Co掺杂对Nb_(95)W_(5)二元固溶体合金结构和氢渗透性能的影响  

Effects of Co dopping on structure and hydrogen-permeation properties of Nb_(95)W_(5) solid solutions

作　　者：韦甜甜 吴晨曦 张艳丽[1] 王仲民[1] 葛宇 王凤[1] 姚青荣[1] 邓健秋[1] 周怀营[1] WEI Tiantian;WU Chenxi;ZHANG Yanli;WANG Zhongmin;GE Yu;WANG Feng;YAO Qingrong;DENG Jianqiu;ZHOU Huaiying(School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China)

机构地区：[1]桂林电子科技大学材料科学与工程学院,广西桂林541004

出　　处：《功能材料》2021年第2期2141-2146,共6页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51961010,51901054);大学生创新创业训练资助项目(201810595195,201910595301)。

摘　　要：合金化是克服第五副族金属(Nb,V,Ta)氢脆问题的有效方法。以Nb-5W为基础成分,探索第三组元(Co)掺杂(X=1,2,3,5)对Nb_(95-x)W_(5)Co_(x)合金结构和氢渗透性能的影响规律。研究证实:制备的Nb_(95-x)-W_(5)Co_(x)样品为Nb-bcc固溶体合金,随着Co掺杂量增加,其晶胞畸变收缩明显,形成贫Co基体区和以NbCo化合物为基的富Co晶界偏析区。Co掺杂降低基础合金的氢溶解度、增大氢化物形成焓,有利于氢的扩散,有助于改善合金膜的氢渗透性能。Nb_(90)W_(5)Co_(5)合金有高的氢化物形成焓(-22.3 kJ/mol)、高的氢扩散系数(1.57×10^(-9) cm^(2)/s)、最大的承受载荷(78.4 N)和位移量(0.9 mm)。Co掺杂引起的晶格畸变和富Co晶界偏析起到了固溶强化和改善合金抗氢脆性能的作用。Alloying is an effective method to solve hydrogen embrittlement ofⅤB metals(Nb,V,Ta).Effect of Co dopping on structure and hydrogen-permeation properties of Nb95-xW5Cox(x=1,2,3,5)have been investigated in this work.The results indicate that as-melted Nb95-xW5Cox samples are all solo Nb-bcc solid solutions.The degree of lattice shrinking-distortion of these samples is affected by dopping amount of Co.Co-rich NbCo soluton structure is precipitated at grain boundaries and intracrystalline defects of Nb solid solution based on the matrix(Co-poor region).Co-dopping resultes in the decrease of hydrogen solution and the increase of hydride formation enthalpy,which benefit H-diffusion and the improvement of hydrogen-permeation properties of Nb_(95-x)W_(5)Co_(x) alloys.Nb_(90)W_(5)Co_(5) alloy has lower absolute value of hydride formation ehthalpy(-22.3 kJ/mol),higher hydrogen-diffusion coefficient(1.57×10^(-9)cm^(2)/s),the maximum values of critical load(78.4 N)and larger displacement amount(0.9 mm).The improvement of hydrogen embrittlement resistance of Nb_(95-x)W_(5)Co_(x) samples can be attributed to solution strengthening caused by Co-dopping.

关 键 词：Nb_(95)W_(5)合金 CO掺杂 形成焓 氢扩散系数 抗氢脆 

分 类 号：TB31[一般工业技术—材料科学与工程] TK91[动力工程及工程热物理]