МЕЗОСКОПІЧНА МОДЕЛЬ ДИФУЗІЙНОЇ ВЗАЄМОДІЇ ТА РОСТУ ФАЗ В СИСТЕМІ Cu-Sn

Abstract

The model of interdiffusion in system Cu - Cu 8 at.% Sn depending on the form of interface was made in this work. The model sample is a diffusion pair of Cu and Cu 8 at.% Sn, which was thermally annealed at the temperature of 741°C. In this simulation was used the kinetic-thermodynamic approach, which included the calculation of diffusion flux, chemical potentials and Onzager coefficients for the Cu-Sn system phases Calculations of Gibbs potentials for pure components and a solid solution of the Cu-Sn system were carried out using CALPHAD technology.Simulation of diffusion evolution in the sample allows us to calculate the concentration profiles, the positions of the interphase boundaries, the width of the diffusion zone, to estimate the change in the roughness of the interphase boundary during the diffusion reaction. The following roughness parameters are calculated: arithmetical mean deviation of the assessed profile, root mean squared, maximum valley depth, maximum peak height, maximum height of the profile, the skewness and kurtosis. We investigated influence diffusion interaction on the change of roughness of the interphase boundary in model samples. As the size of the projections increases, namely maximum valley depth and maximum peak height, the thickness of the resulting diffusion zone increases. The diffusion annealing smoothes out the interphase limits and reduces their roughness (sample 2-4). In the future we plan to develop a two-dimensional model of diffusion interaction in the Cu-Sn pair in the presence of intermediate phase Cu-Sn in diffusion zone and the presence of initial interfaces with different roughness and structure.