Yttria Ceria Co-Stabilized Zirconia Reinforced with Alumina and Strontium Hexaaluminate

Abstract

Zirconia materials are frequently used in dental applications due to their excellent strength and their tooth-like aspect. Standard yttria stabilized zirconia (Y-TZP) ceramics suffer, however, from moderate toughness and vulnerability to low-temperature degradation. In this study, 1Y6Ce-TZP materials reinforced with different amounts of alumina and/or strontium hexaaluminate were manufactured by slip casting and pressureless sintering at different temperatures to assess their mechanical properties, microstructure, phase composition, and low-temperature degradation stability. Results show that these materials exhibit a high fracture resistance of 10–12 MPa√m, a bending strength between 700–950 MPa, and a Vickers hardness of 1100–1200 HV10. Strontium hexaaluminate (SA6) precipitates were formed in situ by reaction of alumina and strontium zirconate. Although crack deflection at SA6 platelets was clearly visible, a net toughening was not observed. Accelerated ageing tests at 134 °C/3 bar water vapor pressure showed best results for mixed alumina/SA6 reinforcements and a sintering temperature of 1500 °C. Mehl-Avrami-Johnson plots used to describe the ageing kinetics showed clear indications of different ageing mechanisms due to the introduction of the SA6 phase.

Ceramic Toughening Strategies for Biomedical Applications

“…They thought several different toughening mechanisms acting simultaneously in the material. Apart from the above ingredients of Santos et al’s study, Gommeringer et al (2019) reinforced 1Y6Ce-TZP materials with different amounts of alumina and/or strontium hexaalumina by slip casting and pressureless sintering at different temperatures. Then these materials underwent accession of their mechanical properties, microstructure, phase composition, and low-temperature degradation stability, which showed that they exhibited a high fracture resistance of 10–12 MPa m 1/2 .…”

Bruxismo Durante O Sono

“…O aditivo óxido de cério (IV) vem sendo estudado para redução das vacâncias de oxigênio pelo fato de ser tetravalente (Ce 4+ ) semelhante a zircônia e em quantidades apropriadas (cerca de 10-10,5% em mol) foi responsável pelo aumento da tenacidade à fratura para valores entre 10-12 MPa.m 1/2 , atuando na redução das vacâncias de oxigênio é possível reduzir o efeito da LTD (GOMMERINGER et al, 2019).…”

Effect of gadolinia addition on the mechanical and physical properties of zirconia/ceria ceramics

“…Additives used to stabilize zirconia not only produce crack-free zirconia, but also the sintered compact can retain the high temperature phase, i.e., the tetragonal phase at room temperature, where the equilibrium phase is monoclinic [1,2]. Among all zirconia ceramics, yttria tetragonal zirconia polycrystals (YTZPs) are the most attractive, for wide range of energy and biomedical applications, due to their unusual combination of excellent mechanical properties (i.e., high strength and high fracture toughness), as well as low thermal conductivity and biocompatibility [3][4][5][6][7][8][9][10].…”