Sintering Mechanism of Two Spheres Forming a Homogeneous Solid Solubility Neck [Translated]^†

Abstract

A simulation method for initial-stage sintering was proposed to understand the effect of sintering conditions on the sintering behavior of two particles of different sizes and compositions. This study employed a homogeneous solid solubility system of Cu-Ni. The sintering experiments were performed with two spherical Cu-Ni particles in contact, and the sintered particles were observed by SEM and EDX. It was confirmed that the sintered particles always form a curved neck and copper was the dominant component in the neck.
The proposed simulation method, in which the model for two particles of identical composition was modified, involves several mass transport mechanisms: surface diffusion, volume diffusion, grain-boundary diffusion, evaporation-condensation and, newly, grain growth. The sintering behavior of Cu-Ni particles was simulated using the proposed method and the results were highly similar to the experimental results. It was also found that grain growth was not negligible in initial-stage sintering, and that shrinkage and grain growth responded sensitively to sintering conditions. Consequently, by analysis of these simulation results, it is possible to understand the mechanism of sintering two spherical particles of different compositions and to determine the optimum sintering conditions.

^† This report was originally printed in J. Soc. Powder Technology, Japan, 28(2), 202-210 (2002) in Japanese, before being translated into English by KONA Editorial Committee with the permission of the editorial committee of the Soc. Chemical Engineers, Japan.