Abstract

A mathematical apparatus for studying interdiffusion in three-component systems, using a theoretical approach similar to that previously proposed for describing interdiffusion in binary alloys, has been developed. This approach takes into account the active role of vacancies without assuming their equilibrium distribution; therefore, the equations for component fluxes contain contributions due to the vacancy density gradient. Solutions of a linearized system of interrelated diffusion equations for three components and vacancies are obtained. It has been found that the time dependences of the component density distributions in the diffusion zone, up to terms having a higher order in the expansion in powers of the vacancy concentration, are determined by two coefficients of interdiffusion. These coefficients depend nonlinearly on the component concentrations and the self-diffusion coefficients.

中文翻译：

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三元合金中的相互扩散理论

摘要

已经开发了一种用于研究三组分系统中的相互扩散的数学装置，其使用的理论方法类似于先前提出的用于描述二元合金中的相互扩散的理论方法。这种方法考虑了空缺的积极作用，而不假设它们的均衡分布；因此，分量通量方程包含由于空位密度梯度引起的贡献。获得了三个成分和空位的相关扩散方程的线性化系统的解。已经发现，扩散区中组分密度分布的时间相关性，直到在空位浓度的幂次方中具有更高阶的项，由两个相互扩散系数确定。