High speed impact and solid-state deposition of alumina particles: A molecular dynamics study

Abstract

This study provides an atomic-scale description of the high-velocity impact of α-Al2O3 particles onto an α-Al2O3 substrate, with a focus on unraveling the material behavior during Aerosol Deposition (AD). Large-scale Molecular Dynamics (MD) simulations were performed to model two defect-free single-crystal and one bicrystal particles, all with a diameter of 0.2 µm, impacting the substrate at different velocities using quasi-two-dimensional approach. The results suggest that the crystal orientation plays a crucial role in both plasticity and damage of the nanoparticles. As anticipated, we observed a direct correlation between impact velocity and both plasticity and fragmentation. However, the increase in adhesion efficiency remains marginal, suggesting that neither factor significantly impacts the deposition process. On the contrary, our MD results indicate that the crucial element lies in the substrate's surface alterations. These modifications arise from the fragments left on the substrate after impact and their subsequent interactions with incoming particles.