Microstructural evolution, shocking sintering mechanism and dynamic mechanical behaviours of silica nanoparticles acting as catalyst carrier in energetic nanomaterials during shock-wave impact

Abstract

In this work, the collision dynamics, sintering mechanism and contact behaviours of silica nanospheres subjected to high-speed impact using reactive Tersoff force field have been explored through molecular dynamics (MD) simulations. During the high-speed impact between silica nanoparticles, there will exist sticking, bouncing off, sintering and even breakage of silica nanoparticles, contingent upon the magnitude of initial impact velocity. The sintering mechanism and collision dynamics between silica nanoparticles have been monitored from various aspects including coefficient of restitution, shear strain, velocity distribution, atomic migration, coordination number and hole evolution, etc. Moreover, the contact behaviours including contact force, contact radius and mean contact stress have also been analyzed and comparisons with continuum models have been made. The continuum models still hold at small impact velocity and small displacement, but small deviation of contact radius and contact force from models can be observed.

Keywords

• Silica nanoparticle
• High speed impact
• Shock sintering
• Contact mechanics
• Collision dynamics