W掺杂的Nb基固溶体合金的结构和氢渗透性能  

Structure and Hydrogen-Permeation Properties of W-Doped Nb-Based Solid Solutions

作　　者：唐金亮 王仲民[1] 严晓锋 王凤[1] 姚青荣[1] 邓健秋[1] 周怀营[1] Tang Jinliang;Wang Zhongmin;Yan Xiaofeng;Wang Feng;Yao Qingrong;Deng Jianqiu;Zhou Huaiying(Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]桂林电子科技大学,广西桂林541004

出　　处：《稀有金属材料与工程》2020年第8期2807-2812,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51961010,51901054);广西自然科学基金(2016GXNSFGA38001);广西学位与研究生教育改革与发展专题(YCSW2018144)。

摘　　要：制备了W掺杂的Nb(100-x)Wx(x=2,5,8,10,16)合金,采用XRD、SEM、Sieverts气体吸附技术、电化学方法和三点弯曲试验研究了掺杂量对合金结构、氢化物形成焓、氢扩散系数和抗氢脆力学性能的影响。研究证实,熔炼制备Nb(100-x)Wx为Nb-bcc结构的固溶体合金,W掺杂引起晶体结构畸变收缩,其畸变行为随掺杂量增大更为明显。Nb基固溶体在匀晶转变时存在非平衡转变,形成富W和贫W区相间分散的枝状结晶形貌。随W掺杂量增大,其枝状结构趋于更加细化和致密、分界明显。W掺杂引起合金的氢化物形成焓增大、有利于H原子的释放,Nb84W16合金样品具有最大的氢扩散系数(1.66×10^-9cm·^2·s^-1),约是Nb98W2合金的1.8倍。W掺杂提高Nb(100-x)Wx固溶体合金的抗氢脆性能,Nb(84)W(16)合金膜有最大的临界载荷值(78.4 N)和最大位移量(0.83 mm),分别是Nb(98)W2合金膜的1.9倍和1.8倍,力学性能的改善与其枝状结晶结构有关。The phase structure,hydride formation enthalpy,hydrogen diffusion coefficient(DH)and mechanical properties of W-doped Nb100-xWx(x=2,5,8,10,16)alloys were investigated by XRD,SEM,PCT analysis,electrochemical method and three-point bending test.The results indicate that melting-prepared Nb100-xWx samples are Nb-based solid solutions with bcc structure.W-doping will induce the lattice distortion and shrink,and the distortion behavior is more obvious with the increase of W-doping content.Non-equilibrium transformation microstructure is observed in these Nb100-xWx samples,which presents dendritic morphology with W-poor region dispersed in W-rich matrix.Dense and refined dendritic morphology is observed obviously in Nb100-xWx(x=10,16)samples.W-doping results in the increase of the value of hydride-formation enthalpy,and benefits H-release of corresponding hydride.Higher H-diffusion coefficient(DH=1.66×10^-9 cm^2·s^-1)is obtained in Nb84W16 sample,which is about 1.8 times that of Nb98W2 sample.W-doping also improves the anti-hydrogen embrittlement capacity,and Nb84W16 sample has the largest critical load(78.4 N)and maximum displacement(0.83 mm),which is about 1.9 and 1.8 times that of Nb98W2 sample,respectively,indicating that the improvement of mechanical properties is related to its microstructure.

关 键 词：Nb固溶体 W掺杂 氢渗透 氢扩散系数 抗氢脆 

分 类 号：TG139.7[一般工业技术—材料科学与工程]