• Bonfante, Estevam A.
• Jalkh, Ernesto B. Benalcázar
• Genova, Luis A.
• Witek, Lukasz
• Gierthmuehlen, Petra C.
• Tebcherani, Sérgio M.
• Lopes, Adolfo C. O.
• Araújo-Júnior, Everardo N. S. De
• Bergamo, Edmara T. P.
• Coelho, Paulo
• Yamaguchi, Satoshi
• Campos, Tiago M. B.

Abstract

<p>To evaluate the effect of fatigue and aging on the crystalline content and reliability of a zirconia-toughened-alumina (ZTA) composite compared to its individual counterpart materials (3Y-TZP and Al₂O₃). Thirty-six disc-shaped specimens per group were obtained to comply with ISO 6872:2015. Crystalline content, microstructure and reliability of experimental groups were evaluated in four stages: 1) immediate; 2) aged; 3) fatigued; 4) aged + fatigue. Aging was performed in autoclave and Step-Stress-Accelerated-Life-Testing (SSALT) was performed using three stress profiles. Weibull statistics were used to determine Weibull parameters and life-expectancy. A significant increase in monoclinic phase in 3Y-TZP was observed after aging (19.31%), fatigue (17.88%) and aging + fatigue (55.81%), while ZTA evidenced minimal variation among all conditions (&lt;5.69%). 3Y-TZP presented higher reliability than ZTA at 300 and 500 MPa, and ZTA outperformed Al₂O₃ at the same stress missions. None of the ceramics yielded acceptable reliability at 800 MPa. A higher characteristic strength was observed for 3Y-TZP, followed by ZTA and Al₂O₃. While after aging ZTA and Al₂O₃ remained stable, 3Y-TZP exhibited a significant increase in the characteristic stress. Aging did not affect the reliability of ZTA and Al₂O₃. 3Y-TZP demonstrated an increase in monoclinic content and characteristic strength after aging.</p>

Topics

• microstructure
• phase
• strength
• fatigue
• composite
• aging
• ceramic
• aging