Investigation of initial stages of nano-ceramic particle sintering using atomistic simulations

Sintering is an important step in densification of materials. Surfaces play a critical role in sintering, which are magnified for nano-systems (nanowire or nanoparticle). This work focuses on the investigation of the initial stages of nanoparticle sintering by atomistic simulation methods. We have characterized two different distinct systems, Argon clusters and mixed oxide systems, for analysis. Due to better particulate mixing, a combination of nanowire and nanoparticle was easier to sinter than a combination of nanoparticle and nanoparticle for Argon clusters. For a mixed oxide system (rutile-TiO2 and MgO), our results indicate that size, dimensions and structural stability of oxide nano-structures play an important role during sintering. For TiO2 nanowire and MgO nanoparticle system, Ti atoms diffuse faster than Mg atoms, while for TiO2 nanosphere and MgO nanoparticle combination, Mg atoms diffuse faster than Ti atoms during sintering. This diffusion is guided by the relative size and cohesive energies of the nano-systems.

► Structural stability of oxide nano-structures plays an important role during sintering. ► Nanowire–nanoparticle system was easier to sinter than nanoparticle–nanoparticle system. ► Relative cohesive energy provides key information regarding initiating sintering process. ► This study helps on guiding experiments to control the initial structures for better sintering.