Atomistic investigation of pseudoelasticity in zirconia nanopillars

Abstract

Molecular dynamics simulations are performed to investigate the underlying atomistic mechanism of the pseudoelastic behavior of zirconia nanopillar. For the [0 0 1]-oriented zirconia nanopillar subjected to uniaxial compressive loading, the strain up to 13.1% can be recovered through inverse martensitic transformation, while larger strain leads to the loss of pseudoelasticity. The irreversible deformation arises owing to the crack propagation, which results from the shear deformation along the phase interfaces. The energy and stress analysis reveals that the responsible mechanism for the pseudoelasticity is the high surface-stress-induced internal stresses at the nanometer scale. The size effect on the martensitic transformation and pseudoelasticity is also elucidated. The simulation results facilitate our understanding of the pseudoelasticity in zirconia nanopillar at the atomic scale.