Application of numerical inverse method in calculation of composition-dependent interdiffusion coefficients in finite diffusion couples

Yuanrong Liu,Jing Zhong,Ming Chen,Weimin Chen,Lijun Zhang

doi:10.30544/308

Abstract

The previously developed numerical inverse method was applied to determine the composition-dependent interdiffusion coefficients in single-phase finite diffusion couples. The numerical inverse method was first validated in a fictitious binary finite diffusion couple by pre-assuming four standard sets of interdiffusion coefficients. After that, the numerical inverse method was then adopted in a ternary Al-Cu-Ni finite diffusion couple. Based on the measured composition profiles, the ternary interdiffusion coefficients along the entire diffusion path of the target ternary diffusion couple were obtained by using the numerical inverse approach. The comprehensive comparisons between the computations and the experiments indicate that the numerical inverse method is also applicable to high-throughput determination of the composition-dependent interdiffusion coefficients in finite diffusion couples.

Highlights

High-throughput measurement of accurate interdiffusion coefficients is of great significance for diffusion and kinetic studies in various materials processes [1,2]
Fictitious binary system To validate whether the pragmatic numerical inverse method is applicable in binary finite diffusion couple, a series of hypothetic composition profiles generated from four types of pre-assumed interdiffusivities were chosen as the target
Summary Considering that the traditional Boltzmann-Matano method and its variants have a complex process for calculation of interdiffusion coefficients in finite diffusion couples, especially for ternary and higher-order systems or the cases with up-hill diffusion phenomenon, the previously developed pragmatic numerical inverse method was adopted to determine the composition-dependent interdiffusion coefficients in single-phase finite diffusion couples

Summary

Introduction

High-throughput measurement of accurate interdiffusion coefficients is of great significance for diffusion and kinetic studies in various materials processes [1,2]. The solid semi-infinite diffusion couple is the frequently used experimental technique for measurement of interdiffusion coefficients in the target phase. Sometimes, when the total thickness of the diffusion couple is not large enough or the diffusion time is too long, diffusion distance may exceed the entire domain. In this case, the predefined semi-infinite diffusion couple turns out to be a finite one. Different from the semi-infinite diffusion couple, such finite diffusion couple has seldom been employed to measure the interdiffusion coefficients in the target phase

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