FABRICATION AND MECHANICAL-PROPERTIES OF CR2O3 SOLID-SOLUTION CERAMICS IN THE SYSTEM CR2O3-AL2O3

In the system Cr2O3-Al2O3, Cr2O3 solid solution (ss) powders containin g up to 25 mol% Al2O3 have been prepared by the hydrazine method. Dens e Cr2O3(ss) ceramics (99-99.2% of theoretical) have been fabricated by HIPing (1500 degrees C/2h/196MPa) of the compacts sealed under reduce d pressure. Their mechanical data are discussed, in comparison with th ose of Al2O3(SS) ceramics in this system. Microhardness (23.4 GPa) and fracture toughness (3.9 MPa.m(1/2)) are not dependent on the composit ions of Cr2O3(SS) ceramics. The former value is higher than that of mu ch improved Al2O3 (Al2O3(SS)) ceramics. Bending strength increases lin early with increasing Al2O3 content; the maximum value of 380 MPa is a chieved in the ceramics containing 25 mol% Al2O3. Copyright (C) 1997 E lsevier Science Ltd.