Sintering mechanism of copper nanoparticle sphere-plate of crystal misalignment: A study by molecular dynamics simulations

Sintering mechanisms of copper nanoparticles on copper plates are investigated based on molecular dynamics (MD) simulation. In this paper, the roles of tilt grain boundaries (GBs) and S5 twisted GBs on sintering kinetics are considered. Regardless of the diameter of the nanoparticle sphere, it is observed that stacking faults and dislocations are formed near the GBs by crystal analysis at the early stage of sintering and throughout the entire sintering process. The stacking faults are overflowed to the surface during the constant temperature stage. The tilt GBs disappears rapidly at the initial stage of sintering, while the S5 GBs is instantly eliminated in the middle temperature region of sintering by the rigid rotation of the nanoparticle sphere. Moreover, besides the contribution of atom diffusion in sintering neck growth, misalignment between the two particles brings about enhanced GBs diffusion. These observations provide insights into the tailored high-angle GBs applicable to nano-scale sphere-plate samples. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study investigates the sintering mechanisms of copper nanoparticles on copper plates using molecular dynamics simulation, revealing the important roles of tilt grain boundaries and S5 twisted GBs in sintering kinetics. Crystal analysis shows the formation of stacking faults and dislocations near the GBs, with stacking faults overflowing to the surface during constant temperature stages. The rigid rotation of nanoparticle spheres eliminates S5 GBs and enhances GB diffusion through misalignment between particles.