Densification of copper oxide doped alumina toughened zirconia by conventional sintering
Document Type
Article
Publication Date
3-1-2022
Abstract
The effect of copper oxide doping (0.05-1 wt%) on the densification, microstructure evolution and mechanical characteristics of alumina toughened zirconia (ATZ: 80 wt% Y-TZP + 20 wt% Al2O3) ceramic composites was investigated. Green samples were pressureless sintered using a short hold time of 12 min at temperatures varying from 1250 degrees C to 1500 degrees C. The incorporation of up to 0.2 wt% copper oxide was beneficial in promoting densification at low sintering temperature and improving the mechanical properties of ATZ without affecting the tetragonal phase stability. It was found that 0.2 wt% copper oxide addition was most efficacious, and the samples could attain a relative density of approximately 92% at 1250 degrees C, approximately 97% dense at 1350 degrees C and above 99% dense at 1450-1500 degrees C. This approach was also accompanied by an improvement in the Vickers hardness (12.7 GPa) and fracture toughness (6.94 MPam(1/2)) when consolidated at 1450 degrees C/12 min. In comparison, the undoped composite exhibited relative densities of approximately 80% at 1250 degrees C, 87% at 1350 degrees C and approximately 97%-98% at 1450 degrees C-1500 degrees C. However, the study also found that higher dopant levels (0.5 wt% and 1 wt%) was not beneficial because the tetragonal zirconia phase was disrupted upon cooling from sintering, resulting in the monoclinic phase formation. In addition, low densification and poor mechanical properties were obtained.
Keywords
Alumina-toughened zirconia, ATZ, Copper oxide, Sintering additive, Conventional sintering
Divisions
mechanical
Funders
NPRP award from Qatar National Research Fund [NPRP11S-0102-180178]
Publication Title
Ceramics International
Volume
48
Issue
5
Publisher
Elsevier
Publisher Location
THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND