Abstract: Pressure-assisted sintering (PAS) utilizing bimetallic core-shell nanoparticles (CS NPs) has garnered widespread attention for its ability to produce advanced components with excellent thermal and electrical conductivities, even at low temperatures. This study presents the first investigation into the PAS of bimetallic CS NPs, using Ag-coated Cu material as a representative system, through all-atom molecular dynamics (MD) simulations. The study provides detailed insights into the atomic-scale processes and mechanisms that govern pressure-assisted sintering, elucidating the coalescence phenomena and revealing the significant influence of external pressure. By comparing atomistic behaviors, such as diffusion, migration, and microstructure evolution, between PAS and thermal sintering, a deeper understanding of the underlying mechanisms is achieved. Furthermore, the results highlight the importance of considering microstructural characteristics in addition to void fraction assessment for accurately estimating mechanical properties. This study enhances our understanding of sintering methods and offers a new perspective on designing process conditions in the PAS process.

Key words: Core-shell nanoparticles, Pressure-assisted sintering, Molecular dynamics simulation, Many-particle model, Microstructure, Mechanical properties