Effect of Interface Phase Transformations on Diffusion and Segregation in High-Angle Grain Boundaries
Effect of Interface Phase Transformations on Diffusion and Segregation in High-Angle Grain Boundaries
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DOI：
10.1103/physrevlett.110.255502
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发表时间：
2013-06-18
影响因子：
8.6
通讯作者：
Mishin, Y.
中科院分区：
文献类型：
--
作者：
Frolov, T.;Divinski, S. V.;Mishin, Y.
最近在Cu中的Sigma 5（310）晶界（GB）中Ag杂质扩散的实验测量揭示了一种不寻常的非Arkenius行为，暗示了可能的结构转变Divinski等人，[B 85，144104（2012）]。另一方面，原子计算机模拟最近发现了金属中高角度GB的相变Frolov等人，[Nat. Commun. 4，1899（2013）]。在这封信中，我们报告的原子模拟银扩散和偏析在两个不同的结构相的Cu西格玛5（310）GB转换到对方的温度。与实验数据的良好协议，验证了实验中看到的不寻常的扩散行为是由相变引起的假设。模拟还预测，低温GB相表现出单层偏析模式，而高温相具有双层偏析。总之，模拟和实验提供了第一个令人信服的证据，在高角度金属GB的结构相变的存在，并证明其检测GB扩散测量和原子模拟的可能性。
Recent experimental measurements of Ag impurity diffusion in the Sigma 5(310) grain boundary (GB) in Cu revealed an unusual non-Arrhenius behavior suggestive of a possible structural transformation Divinski et al., [Phys. Rev. B 85, 144104 (2012)]. On the other hand, atomistic computer simulations have recently discovered phase transformations in high-angle GBs in metals Frolov et al., [Nat. Commun. 4, 1899 (2013)]. In this Letter we report on atomistic simulations of Ag diffusion and segregation in two different structural phases of the Cu Sigma 5(310) GB which transform to each other with temperature. The obtained excellent agreement with the experimental data validates the hypothesis that the unusual diffusion behavior seen in the experiment was caused by a phase transformation. The simulations also predict that the low-temperature GB phase exhibits a monolayer segregation pattern while the high-temperature phase features a bilayer segregation. Together, the simulations and experiment provide the first convincing evidence for the existence of structural phase transformations in high-angle metallic GBs and demonstrate the possibility of their detection by GB diffusion measurements and atomistic simulations.