|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Computational Design and Simulation of Materials (CDSM 2018): Atomistic Simulations
||Understanding Defect Tolerance and Grain Boundary Effect on Mechanical Properties of Nano-twinned Yttria-stabilized Tetragonal Zirconia
||Ning Zhang, Mohsen Asle Zaeem
|On-Site Speaker (Planned)
Grain boundary (GB) induced phase transformation and amorphous phase formation have been seen as dominant mechanisms accounting for plastic deformation in polycrystalline yttria-stabilized tetragonal zirconia (YSTZ) ceramics. Using molecular dynamics (MD) simulations of compression of nano-twinned YSTZ pillars with pre-existing defects (e.g. void), we show that the stress-strain response of YSTZ nanopillar is insensitive to a pre-existing void as long as its diameter is smaller than a critical value. As the size of nano-void increases to beyond the critical value, the location of nucleation of phase transformation will transit from grain boundaries to the edge of nano-voids. In situ atomic configuration analysis also reveals that this phase transformation is accompanied by crack initiation and propagation from the edge of nanovoid. With the introduction of multiple parallel symmetric tilt grain boundaries into YSTZ nanopillars, a decrease in strength and an increase in yield strain are observed.
||Planned: Supplemental Proceedings volume