Study on the melting and sintering behavior of Cu-Fe mixed nanoparticles based on molecular dynamics simulations

• Propose using MD simulations to study the melting and sintering behavior of Cu-Fe mixed nanoparticles. • Systematically analyze the influence patterns of the melting and sintering behavior under multiple factors. • Particle size and Fe content significantly affect the melting point of mixed nanoparticles. • Doping with Fe element inhibits the sintering process and reduces the sintering quality. Understanding the melting and sintering behavior of composite metal nanoparticles is of great significance to promote the synthesis and application of nanomaterials. In this work, molecular dynamics simulation method was employed to examine in detail the influence of sintering temperature, particle size and Fe content on the melting and sintering behavior of Cu-Fe mixed nanoparticles. The results show that the melting point of Cu-Fe mixed nanoparticles exhibits a strong size dependence and gradually increases with the increase in Fe content. High sintering temperatures significantly promotes the sintering process and the degree of atomic migration, and the diffusion behavior on the surface is enhanced, providing a significant driving force for sintering. Since smaller particle sizes have higher surface energy, the relationship between the neck parameters during the sintering process of different particle sizes is 4 nm > 6 nm > 8 nm, and the displacement of surface atoms is always greater than that of internal atoms. As the Fe content increases, the sintering of nanoparticles and the migration of atoms decrease, leading to a lower degree of sintering. This study further provides an atomic-scale theoretical basis for the melting and sintering behavior of Cu-Fe mixed nanoparticles.