Densification of copper oxide doped alumina toughened zirconia by conventional sintering. Issue 5 (1st March 2022)

• Record Type: Journal Article
• Authors: Abbas, M.K.G.; Ramesh, S.; Sara Lee, K.Y.; Wong, Y.H.; Tan, C.Y.; Johnson Alengaram, U.; Ganesan, P.; Musharavati, Farayi; Zalnezhad, Erfan
• Is Part Of: Ceramics international. Volume 48:Issue 5(2022)
• Page Start: 6287
• Page End: 6293
• Publication Date: 2022-03-01
• Subjects: Alumina-toughened zirconia -- ATZ -- Copper oxide -- Sintering additive -- Conventional sintering; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.11.171
• Languages: English
• ISSNs: 0272-8842

Abstract

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% Al2 O3 ) ceramic composites was investigated. Green samples were pressureless sintered using a short hold time of 12 min at temperatures varying from 1250 °C to 1500 °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 °C, approximately 97% dense at 1350 °C and above 99% dense at 1450–1500 °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 °C/12 min. In comparison, the undoped composite exhibited relative densities of approximately 80% at 1250 °C, 87% at 1350 °C and approximately 97%–98% at 1450 °C-1500 °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.