Cold isostatic pressing as a method for fabricating high-strength ceramic materials based on ZrO2

Abstract

High-strength ceramic materials fabricated with the use of cold isostatic pressing (CIP) at ≤0.8 GPa and sintering by different regimes from yttria-stabilized zirconia produced by leading foreign and Ukrainian firms are described. All the materials exhibit two peaks of mechanical properties, one at a low CIP pressure (0.1–0.3 GPa) attributable to destabilization of the press-powder and characterizing the stability of the material as a whole and the other at a high CIP pressure (above 0.6 GPa) attributable to attainment of close packing of the particles. In accordance with the set of standard properties the materials can be classified into two types, namely, intermediate-strength ones with an ultimate bending strength of 700–900 MPa,K1c ranging from 7 to 12 MPa·m1/2, a density of about 6 g/cm2, and an optimum CIP pressure of 0.2–0.3 GPa (the first peak) and high-strength materials with an ultimate bending strength of about 1200 MPa,KIc ranging from 6 to 9 MPa·m1/2, a density of about 6.1 g/cm3, and an optimum CIP pressure of 0.1 GPa. The intermediate type comprises the majority of domestic materials and some foreign ones and is characterized by higher stability and crack resistance. The high-strength type comprises mainly foreign materials with high strength and lower stability.