High temperature extrusion behavior of fine-grain ZrO2

Abstract

High temperature forming of a fine-grain ceramic is demonstrated by a series of extrusion experiments with fine-grain ZrO2, 3 mole% Y2O3. Piston velocities, ranging up to 5 mm/min (for a die with an initial diameter of 30 mm and a final diameter of 10 mm), can be achieved at 1500 °C with piston stresses of 70 MPa and graphite paper lubrication. These piston velocities are consistent with a calculation based on the creep behavior of this ceramic. The calculation is based on a model of material flow through the die, consistent with experiments involving internal markers of graphite foil.