Effect of the sintering parameters on the structure and mechanical properties of zirconia-based ceramics

The paper presents the results of an investigations of the sintered zirconia ceramics that have been stabilized with Y2O3 2 O 3 and CeO2. 2 . The initial powders were synthesized via decomposition of the fluoride salts, which determined morphological features and dimensions of the particles. The specific electroconsolidation process, performed using the modified spark plasma sintering device, allowed for the retention of the nanoscale grain sizes and related properties of the sintered ceramic composites. It was found that the as-obtained materials with cerium oxide exhibited high bending strength of 609 MPa, by ca. 33 % higher than that of yttria-stabilized ones (410 MPa). In turn, the best combination of hardness and fracture toughness, K 1 & Scy; = 5.8 & Mcy; P & acy;& sdot; m 1/2 & acy; nd & Ncy; v = 14.8 GP & acy;, & acy;, respectively, exhibited ZrO2+3 2 +3 wt% Y2O3. 2 O 3 . This result can be attributed to the chemical composition and morphology of the powders, which in turn is influenced by the synthesis conditions and calcination time and temperatures, as well as to the sintering parameters. In particular, yttria-stabilized zirconia showed higher sensitivity to the variations of the sintering temperatures and holding times.