Influence of stress state on the evolution of misfit dislocation networks in a Ni‐based single crystal superalloy
Influence of stress state on the evolution of misfit dislocation networks in a Ni‐based single crystal superalloy
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DOI：
10.1080/14786435.2011.648227
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发表时间：
2012-04
影响因子：
1.6
通讯作者：
Wenping Wu;Ya-Fang Guo;Yuesheng Wang
中科院分区：
文献类型：
--
作者：
Wenping Wu;Ya-Fang Guo;Yuesheng Wang
采用分子动力学（MD）方法模拟了不同应力状态下镍基单晶高温合金界面位错网络的结构演化。从模拟中我们发现，位错网络在不同的应力状态下表现出不同的变形和损伤机制。（100）相界面处的正方形位错网络在[100]单轴载荷下最容易损坏，但在多轴载荷下更难损坏。这表明[100]方向轴向载荷的施加是导致方形位错网络损伤的关键因素，从而导致镍基单晶高温合金在[100]轴向离心载荷下失效。此外，基于分子动力学模拟，探讨了应力状态对γ′筏化的影响。结果表明，γ′筏的形态取决于不同应力状态下位错网络的损伤结构。
The structural evolution of interfacial dislocation networks in a Ni‐based single crystal superalloy under various stress states was simulated by molecular dynamics (MD). From the simulation, we found that the dislocation network exhibits different deformation and damage mechanisms under various stress states. The square dislocation network at the (100) phase interface is the easiest to damage under a [100] uniaxial load, but more difficult to damage when multi‐axial loads are applied. This suggests that the application of a [100] direction axial load is the key factor for the damage of the square dislocation network, which leads to failure of the Ni‐based single crystal superalloy under the [100] axial centrifugal load. Moreover, based on MD simulations, the effects of the stress state on γ′ rafting were explored. The results indicate that the morphology of γ′ raft depends on the damage structures of the dislocation network under various stress states.