On the t → m martensitic transformation in Ce-Y-TZP ceramics

The thermoelastic behavior and crystallography of the tetragonal (t) → monoclinic (m) martensitic transformation in Ce-Y-TZP ceramics are investigated by means of in situ transmission electron microscopy (TEM) and Wechsler-Lieberman-Read phenomenological theory. In situ TEM observations show that in Ce-Y-TZP the t/m interface can move freely with the change of thermal stress supplied by the beam illumination, whereas this is not found in thermal cycles. Based on the features of reversibility of interface motion, large thermal hysteresis and high critical driving force for Ce-Y-TZP, the t → m transformation is suggested as a semi-thermoelastic one. The habit plane and the lattice correspondence are determined as (1 3 0)_t and [0 0 1] _t//[0 1 0]_m, which is in agreement with the calculated results of the phenomenological theory.