摘要
为了考察Mo部分替代Ti对高容量V40Ti50Fe10合金储氢性能的影响,采用电弧熔炼制备了V40Ti50-xMoxFe10(x=0~30)合金,系统地研究了该系列合金的结构和储氢性能随Mo替代Ti含量的变化规律,并探讨合金储氢容量的衰退机制。研究表明:该系列合金均由主相体心立方(BCC)固溶体和少量的C14型Laves第2相组成;Mo取代Ti并未改变合金的主相结构,但Laves第2相的含量明显降低,合金整体均匀性增加;随着Mo含量的增加,BCC相的晶胞体积逐渐减小,合金的放氢量总体呈现下降趋势但中间出现波动状态,而放氢平台压则持续上升;在这一系列合金中,V40Ti40Mo10Fe10合金的储氢性能较优,具有相对宽泛且平坦的放氢压力平台,可逆储氢量较高,且室温下吸放氢过程均可在5 min内完成。循环测试表明,合金氢化物在吸放氢过程中会形成难以活化的TiFe相,导致合金出现成分分离,影响合金的稳定性,从而造成储氢容量衰退。
To investigate the effects of partial substitution of Mo for Ti on the hydrogen storage property of V40Ti50Fe10 alloy, V40Ti50-xMoxFe10(x=0-30) alloys were prepared by arc melting, and the evolutions of their microstructures and hydrogen storage property were analyzed. Results show that these alloys are composed of main phase BCC solid solution and a small amount of secondary C14 Laves phase. With the increasing of Mo content, the amount of C14 Laves phase obviously decreases, the homogeneity of the alloys increases, and the unit cell volume of BCC phase gradually decreases. Meanwhile the dehydrogenation capacity generally shows a downward trend with several fluctuations, and the dehydrogenation plateau pressure continues to rise. Among these alloys, V40Ti40Mo10Fe10 shows excellent hydrogen storage property with a relatively broad and flat dehydrogenation plateau, high reversible hydrogen storage capacity, and excellent hydrogen absorption and desorption kinetics. Cycling measurements indicate that a new TiFe phase is formed during the dehydrogenation process, which results in the composition segregation of these alloys, thus influencing their stability and reducing their hydrogen storage capacity.
作者
曹志杰
马晓波
CAO Zhijie;MA Xiaobo(School of Physics and Electronic-Electrical Engineering,Ningxia University,Yinchuan 750021,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2019年第9期137-144,共8页
Journal of Xi'an Jiaotong University
基金
宁夏大学自然科学研究基金资助项目(ZR1713)
国家自然科学基金青年科学基金资助项目(51801107)
关键词
钒基固溶体合金
储氢性能
放氢平台压
V-based solid solution alloys
hydrogen storage property
dehydrogenation plateau pressure
