FABRICATION, MICROSTRUCTURE, AND MECHANICAL-PROPERTIES OF CR2O3 ZRO2(2.5Y) COMPOSITE CERAMICS IN THE CR2O3-RICH REGION/

Intimate mixtures of Cr2O3ZrO2(2.5Y) in the Cr2O3-rich region are prod uced at low temperatures from amorphous materials prepared by the hydr azine method. Spark plasma sintering (SPS) has been performed for 10 m in at 1300 degrees C and 30 MPa. Composite ceramics with homogeneously dispersed fine ZrO2 (0.2 mu m) give 99.8% of theoretical densities. T heir mechanical properties are examined in connection with increased Z rO2 content. A high fracture toughness of 9.3 MPa.m(1/2) and an excell ent bending strength of 1290 MPa are achieved in the composite ceramic s containing 50 mol% ZrO2.