摘要
为从理论上解释稀土元素在镍基高温合金晶界区的行为本质,建立了镍基高温合金γ相大角度重位点阵晶界模型,应用Recursion方法计算了晶界偏聚稀土元素时的态密度,稀土在晶界的偏聚能以及稀土原子间的相互作用能。计算结果表明:晶界区含有稀土时,态密度双峰的高度有所降低,态密度在高能区明显上移,稀土含量越多其对晶界态密度的影响也越大;稀土原子偏聚于晶界,且主要偏聚于晶界的压缩区;稀土原子间相互排斥,因此在晶界区易形成有序相。稀土与杂质硫相互吸引,其结果是分散和固定部分杂质,改善合金高温性能。
In order to reveal the Denaviors of REatoms on grain boundaries（GB） in Ni-base superalloy in theory, the atomic structure model of high angle grain boundary of γ phase in Ni-base superalloy was set up by the concept of coincidence-site lattice（CSL）. The density of states of the RE atoms on grain boundaries, the segregation energies of the RE atoms and the interaction energies between RE atoms on grain boundary were calculated by recursion method. The calculated results were shown as follows. When grain boundary contained RE atoms, the double peak height of density of state lowered, the density of state rose obviously in high energy region, the more grain boundary contained state of grain boundary. RE atoms segregated to GB and were apt to occupy the sites in the compressed region of GB. RE atoms repelled each other to form ordered phases in the region of GB. RE atoms and impurity S attracted each other to disperse and fix some impurities, which could improve high temperature properties of the superalloy.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2008年第6期731-734,共4页
Chinese Journal of Rare Metals
基金
辽宁省教育厅科研项目计划资助项目(20060661)
沈阳航空工业学院青年教师资助课题(200711Y)
关键词
稀土
晶界
电子理论
rare earth elements
grain boundary
electron theory
作者简介
周永军（1978-），男，辽宁营口人，硕士，工程师。通讯联系人（E-mail：zhouyj@syiae．edu．cn）
