层厚度和晶界“阶梯型”缺陷对铜–镍复合薄膜的力学性能的分子动力学模拟研究

The Effect of Layer Thickness and Interfacial Defect with Steps on Mechanical Properties of Cu/Ni Multilayers Thin Film

本文采用分子动力学方法研究了层厚度和“阶梯型”晶界缺陷对铜–镍纳米薄膜的力学性能的影响。模拟结果表明,随着层厚度的增加,薄膜的应力逐渐增大,这是因为材料的层厚度越大,材料存储位错的能力就越强,及屈服强度越高。除此之外,研究结果发现晶界存在“阶梯型”缺陷降低了晶界对于位错传播的阻碍作用,使得铜–镍纳米薄膜屈服强度降低。

The effect of layer thickness and interfacial defect with steps of copper-nickel multilayer thin film on deformation mechanism is investigated by molecular dynamics simulations. The results indicate the yield stress is found to increase with increasing layer thickness. The result is mainly due to the fact that the room for dislocation storage can be affected by the changes of layer thickness. Furthermore, the studies show that interfacial defect with steps dominates interfacial barrier effect, resulting in the lowest yield stress.