Athermal effect of flash event on high-temperature plastic deformation in Y2O3-stabilized tetragonal ZrO2 polycrystal
Hiroki Motomura, Daiki Tamao, Kohta Nambu, Hiroshi Masuda, Hidehiro Yoshida
Abstract
This study experimentally demonstrates the athermal effect of a flash event under a DC electric field on high-temperature plastic deformation in a dense, fine-grained 3 mol% Y2O3-stabilized tetragonal ZrO2 polycrystal (3Y-TZP). A high-temperature three-point flexural test in the conventionally sintered 3Y-TZP body with an average grain size of 0.36 µm was conducted under a flash event with a current density of 67 mA·mm−2 at a furnace temperature between 900 °C and 1300 °C. The flash event significantly enhanced the high-temperature plastic flow in the 3Y-TZP body, even though subtracting the effect of specimen temperature rise by Joule heating, while grain growth during the flexural tests was effectively suppressed under the examined conditions. The athermal effect on the plastic flow was attributed to the reduction in the activation energy for the high-temperature plastic flow.