Application of distribution functions in accurate determination of interdiffusion coefficients

Area of Science:

• Materials Science
• Physical Chemistry
• Chemical Engineering

Background:

• The Boltzmann-Matano method is standard for determining interdiffusion coefficients.
• Its accuracy relies heavily on fitting continuous functions to discrete experimental data.
• Challenges arise with complex diffusion profiles and uphill diffusion.

Purpose of the Study:

• To propose and validate the use of various distribution functions to enhance the Boltzmann-Matano method.
• To improve the accuracy of interdiffusion coefficient evaluation.
• To provide a general solution for diffusion analysis in diverse materials.

Main Methods:

• Application of normal, pseudo-normal, skew normal, and pseudo-skew normal distribution functions for simple D-c relations.
• Utilizing superposed distributions for complex D-c relations.
• Employing combined superpositions for cases involving uphill diffusion.

Main Results:

• Accurate interdiffusion coefficients were successfully obtained using the proposed distribution functions.
• Validation was performed on benchmark and real alloy systems.
• The method demonstrated robustness across different diffusion scenarios.

Conclusions:

• Distribution functions significantly improve the accuracy of the Boltzmann-Matano method.
• This enhanced approach offers a reliable solution for determining interdiffusion coefficients.
• The proposed method is anticipated to be a general solution for materials diffusion analysis.