Determination of accurate interdiffusion coefficients in fcc Ag-In and Ag-Cu-In alloys: A comparative study on the Matano method with distribution function and the numerical inverse method with HitDIC

In this paper, 3 fcc binary Ag-In and 3 fcc ternary Ag-Cu-In diffusion couples were firstly prepared. Based on the measured composition-distance profiles, both the traditional Matano method with distribution functions and the numerical inverse method with HitDIC were then utilized to determine the accurate interdiffusion coefficients in fcc Ag-In alloys at 873 K, 973 K, and 1073 K and Ag-Cu-In alloys at 1073 K. The determined interdiffusivities in fcc Ag-In alloys increases as the composition of In increases. The impurity diffusivities of In in fcc Ag extrapolated from the evaluated interdiffusivities based on the Matano method agree well with the tracer experimental data from the literature. As for fcc Ag-Cu-In alloys, the three-dimensional main interdiffusivities planes at 1073 K were constructed over the investigated composition range. The diffusion rate of In is generally faster than that of Cu. Moreover, the main interdiffusivity of In increases with the increment of both In and Cu concentrations, while the main interdiffusivity of Cu increases with In concentration but decreases with Cu concentration. After that, a comprehensively comparative study on the two methods were performed. The interdiffusivities in both the fcc Ag-In and Ag-Cu-In alloys evaluated from the two methods are consistent with each other, indicating that both methods can result in accurate interdiffusivities in binary and ternary alloys. However, as the number of elements increases, the Matano method becomes inconvenient. While for the numerical inverse method with HitDIC, no such limitation exists, and it can be conveniently applied in alloys with any number of components. (C) 2019 Elsevier B.V. All rights reserved.