Lattice and Grain Boundary Diffusion in Polycrystals
Lattice and Grain Boundary Diffusion in Polycrystals
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DOI：
10.2320/matertrans1960.2.25
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发表时间：
1961
影响因子：
1.2
通讯作者：
T. Suzuoka
中科院分区：
文献类型：
--
作者：
T. Suzuoka
示踪剂扩散机制。通过假设与晶粒内部相比沿晶粒边界沿着的高扩散率和扩散剂守恒，讨论了具有平面源的多晶介质。从问题的解析解中得到以下理论结果。(1)在一个小的渗透区域，晶界作为汇，即。e.对扩散剂量的负贡献来自于晶界。(2)在一个大的渗透深度，他们作为源，和晶界扩散的合成积极的贡献是这样的，从边界到内部的扩散剂的平均浓度的对数线性依赖于渗透深度的6/5功率。(3)考虑到晶粒尺寸，本理论预测的渗透曲线中，晶格和晶界扩散起着重要的作用。(4)该理论还发现了晶格扩散的贡献比晶界扩散的贡献占主导地位的条件。给出了一个可用于由实验数据确定晶界扩散系数的关系式。这些理论结果与实验数据吻合得很好。本模型的有效性的限制进行了讨论。（1961年3月8日）
Tracer diffusion mechanism in. a polycrystalline medium with a plane source is discussed by assuming both the high diffusivity along the grain boundaries as compared with that inside the grains and the conservation of diffusant. The following theoretical results are obtained from the analytical solution of the problem. (1) In a small penetration region the grain boundaries act as sinks, i. e. a negative contribution to the amount of diffusant arises from the grain boundaries. (2) At a large penetration depth they act as sources, and the resultant positive contribution of grain boundary diffusion is such that the logarithm of the average concentration of diffusant from the boundary into the inside depends linearly on the 6/5 power of penetration depth. (3) Considering the grain size the present theory predicts the penetration curve in which both the lattice and the grain boundary diffusion play an important role. (4) The theory also finds the condition that the contribution from the lattice diffusion becomes dominant as compared with that from the grain boundary. A relation usable for the determination of the grain boundary diffusion coefficient from experimental data is given. These theoretical results are found in agree well with the experimental data. The limit for the validity of the present model is also discussed. (Received March 8, 1961)