貯氫合金的循環(huán)穩(wěn)定性
趙小龍1， 王新林2
(1. 內(nèi)蒙古科技大學(xué) 材料學(xué)院， 包頭 0140101；
2. 鋼鐵研究總院 功能材料研究所， 北京 100081)
摘 要: 為了提高La-Mg-Ni系貯氫合金的循環(huán)穩(wěn)定性， 以Al部分替代Ni, 采鑄造及快淬工藝制備了La0.7Mg0.3Ni2.55-xCo0.45Alx(x=0, 0.1, 0.2, 0.3, 0.4)電極合金， 研究了Al替代量及快淬工藝對(duì)合金微觀結(jié)構(gòu)及電化學(xué)循環(huán)穩(wěn)定性的影響。 X射線衍射分析結(jié)果表明： 鑄態(tài)及快淬態(tài)合金具有多相結(jié)構(gòu)， 包括(La, Mg)Ni3相、 LaNi5相和一定量的LaNi2相； Al替代使鑄態(tài)合金中LaNi2相的量顯著增加， 但對(duì)快淬態(tài)合金中LaNi2相的相豐度影響不顯著。 電化學(xué)測(cè)試結(jié)果表明： 隨Al替代量的增加，合金的循環(huán)壽命大幅度提高； 快淬處理可以提高合金的循環(huán)壽命， 但隨Al替代量的增加， 淬速對(duì)循環(huán)壽命的影響減小。
關(guān)鍵字: La-Mg-Ni系貯氫合金； Al替代Ni； 微觀結(jié)構(gòu)； 循環(huán)穩(wěn)定性
(x=0-0.4) hydrogen storage alloys
DOND Xiao-ping1, ZHAO Xiao-long1, WANG Xin-lin2
（1. School of Material, Inner Mongolia University of Science and Technology,
Baotou 014010, China;
2. Department of Functional Material Research,
Central Iron and Steel Research Institute, Beijing 100081, China）
Abstract: In order to improve the cycle stability of La-Mg-Ni system (PuNi3-type) hydrogen storage alloy, Ni in the alloy was partly substituted by Al, and La0.7Mg0.3Ni2.55-xCo0.45Alx(x=0, 0.1, 0.2, 0.3, 0.4) hydrogen storage alloys were prepared by casting and rapid quenching. The effects of substituting Ni with Al and rapid quenching on the microstructures and cycle stability of the alloys were investigated. The results obtained by XRD show that the as-cast and quenched alloys have a multiphase structure, including the (La, Mg)Ni3 phase, LaNi5 phase and LaNi2 phase. The substitution of Al for Ni increases the amount of LaNi2 phase in the as-cast alloys, but it has an inappreciable influence on the abundance of the LaNi2 phase in the as-quenched alloy. The results obtained by the electrochemical measurement indicate that the cycle stability of the as-cast and quenched alloys significantly increases with the increase of Al content. Rapid quenching can improve the cycle stability of the alloys, but the influence of the quenching rate on the cycle stability of the alloy gradually decreases with the increase of the Al content.
Key words: La-Mg-Ni system hydrogen storage alloy; substituting Ni with Al; microstructures; cycling stability
