Molecular dynamics simulation and experimental verification for bonding formation of solid-state TiO2 nano-particles induced by high velocity collision

摘要： Collision processes of solid-state nano-sized ceramic particles were investigated by molecular dynamics (MD) simulation in order to clarify their bonding mechanisms. Effect of particle temperature on particle bonding formation was examined, and collision behavior of nano-sized TiO2 particle was discussed in terms of particle deformations. Microstructures and bonding qualities of bonded nano-sized TiO2 particles induced by high velocity collision were examined by high resolution transmission electron microscope (HR-TEM) to verify the MD results. Simulation results demonstrate that the bonding formation of nano-sized TiO2 particles can be attributed to the atomic displacement and lattice distortion in localized impact region of particle boundaries. TEM microstructure results prove simulation results and indicate effective chemical bonding formations between nano-particles at low temperature by high velocity collision. Quantitative results show that the high temperature is beneficial to the particle bonding formation. The asperity around nano-sized ceramic particles surface contributes to the displacement and lattice distortion in localized impact region under the high impact compressive pressure. The fact demonstrates a new mechanism of nano-scale ceramic particle bonding formation induced by the localized atomic displacement. The study present opens up a promising prospect of fabricating functional equipment with nano-scale ceramic particles with high velocity collision at ambient temperature.