摘要
根据位错的弹性理论 ,建立了 9Ni钢中 5 3°掺杂小角度晶界的原子模型 ,利用Recursion方法 ,计算了杂质在 5 3°小角度晶界典型环境中的能量和电子结构 ,由此得出 ,钢中小角度晶界的强度敏感地依赖于隔离杂质的类型 ,S ,P杂质使晶粒间结合减弱 ,从而导致晶界疏松 ;相反 ,B ,C ,N则会使晶界间的结合加强 .在所有的杂质中 ,B显示出独特的性质 ,在钢中B不仅能增强晶界的结合 ,而且由于占位竞争效应会使其他杂质远离晶界 ,具有净化晶界的作用 .
A model of 5.3° low angle grain boundaries in steel is set up by using elastic theory of dislocations.The first\|principle calculations of energies and the electronic structures of impurities for a 5.3° low angle grain boundary (GB) in steel have revealed important features of the impurity effect.In Fe,impurities such as S,P weaken the intergranular cohesion,resulting in ‘loosening’ of the GB.The presence of B,C,N on the contrary enhances the GB.Boron plays a dual role in steel,not only does it presence at GBs enhance the intergranular cohesion,but also accomplishes ‘site competition cleaning’ by displacing the other impurity atoms off the GB.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第7期1344-1347,共4页
Acta Physica Sinica
基金
国家"95"科技攻关项目基金! (批准号 :98 A2 8 0 1 0 2 )
关键词
小角晶界
杂质
占位竞争
钢
电子结构
掺杂效应
low angle grain boundaries, impurities, site competition effect, grain boundary segregation
