镍基高温合金中γ/θ相界面性能的数值模拟

Numerical simulation of interface properties of γ/θ interface in Ni Base Superalloy

摘要:

本文采用分子动力学法以第二近邻嵌入原子势模型(2NN MEAM)的原子间相互作用势为输入参数,研究了Ni-Al-V高温合金中γ/θ-DO₂₂相不同成分下的界面结构,并计算了界面处不同成分下的界面能和界面分离能。研究表明随Al原子浓度增大,界面能增大,界面分离能减少；随V原子浓度增大,界面能先增大后减小；而原子浓度改变对界面分离能影响较小；同时表明界面能和界面分离能与界面迁移密切相关。该结果可用于对Ni-Al-V高温合金沉淀过程界面的成分偏析,界面迁移等动态行为做进一步研究,对高温合金设计有极大的指导意义。

Abstract:

By using molecular dynamics method with the second nearest neighbor modified embedded-atom method (2NN MEAM) interatomic potential, we studied the γ/θ-DO₂₂ interfacial structure of Ni-Al-V superalloy at different compositions, and calculated the interfacial energy and the work of separation on the interfaces. The research shows that with the Al atom concentration increases, the interfacial energy can increase while the work of separation can reduce; with the concentration of V atoms increases, the interfacial energy increases first and then decreases; but the change of atomic concentration has little effect at the work of separation; and the interfacial energy and the work of separation are closely related to the interfacial migration. It has great guiding significance to the alloy design that the results can be used to further study the dynamic behavior of Ni-Al-V superalloys in the process of precipitation, such as the composition segregation and interfacial migration.