2004 Volume 51 Issue 12 Pages 847-851
Solid-state electrochemical reduction was applied for yttria partially stabilized zirconia. The reduction was done by applying a DC voltage to the sample in a vacuum furnace at a temperature range from 400 to 700°C. The sample was reduced since oxygen is released at anode but oxygen is not supplied at cathode in vacuum. The reduced yttria partially stabilized zirconia changed the color to black, and the electric conductivity was increased. Apparent electric conductivity-quantity of electricity graph showed a crooked point. It was thought that the main part of electric conductivity changed form ionic to electronic at the point. Highly oxygen depleted yttria partially stabilized zirconia showed high electric conductivity even at room temperature. The Vickers hardness remained constant on electrochemical reduction, but the 3 points bending strength was degraded about 30% after the reduction.
