Computational Investigation of the Evolution of Intermetallic Compounds Affected by Microvoids During the Solid-State Aging Process in the Cu-Sn System.

In this work, the impact of microvoids on the microstructural evolution of η-CuSn and ɛ-CuSn in the Cu-Sn system is evaluated numerically. Through the use of the multiphase-field method, the systems of interest are allowed to evolve using a solid-state aging temperature of 453 K in conjunction with material parameters and reaction conditions adopted from previous research. The simulation results are then analyzed and compared with previous experiments in terms of the morphological evolution of the intermetallic compounds (IMCs), the IMC layer thicknesses, and the corresponding interfacial roughness. It is shown that the presence of microvoids at the ɛ/Cu interface interferes with the flow of mass throughout the phases, impeding phase transformations and grain coarsening. This ultimately affects the IMC coarsening rate and overall IMC layer thicknesses. Additionally, it was observed that the presence of microvoids at the ɛ/Cu interface affects the formation of both IMC layers and their corresponding interfaces, and the changes in roughness for the interfaces are quantitatively provided. Overall, the simulations are found to be within the range of accepted experimental values for the morphology of the IMC grains, the evolution of IMC layer thicknesses, and the evolution of interface roughness. [ABSTRACT FROM AUTHOR]