h and subsequent high energy mechanical milling for 30h. Under hydriding at 210℃ and dehydriding at 250℃, addition of Cr to Mg2Ni alloy improves the hydrogen capacity. The nanocrystalline Mg2Ni0.8Cr0.2 alloy exhibits the better hydrogen storage properties and hydriding / dehydriding kinetics, with the first maximum desorption hydrogen content reaching to 3.0% and with the good cyclic stability. Mg2NiH4 and Mg2NiH0.24 phases form during hydrogen absorption. The nanocrystalline Mg2Ni0.7Cr0.3 could obtain the maximum hydrogen desorption without any activation but its cyclic stability is reduced due to MgH2 phase formed during hydriding-dehydriding cycles.
Key words: sintering; mechanical milling; hydrogen storage; Mg2Ni alloy; nanocrystalline
