Competing mechanisms between dislocation and phase transformation in plastic deformation of single crystalline yttria-stabilized tetragonal zirconia nanopillars

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• 作者：Ning Zhang ; Mohsen Asle Zaeem ; ^{zaeem@mst.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Zirconia ; Molecular dynamics ; Dislocation ; Phase transformation ; Crystallographic orientations
• 刊名：Acta Materialia
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：120
• 期：Complete
• 页码：337-347
• 全文大小：4234 K

文摘

Molecular dynamics (MD) is employed to investigate the plastic deformation mechanisms of single crystalline yttria-stabilized tetragonal zirconia (YSTZ) nanopillars under uniaxial compression. Simulation results show that the nanoscale plastic deformation of YSTZ is strongly dependent on the crystallographic orientation of zirconia nanopillars. For the first time, the experimental explored tetragonal to monoclinic phase transformation is reproduced by MD simulations in some particular loading directions. Three distinct mechanisms of dislocation, phase transformation, and a combination of dislocation and phase transformation are identified when applying compressive loading along different directions. The strength of zirconia nanopillars exhibits a sensitive behavior depending on the failure mechanisms, such that the dislocation-mediated deformation leads to the lowest strength, while the phase transformation-dominated deformation results in the highest strength.