Atomistic simulation of α‐Al2O3 nanoparticle plastic anisotropy under compression

Abstract

AbstractAlumina (α‐Al2O3) is one of the major ceramic oxides commonly used for its advanced mechanical properties. Since recently, nanoscale α‐Al2O3 requires more in‐depth characterization related to ceramic powder compaction and sintering as well as for applications in the field of biomedical engineering. In this study, we use classical molecular dynamics simulations with a 2/3‐body interatomic potential to investigate the mechanical response and the elementary deformation processes of α‐Al2O3 nanoparticles under compression. Results show that α‐Al2O3 nanoparticles resist up to particularly elevated critical force before yielding due to a surface nucleation process including various kinds of dislocations and nanotwins strongly sensitive to orientation and temperature. Results are rationalized in terms of stacking‐fault energy and shear stress analysis and are discussed in the light of recent micromechanical tests as well as more fundamental observations performed in the bulk material.