氢含量对氢化锆相结构和残余应力的影响  

Phase Structure and Residual Stress of Zirconium Hydride with Different Hydrogen Contents

作　　者：白伟 王文科 王智辉 闫国庆 张建东[1,2,3] 王力军 Bai Wei;Wang Wenke;Wang Zhihui;Yan Guoqing;Zhhang Jiandong;Wang Lijun(National Engineerjing Laboratory of Biohydrometallury,China GRINM Co.,Ltd.,Beijing 101407,China;China GRINM Resources and Environment Tech.Co.,Ltd.,Beijing 100088,China;General Research Institute for Nonferrous Metals,Beijing 100088,China)

机构地区：[1]中国有研科技集团有限公司生物冶金国家工程实验室,北京101407 [2]有研资源环境技术研究院有限公司,北京101407 [3]北京有色金属研究总院,北京100088

出　　处：《稀有金属》2024年第1期138-144,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51674035)资助。

摘　　要：氢化锆是核反应堆理想的固体中子慢化剂,在制备过程中随着基体氢含量的增加,氢化物依次发生α→β→δ→ε的相转变,从而导致氢化锆基体中产生内应力,进一步导致氢化锆开裂。研究了氢化锆相组成、相结构和应力与氢含量的关系。采用X射线衍射(XRD)表征了样品的物相组成,H/Zr(原子比)为0.8时样品含α,γ,δ相,H/Zr为1.2和1.45时样品含γ和δ相,H/Zr为1.60和1.64时样品均只含δ相,H/Zr为1.85和1.90时样品均只含ε相,结果表明氢化锆中氢含量与物相组成的对应关系基本符合样品Zr-H相图。对XRD结果进行精修分析,得到δ相(面心立方(fcc))和ε相(面心四方(fct))氢化物晶格常数与氢含量的关系为:随着氢含量的增加,δ相氢化锆晶格常数a逐渐变大,晶胞体积也逐渐变大;氢含量越大,ε相氢化锆晶格常数a越大,c则越小,晶胞体积也更大。利用X射线衍射应力仪测量了样品表面残余应力,结果表明Zr-1Nb合金表面应力为压应力,大小为-163.7 MPa;氢化锆表面则为拉应力,结果表明:H/Zr为1.57时,表面应力是12.2 MPa;H/Zr为1.67时,表面应力是18.6 MPa;H/Zr为1.74时,表面应力是30.8 MPa;随着氢含量的增加,残余应力逐渐增大。Zirconium hydride is an ideal solid neutron moderator for nuclear reactors.During the preparation process,with the increase of hydrogen content in the matrix,the phase changes of α→β→δ→ε in turn occur in hydrides.This results in internal stress in zirconium hydride matrix and further leads to zirconium hydride crack.In this paper,zirconium hydride samples with different hydrogen content were prepared by gas phase hydride method.The relationship between phase composition,phase structure,stress and hydrogen content of zirconium hydride with different hydrogen content was studied.X-ray diffraction(XRD) was used to characterize the phase composition of the sample.When H/Zr was 0.8,zirconium hydride sample contained α,γ and δ phase hydrides;when H/Zr was 1.2 and 1.45,zirconium hydride samples contained γ and δ phase hydrides;when H/Zr was 1.60 and 1.64,zirconium hydride samples contained δ phase hydride;when H/Zr(atom fraction) was 1.85 and 1.90,zirconium hydride samples contained ε phase hydride.The results showed that the corresponding relationship between hydrogen content and phase composition in zirconium hydride basically conforms to the Zr-H phase diagram published in literature.In different zirconium hydrides,the hydrogen tended to occupy tetrahedral interstitial positions in the unit cell.Compared to commonly observed hydrogen rich face centered tetragonal(fct) ε phase hydridehydride,in which(nearly) all eight tetrahedral positions were fully(without loss of generality,now referred as ε-ZrH2) occupied by hydrogen,and non-stoichiometricface centered cubic(fcc) δ phase hydride,which had the same sites partially and randomly filled.The lattice constants of zirconium hydride with different hydrogen content were different due to different hydrogen atom occupancy.The influence of hydrogen content on the lattice constant and cell volume of δ phase hydride(fcc) and ε phase hydride(fct) was obtained through refined analysis of XRD results as followed:as the hydrogen content increased,the lattice c

关 键 词：锆合金 残余应力 氢化物 晶格常数 

分 类 号：TK91[动力工程及工程热物理]