Interdiffusion in Ni-rich, Ni-Cr-Al alloys at 1100 and 1200 °C: Part II. Diffusion coefficients and predicted concentration profiles
Interdiffusion in Ni-rich, Ni-Cr-Al alloys at 1100 and 1200 °C: Part II. Diffusion coefficients and predicted concentration profiles
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DOI：
10.1007/bf02647079
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发表时间：
1987-01
期刊：
影响因子：
--
通讯作者：
J. A. Nesbitts;R. Heckel
中科院分区：
文献类型：
--
作者：
J. A. Nesbitts;R. Heckel
在1100和1200 °C下测定了Ni-Cr-Al系Ni固溶体γ（fcc）相的三元互扩散系数。γ/γ和γ/γ + β（β-NiAl结构）扩散偶都得到了广泛的应用。采用两种分析技术计算互扩散系数。当Al和Cr的Matano平面不重合时，进行大量积分计算以确定平均扩散系数并评估Matano平面不重合的影响。扩散系数的测量结果表明，大约是四倍，而和是相同的数量级。在所有浓度下，都是。和都随Al浓度的增加而增加，而和仅对Cr的浓度依赖性很小。采用三元有限差分互扩散模型，利用测得的扩散系数的浓度依赖性来预测γ/γ电偶的浓度分布。在1100 ° C和1200 °C下，预测的浓度分布和测量的浓度分布之间观察到良好的一致性。
Ternary interdiffusion coefficients were measured in the Ni solid solution γ (fcc) phase of the Ni-Cr-Al system at 1100 and 1200 °C. Extensive use was made of both γ/γ and γ/γ + β (β-NiAl structure) diffusion couples. Two analysis techniques were employed to calculate the interdiffusion coefficients. When the Matano planes for Al and Cr were not coincident, numerous integral calculations were made to determine an average diffusion coefficient and to assess the effect of the noncoincidence of the Matano planes. The results of the diffusivity measurements showed thatis approximately four times greater than, whileandare of the same magnitude. For all concentrations,is two to three times greater than. Bothandincrease with increasing Al concentration, whereasandshow little concentration dependence on Cr alone. A ternary, finite-difference interdiffusion model was employed to predict concentration profiles for the γ/γ couples utilizing the concentration dependence of the measured diffusivities. Good agreement was observed between the predicted and measured concentration profiles for both 1100 and 1200 °C.