Atomistic simulation of α‐Al₂O₃ nanoparticle plastic anisotropy under compression

Abstract

Alumina (𝛼-Al 2 O 3 ) is one of the major ceramic oxides commonly used for its advanced mechanical properties. Since recently, nanoscale 𝛼-Al 2 O 3 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-Al 2 O 3 nanoparticles under compression. Resultsshow that 𝛼-Al 2 O 3 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.