An Atomistic Study on Sintering Mechanisms of Metal Nanopowders: Case Study of Cu-Ag Nanoparticles

BA Mohammed and RS Batbooti, JOM, 77, 5126-5135 (2025).

DOI: 10.1007/s11837-025-07393-0

Utilizing the molecular dynamics approach, the sintering mechanisms of Cu-Ag nanopowders have been studied. To evaluate the microstructural changes of Cu and Ag nanoparticles during sintering at different temperatures, all stages of the coalescence process were analyzed, and the results demonstrate that sintering first initiates due to the free rotation of nanoparticles and is then accelerated by curvature effects, further continuing through atomic surface diffusion. As the temperature increases, the microstructure of the interface region turns amorphous. Dislocation analysis results show that the first Shockley partial dislocations and stacking faults nucleate from the Cu/Ag interface. It is revealed that dislocation slip and stacking fault expansion are responsible for the plastic deformation at the Cu/Ag interfacial region, resulting in necking growth in the initial stages of sintering. A comparison of the final microstructure of sintered samples at 600-1200 K suggests that increasing temperature would increase particle merging, bulk atomic diffusion, and enhance crystallographic defect density within the particles. Moreover, the uniaxial tension outcomes indicated an increase in the yield strength and elastic modulus with the sintering temperature, which was attributed to the thickened interface between the two nanoparticles.

Return to Publications page