THE EFFECT OF TIO2 ADDITION ON STRENGTHENING AND TOUGHENING IN INTRAGRANULAR TYPE OF 12CE-TZP AL2O3 NANOCOMPOSITES/

To compensate the definite disadvantages of lower strength and lower h ardness in Ce-TZP, an intragranular type of 12Ce-TZP/0-30 vol% Al2O3 n anocomposite was investigated. Furthermore, the effect of TiO2 additio n on strengthening and toughening was also examined for the optimum co mponent of 30 vol% Al2O3, which showed a maximum strength of 866 MPa. For these composites, a novel interpenetrated intragranular microstruc ture was presented in which either 200-nm-sized Al2O3 particles or 30- 50-nm-sized ZrO2 particles were trapped, within the ZrO2 grains or Al2 O3 grains, respectively. The TiO2 was confirmed to dissolve into the t etragonal ZrO2 lattice, and contributed to the phase stability of the tetragonal phase and the promotion of intragranular nano-dispersion. F or the small amount (0.2 mol%) of TiO2 doped 12Ce-TZP/30 vol% Al2O3 co mposite, simultaneous improvements in strength (1012 MPa) and toughnes s (10.2 MPa.m(1/2) for the II; method, 5.7 MPa.m(1/2) for the SEVNB me thod) were achieved through tailoring the sintering condition. (C) 199 7 Elsevier Science Limited.