Defect-induced asymmetrical mechanical behavior in shape memory zirconia: A phase-field investigation

An elastoplastic phase-field model is used to investigate the deformation mechanisms of yttria stabilized tetragonal zirconia in presence defects. A remarkable tension-compression asymmetry detected. higher strength and a lower degree transformation are observed compression than tension. Also, mechanism asymmetric depending on crystal orientation. For some cases (other cases), phase absent tension (in compression), while both plasticity present tension). Such attributed activation different monoclinic variants with Eigen strain tensors versus compression. Results also reveal onset stresses as void size increases. Elliptic voids exhibit directional effect maximum stress intensity factor 5.6 MPa m1/2 when long semi-axis diagonally oriented respect loading direction, this prediction comparable experiments.