Cu-Ni-Sn固溶体溶质原子与位错交互作用的第一性原理计算

First-principles Calculation of Interaction between Solute Atoms and Dislocations in Cu-Ni-Sn Solid Solution

通过第一性原理计算了Cu-Ni-Sn固溶体中刃型位错对溶质原子的交互作用能。结果表明,位错对Sn原子的作用力很强,且随着基体中Ni含量升高而增大。纯铜基体中位错对单个不同位置Sn原子的最大作用能量差约为89.83kJ/mol,Ni含量为20%的Cu-Ni合金基体中位错对单个不同位置Sn原子的最大作用能量差约为128.25kJ/mol。Sn原子择优分布在正刃型位错下方G位置,离位错较远的Sn原子在能量差作用下向位错正下方G位置周围偏聚。固溶体中的位错对Ni原子的作用较弱(最大作用能量差约为18.87kJ/mol),且Ni原子在位错作用下的择优分布不明显。

The interaction energies of solute atoms with edge dislocation pairs in Cu-Ni-Sn solid solutions were calculated by first principles.The results show that the dislocation has a strong force on Sn atom and it is increased with the increase of Ni content in the matrix.The maximum energy difference of dislocations acting on a single Sn atom is about 89.83 kJ/mol at different positions in pure copper matrix,and that on single Sn atom at different positions in(Cu,Ni)matrix containing 20%Ni is about 128.25 kJ/mol.The preferred distribution of Sn atoms is at the Gposition just below the front edge dislocations,and the Sn atoms far away from the dislocations converges around the Gposition under the action of energy difference.Dislocation in solid solution has a weak interaction energy to Ni atom(the maximum energy difference about 18.87 kJ/mol),and the preferential distribution of Ni atom under dislocation is not obvious.