【摘要】 采用真空电弧熔炼法制备了Zr_1-xNb_xCo （x=0,0.05,0.1,0.15,0.2）合金,研究了Nb掺杂对ZrCo合金相组成、吸放氢及抗歧化性能的影响。XRD结果表明:Zr_1-xNbxCo （x=0～0.2）合金主相为ZrCo相,含有少量ZrCo₂杂相;氢化物为ZrCoH₃相。Nb掺杂有利于ZrCo合金吸放氢性能的提高:ZrCo吸氢反应活化时间为7690 s,Zr_0.8Nb_0.2Co缩短至380s;ZrCo吸氢反应表观活化能力44.88 kJ·mol^-1 H₂,Zr_0.8Nb_0.2Co降低至32.73 kJ·mol^-1 H₂;10 K/min升温速度下,ZrCo-H系统放氢温度为597.15 K,Zr_0.8Nb_0.2Co-H系统降低至541.36 K;ZrCo-H系统放氢反应表观活化能为100.55 kJ·mol^-1 H₂,Zr_0.8Nb_0.2Co-H系统降低至84.58 kJ·mol^-1 H₂。放氢模式下798 K保温10 h ZrCo歧化83.68%,Zr_0.8Nb_0.2Co仅歧化8.71%;Nb掺杂降低合金氢化物8e间隙氢原子数量,减小岐化反应驱动力,提高合金抗歧化性能。更多还原

【Abstract】 Zr_1-xNb_xCo（x=0,0.05,0.1,0.15,0.2） alloys were prepared via vacuum arc-melting method.The effects of substituting Zr with Nb on the phases,hydrogen absorption-desorption properties and anti-disproportionation performance of the mentioned alloys were systematically investigated.The XRD results show that Zr_1-xNb_xCo（x=0-0.2） alloys exhibit ZrCo and ZrCo₂ phases and their corresponding hydrides mainly consist of ZrCoH₃ phase.Substitution of Nb for Zr is beneficial to the hydrogen absorption and desorption properties.The activation time decreases significantly from 7690 s for ZrCo to 380 s for Zr_0.8Nb_0.2Co and the activation energy for hydrogenation decreases from 44.88 kJ·mol^-1 H₂ for ZrCo to 32.73 kJ·mol^-1 H₂ for Zr_0.8Nb_0.2Co.The desorption temperature at heating rate of 10 K/min decreases from 597.15 K for ZrCo-H system to 541.36 K for Zr_0.8Nb_0.2Co-H system,and the activation energy for dehydrogenation decreases from 100.55 kJ·mol^-1 H₂ for ZrCo-H system to 84.58 kJ·mol^-1 H₂ for Zr_0.8Nb_0.2Co-H system.Additionally,the extent of disproportionation after disproportionating at 798 K for 10 h decreases from 83.68% for ZrCo-H system to 8.71% for Zr_0.8Nb_0.2Co-H system.The positive effect of Nb substitution for improving the anti-disproportionation property of ZrCo alloys is attributed to the reduction of hydrogen atoms in 8 e sites,which decreases the driving force of the disproportionation reaction.更多还原