A critical note on nanoscale plasticity in 20 ZTA ceramics

The present work reports the very first observations on initiation of nanoscale plastic events in 20 ZTA (Zirconia Toughened Alumina) ceramics. The nanomechanical properties as well as the intrinsic contact deformation resistance of the present ZTA ceramic are studied here as a function of low loads (i.e., 10–1000 mN). Here we report for the very first time, the detailed mechanisms on the genesis of ‘micro pop-in’ events that characterize the nanoscale plasticity initiation in the 20 ZTA ceramics. These new results along with field emission scanning electron microscopy (FESEM) based evidences confirm that the combined contributions from the maximum shear stress generated underneath the nanoindenter, the formations of shear bands and localized microcracking play significant roles in the initiation of nanoscale plastic events in the 20 ZTA ceramics.