论文部分内容阅读
用离散变分 X_α原子簇方法计算了 Ti_3Sn 及加入 Nb 后的电子结构。键级(Bo)和态密度(DOS)的分析结果表明:Ti_3Sn 中 Ti-Sn 间相互作用主要是 Sn 的5p 轨道与 Ti 的3d,4s,4p 轨道的作用。由于在 Ti—Sn 相互作用中 p-p 作用较强,导致 Ti_3Sn 的脆性较强。对基面和柱面的键级分析结果表明:基面滑移时须破坏较多的近邻 Ti-Sn 键,滑移时需较大的剪切应力,柱面滑移改变的 Ti-Sn 键较少,容易滑移,因而Ti_3Sn 多晶形变时主要是柱面滑移。加入 Nb 后,p—p 成分显著减少,对 Ti_3Sn 起到韧化作用;同时键级增加,因而亦有强化作用。计算结果表明,Nb 在 Ti_3Sn 中随机地占据 Ti 或 Sn 的位置。
The electronic structure of Ti_3Sn and addition of Nb was calculated by the discrete variation X_α cluster method. The results of bond-level (Bo) and density of states (DOS) show that the interaction between Ti-Sn in Ti3Sn is dominated by the 5p orbit of Sn and the 3d, 4s and 4p orbitals of Ti. Due to the strong p-p interaction in the Ti-Sn interaction, Ti 3 Sn is more brittle. The key-level analysis of the basal plane and the cylinder surface shows that the Ti-Sn bond must be destroyed when the base surface slips and more Ti-Sn bonds are required when sliding. Less, easy to slip, and thus Ti_3Sn polycrystalline deformation is mainly cylindrical glide. After adding Nb, the p-p component is significantly reduced, toughening effect Ti_3Sn; while key-level increases, which also have enhanced. The calculation results show that Nb occupies the position of Ti or Sn randomly in Ti_3Sn.