Unraveling the Role of Interfaces on the Spall Failure of Cu/Ta Multilayered Systems
Unraveling the Role of Interfaces on the Spall Failure of Cu/Ta Multilayered Systems
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DOI：
10.1038/s41598-019-57048-9
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发表时间：
2020-01-14
影响因子：
4.6
通讯作者：
Dongare, Avinash M.
中科院分区：
文献类型：
--
作者：
Chen, Jie;Mathaudhu, Suveen N.;Dongare, Avinash M.
采用分子动力学模拟方法研究了面心立方/体心立方界面的类型和间距对变形和层裂行为的影响。使用模型Cu/Ta多层膜与六种不同类型的接口进行模拟。结果表明，界面类型可以显著影响入射冲击波的结构和强度，改变激活滑移系，改变位错滑移和孪晶行为，影响空泡在溅射过程中的形核位置和形核方式以及由此产生的层裂强度。此外，上述方面受界面间距的显著影响。当界面间距减小到6 nm时，发生了从均匀位错形核到异质位错形核的转变。根据界面类型和间距，损伤（空隙）成核和层裂失效观察到不仅发生在Cu/Ta界面，而且在较弱的Cu层内部，甚至在较强的Ta层内部，虽然不同的机制下，这三种不同的故障模式。这些研究结果表明，根据界面类型和间距的组合，界面可以导致Cu/Ta多层微结构的强化和弱化。
Molecular dynamics (MD) simulations are carried out to investigate the effects of the type and spacing of FCC /BCC interfaces on the deformation and spall behavior. The simulations are carried out using model Cu/Ta multilayers with six different types of interfaces. The results suggest that interface type can significantly affect the structure and intensity of the incoming shock wave, change the activated slip systems, alter dislocation slip and twinning behavior, affect where and how voids are nucleated during spallation and the resulting spall strength. Moreover, the above aspects are significantly affected by the interface spacing. A transition from homogeneous to heterogeneous dislocation nucleation occurs as the interface spacing is decreased to 6 nm. Depending on interface type and spacing, damage (voids) nucleation and spall failure is observed to occur not only at the Cu/Ta interfaces, but also in the weaker Cu layer interior, or even in the stronger Ta layer interior, although different mechanisms underlie each of these three distinct failure modes. These findings point to the fact that, depending on the combination of interface type and spacing, interfaces can lead to both strengthening and weakening of the Cu/Ta multilayered microstructures.