An insight into the temperature-dependent sintering mechanisms of metal nanoparticles through MD-based microstructural analysis

• DOI: 10.1016/j.powtec.2021.03.037
• Publication Date: 2021-03-19T03:11:30Z
• Authors: Abolfazl Malti; Arash Kardani; Abbas Montazeri
• Keywords: Surface diffusion; Atomic diffusion; Atmospheric temperature range; Atomic units

Abstract Carrying out molecular dynamics simulation, we have probed the final microstructure of sintered Cu-Ni nanopowders to introduce a route for finding out the optimal process parameters for metal nanoparticles. As such, a through microstructural analysis is conducted in each case to identify the atomic-scale evolutions in the interfacial region. Firstly, a reverse correlation is found between the solidification time and amorphous content within the samples. It is revealed that in a temperature range of 600–1000 K, the process is controlled by the slip of dislocations. Meanwhile, beyond 1000 K, surface diffusion and thermal twinning are the main mechanisms. Finally, in the case of 100 ps sintering at 1000 K, the combination of dislocations slip and surface diffusion phenomena would result in creating a defectless structure, which introduces these values as the optimal parameters. Moreover, by monitoring the temperature-dependent MSD diagrams, the sintering dynamics is deeply analyzed to complete the discussion.