锆晶体孪晶缺陷对氢偏析影响的弹性复势分析  

Elastic potential analysis of hydrogen segregation affected by twinning defects in zirconium crystals

作　　者：刘晨阳 谢超 LIU Chenyang;XIE Chao(Faculty of Mechanical Engineering&Mechanics,Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学机械工程与力学学院,浙江宁波315211

出　　处：《宁波大学学报（理工版）》2024年第6期61-66,共6页Journal of Ningbo University：Natural Science and Engineering Edition

基　　金：国家自然科学基金(12272192);浙江省自然科学基金(LY22A020002);宁波市重点研发计划(2023Z012)。

摘　　要：锆作为核反应堆包壳和堆芯结构材料,常工作在高温和水循环环境,电化学腐蚀产物进入基体内形成的氢化物对锆的强度和韧性都有显著影响.运用平面弹性复势方法对锆晶体中常见三种孪晶缺陷引起的应力场以及氢在锆中的应力辅助扩散进行建模与求解,以向错四极子模拟孪晶面缺陷,将浓度梯度和静水应力梯度控制的氢输运处理成非齐次拉普拉斯方程,分析孪生类型与厚长比对氢化物生长趋势的影响.结果显示:(1)在孪晶首尾端处均存一个氢原子高度集中区域,这种氢偏析区域相对于孪生呈对称分布,其中■孪晶因为晶格切变最大引起的氢偏析最强;(2)孪晶厚长比越大,孪晶尖端的氢浓度越高,越有利于氢化锆沉淀;(3)锆在加工成型中生成的孪晶面缺陷对氢化物形核和生长有显著的调控作用.As the cladding and core structural material of nuclear reactor,zirconium often works in high temperature and water cycle environment.The hydride formed by electrochemical corrosion product entering the matrix has significant influence on the strength and toughness of zirconium.In this paper,the plane elastic complex potential method is used to model and solve the stress field caused by three kinds of twinning and the stress-assisted diffusion of hydrogen in zirconium.The twinning is modeled by the wedge disclination quadrupole.The hydrogen transport controlled by concentration gradient and hydrostatic pressure gradient is treated as a non-homogeneous Laplacian equation.The results show that:(1) There is a highly concentrated region of hydrogen atoms at both the head and tail of the twinning,and this region of hydrogen segregation is symmetrical with respect to the twinning,in which the ■twinning has the strongest hydrogen segregation due to the largest lattice shear;(2) The higher the thickness to length ratio of the twinning,the higher the hydrogen concentration of the twinning tip,the more conducive to the precipitation of zirconium hydride;(3)The defects of twinning surface generated in zirconium processing have a significant regulating effect on the nucleation and growth of hydrides.

关 键 词：锆 孪晶 氢偏析 应力辅助扩散 复势方法 

分 类 号：O343.1[理学—固体力学]