TOUGH AND STRONG CE-TZP ALUMINA NANOCOMPOSITES DOPED WITH TITANIA/

To develop a new attractive Ce-TZP ceramic, which possesses a high str ength while still preserving significant high toughness, we investigat ed an intragranular type of nanocomposite in lower CeO2 content for 0- 1 mol% TiO2 doped Ce-TZP/Al2O3 system. These composites partly possess ed an intragranular microstructure, in which several of 10-100 nm size d Al2O3 particles were trapped within the ZrO2 grains. Furthermore, el ongated Al2O3-like phases were produced at the ZrO2 grain boundaries, which were in-situ precipitated during the sintering process. TiO2 was confirmed to dissolve into the tetragonal ZrO2 lattice, which was det ermined to be effective for strengthening with a slight addition due t o its grain growth enhancing ability on ZrO2. For an optimum component with 0.05 mol% TiO2 doped 10Ce-TZP/30 vol% Al2O3 composite, both high strength (950 MPa) and high toughness (18.3 MPa.m(1/2) for the IF met hod, 9.8 MPa.m(1/2) for the SEVNB method) were achieved thus breaking through the strength-toughness tradeoff relation in transformation tou ghened ZrO2 and its composite materials. (C) 1998 Elsevier Science Lim ited and Techna S.r.l.