Ti/Si杂质对Al晶界影响的研究

根据局域密度泛函理论,用第一性原理的赝势方法计算了AlΣ9倾侧晶界掺杂Ti和Si元素前后的原子及电子结构,进而研究杂质偏析对Al晶界的影响.计算结果表明,两种情形均形成了较强的具有共价-金属混合性质的化学键,从而阻止了应力作用下的原子重组,所以均可归于"bond mobility model".

Study of Effects of Titanium and Silicon Impurities on Al Grain Boundary

Based on the local density functional theory,the atomic and electronic structures of the Al sigma 9 tilt grain boundary with segregated impurity atoms have been calculated by a first-principles pseudopotential method,so the effects of segregated impurities on Al grain boundary can be studied,the segregated impurities are titanium and silicon.According to the computing results,both of the two cases form the covalent-mentallic character mixing bonds between impurity atoms with the neighboring Al atoms.These bonds should prevent the rearrangement of atoms under stresses,so it can be classified into the bond mobility model.