(浙江大學 材料科學與工程系， 杭州 310027)
摘 要: 納米晶Mg2Ni1-xCrx (x=0,0.1,0.2,0.3)合金由純Mg、Ni、Cr粉在500℃經(jīng)3h燒結(jié)后機械球磨而成。在210℃吸氫、250℃放氫的條件下，添加Cr后合金的最大吸放氫量明顯提高; 納米Mg2Ni0.8Cr0.2合金的氣態(tài)儲氫量和吸氫動力學性能較好，第一次放氫量就達到3.0 %，并且循環(huán)穩(wěn)定性良好，吸氫后生成Mg2NiH4、Mg2NiH0.24相。納米Mg2Ni0.7Cr0.3合金的放氫量在不經(jīng)過活化的條件下便達到最大值，然而循環(huán)穩(wěn)定性差, 這是由于循環(huán)過程中有MgH2生成而造成的。
關(guān)鍵字: 燒結(jié);機械球磨;儲氫;Mg2Ni合金;納米晶
Cr additions
GAO Rong-gang, CHEN Chang-pin
（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
