To understand the atomistic mechanisms of tension failure of Ni-based superalloy, in this study, the classical molecular dynamics (MD) simulations were used to study the uniaxial tension processes of both the Ni/Ni₃Al interface systems and the pure Ni and Ni₃Al systems. To examine the effects of interatomic potentials, we adopted embedded atom method (EAM) and reactive force field (ReaxFF) in the MD simulations. The results of EAM simulations showed that the amorphous structures and voids formed near the interface, facilitating further crack propagation within Ni matrix. The EAM potentials also predicted that dislocations were generated and annihilated alternatively, leading to the oscillation of yielding stress during the tension process. The ReaxFF simulations predicted more amorphous formation and larger tensile strength. The atomistic understanding of the defect initiation and propagation during tension process may help to develop the strengthening strategy for controlling the defect evolution under loading.

中文翻译：

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镍基高温合金拉伸过程的分子动力学研究

为了了解Ni基高温合金拉伸破坏的原子机理，在本研究中，经典分子动力学（MD）模拟被用来研究Ni / Ni ₃ Al界面体系和纯Ni和Ni的单轴拉伸过程。₃铝系统。为了检查原子间电势的影响，我们在MD模拟中采用了嵌入原子方法（EAM）和反作用力场（ReaxFF）。EAM模拟的结果表明，在界面附近形成了非晶结构和空隙，从而促进了Ni基体内裂纹的进一步扩展。EAM电位还预测，位错会交替产生和消除，从而导致张应力过程中屈服应力的振荡。ReaxFF模拟预测更多的非晶形成和更大的拉伸强度。拉伸过程中缺陷的萌生和扩散的原子性理解可能有助于开发强化策略，以控制载荷下缺陷的发展。