摘要
本文采用第一性原理密度泛函理论研究了Zr元素对UO2结构与力学性能的影响。计算结果表明,随着Zr元素含量的增加,UO2的晶格参数、晶胞体积均逐渐减小。其中,掺杂形成能,U-O键,Zr-O键和O-O键的单位键长随着Zr元素的增加而降低。通过计算其弹性模量,发现Zr含量在20wt%前,随着Zr含量的增加,UO2的体模量略微增大,而剪切模量略微降低;当Zr的含量达到40wt%时,UO2体模量随着Zr含量的增加而明显增大,剪切模量反而增大。同时,随着Zr含量的增加,UO2的B/G值不断增加,材料呈脆性向塑性转变的趋势。
Using density functional theory(DFT),the structure and mechanical properties of Zr-doped UO2 have been investigated.The calculated results show that,with increasing Zr concentration,the lattice parameter and unit-cell volume,decrease gradually and the formation energy and the bond lengths of U-O,ZrO and O-O of UO2 lower,while the bulk modulus of UO2 is enhanced.But the shear modulus of UO2 decrease when Zr concentration below 20wt%.However,the shear modulus of UO2 increased when Zr-doped concentration up to 40wt%.Finally,it is found that UO2 has a trend of brittle-to-ductile with the increase in the concentration of Zr,leading to the increase in the B/G ratio value.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2014年第1期126-129,153,共5页
Journal of Materials Science and Engineering
基金
中核集团预研基金资助项目(YWJJ-ZZYY-13-11-01)
国家自然科学基金资助项目(21301164)
关键词
UO2
弹性性能
脆韧性
第一性原理
UO2
elastic properties
brittle-to-ductile
first-principles
