Nb_(55−x)V_(x)Ti_(25)Co_(20)合金的显微组织和氢传输性能  

Microstructure and hydrogen transport properties of Nb_(55−x)V_(x)Ti_(25)Co_(20) alloys

作　　者：陈运灿 闫二虎 王金华 狄翀博 黄浩然 徐芬[1] 孙立贤[1] CHEN Yun-can;YAN Er-hu;WANG Jin-hua;DI Chong-bo;HUANG Hao-ran;XU Fen;SUN Li-xian(Guangxi Key Laboratory of Information Laboratory,Guilin University of Electronic Technology,Guilin 541004,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China;School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]桂林电子科技大学广西信息材料重点实验室,桂林541004 [2]中南大学粉末冶金研究院,长沙410083 [3]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《中国有色金属学报》2021年第5期1299-1309,共11页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51761009,51701048);广西自然科学基金资助项目(2020GXNSFAA159163);桂林电子科技大学研究生教育创新计划资助项目(2019YCXS109);广西信息材料重点实验室基金资助项目(191021-Z)

摘　　要：采用SEM和XRD等分析了Nb_(55−x)V_(x)Ti_(25)Co_(20)氢分离合金(x=0,…,25,%,摩尔分数)显微结构特征,研究其随V含量的变化规律;利用氢渗透性能测试仪和Devanathan-Stachurski型电解池测量上述合金的氢渗透和氢扩散性能,阐明合金成分、组织和性能参数之间的关系。结果表明:随V含量的逐渐增加,初生Nb相体积分数增加;相反地,两相共晶减少,当x>10(摩尔分数)时,由于大量(Nb,V,Ti)2Co相和微量V3Co相的析出,合金中由两相转变为四相组织;伴随上述过程,合金渗氢性能和抗氢脆性能先增加而后急剧降低,当x=10时,Nb45V10Ti25Co20在673 K具有最大的渗氢性能,即3.76×10^(−8) mol/(m·s·Pa1/2),是相同实验条件下Pd膜的2.4倍。另外,氢扩散系数随着x值的增加而增加,相反地,氢溶解度随之降低,由此证实前者是导致该系列合金氢渗透性能变化的主要原因。At present,group 5B metals (i.e.Nb,V and Ta) and their alloys have become one of the most promising hydrogen separation membrane materials to replace the traditional Pd membrane in the future.However,they are far from the standards proposed by the international department of energy.Hence,it is urgent to develop new hydrogen permeation membrane materials.With these considerations in mind,Nb_(55−x)V_(x)Ti_(25)Co_(20) hydrogen separation alloys (x=0,…,25,%) were investigated systematically.Firstly,the microstructure characteristics were analyzed by SEM and XRD,and their variation rule with V content was also obtained.After that,to clarify the relationships among alloy composition,microstructure and performance parameters,the hydrogen permeability and diffusion properties of these alloys were measured by hydrogen permeability tester and Devana than-Stachurski electrolytic cell.The results show that,with the gradual increase of V content,the volume fraction of primary Nb phase increases but the two-phase eutectic decreases in these alloys.When the V content is more than 10%(mole fraction),a large amount of (Nb,V,Ti)2Co phase and a small amount of V3Co phase precipitates in the alloys.As a results,it is transformed into a four-phase structure.With these changes,the hydrogen permeability and hydrogen embrittlement resistance increases first,and then decreases sharply.When x is 10,Nb45V10Ti25Co20 alloy exhibits the highest hydrogen permeability at 673 K,i.e.3.76×10-8 mol/(m·s·Pa1/2),which is 2.4 times than that of pure Pd.In addition,with the increase of x value (V content),the hydrogen diffusion coefficient (D) of the alloys increase whereas the hydrogen dissolution coefficient decrease (K),which demonstrates that the variation offfor these membranes is due to the change in D rather than K.

关 键 词：Nb_(55−x)V_(x)Ti_(25)Co_(20)氢分离合金 显微组织 氢渗透性能 

分 类 号：TG139[一般工业技术—材料科学与工程]