Measuring simulated hydrogen diffusion in symmetric tilt nickel grain boundaries and examining the relevance of the Borisov relationship for individual boundary diffusion
Measuring simulated hydrogen diffusion in symmetric tilt nickel grain boundaries and examining the relevance of the Borisov relationship for individual boundary diffusion
复制标题
测量对称倾斜镍晶界中的模拟氢扩散并检查鲍里索夫关系与各个边界扩散的相关性
DOI：
10.1016/j.actamat.2021.116882
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发表时间：
2021
期刊：
影响因子：
9.4
通讯作者：
E. Homer
中科院分区：
文献类型：
--
作者：
D. E. Page;Katherine Varela;Oliver K. Johnson;D. Fullwood;E. Homer
众所周知，晶界是金属中重要的扩散途径。本文研究了不同晶界类型对氢在镍晶界中的扩散的影响。我们模拟了在不同温度下的26[1 0 0]对称倾斜晶界，并开发了一种改进的均方位移法来分离晶界扩散系数和体扩散系数。我们对不同边界的扩散系数数据进行了分析，发现晶界扩散系数高于体扩散系数，直到两者收敛的温度。我们测试了Borisov等人开发的一个模型。满足。金属学报，1994,17,80-84)，将晶界扩散与晶界界面能联系起来。尽管鲍里索夫关系以前从未被用于研究溶质间隙扩散，但它很好地拟合了晶界扩散系数高于体扩散系数的温度下的模拟扩散数据。鲍里索夫关系中的一些参数与晶界的几何形状及其激活状态有关，由于它们难以测量或获得，因此总是采用假设值。模拟数据的拟合为这些值提供了物理上真实的估计，并提供了应该重新考虑传统假设值的使用的证据。这项工作还表明，虽然需要进一步验证，但鲍里索夫关系可以合理地将氢的溶质间隙扩散率与单个[1 0 0]对称倾斜镍晶界的界面能联系起来，而在过去，它已被用于将晶界网络的自扩散和界面能作为一个整体联系起来。
Grain boundaries are known to act as important diffusion pathways in metals. Here we examine how hydrogen diffusion in nickel grain boundaries is affected by different grain boundary types. We simulate 26 [1 0 0] symmetric tilt grain boundaries at several temperatures and develop a modified mean squared displacement method for isolating the grain boundary diffusivity from the bulk diffusivity. We analyze the diffusivity data for the different boundaries and find the grain boundary diffusivity to be higher than the bulk diffusivity up to a temperature where the two converge. We test a model developed by Borisov et al.(Phys. Met. Metallogr. 17, 1964, 80-84) that relates grain boundary diffusion to grain boundary interfacial energy. Despite the fact that the Borisov relationship has never been used to examine solute interstitial diffusion before, it fits the simulated diffusion data well for temperatures where the grain boundary diffusivity is higher than the bulk diffusivity. Some parameters in the Borisov relationship, related to the geometry of the grain boundary and its activated states, have always taken on assumed values because they are hard to measure or acquire. The fit of the simulated data provides estimates for these values that are physically realistic and provides evidence that the use of the traditionally assumed values should be reconsidered. This work also demonstrates that while there is a need for further validation, the Borisov relationship can reasonably relate solute interstitial diffusivity of hydrogen to the interfacial energy of individual [1 0 0] symmetric tilt nickel grain boundaries, whereas in the past it has been used to relate self diffusion and interfacial energy of a grain boundary network as a whole.
影响因子：
8.6
作者：
Frolov, T.;Divinski, S. V.;Mishin, Y.
通讯作者：
Mishin, Y.
影响因子：
3.7
作者：
Divinski, Sergiy V.;Edelhoff, Henning;Prokofjev, Sergei
通讯作者：
Prokofjev, Sergei