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Fatigue and damage tolerance of Y‐TZP ceramics in layered biomechanical systems
Author(s) -
Zhang Yu,
Pajares Antonia,
Lawn Brian R.
Publication year - 2004
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.30083
Subject(s) - materials science , ceramic , cyclic stress , composite material , flexural strength , fracture (geology) , mechanical failure , bilayer , surgery , membrane , biology , genetics , medicine
The fatigue properties of fine‐grain Y‐TZP in cyclic flexural testing are studied. Comparative tests on a coarser‐grain alumina provide a baseline control. A bilayer configuration with ceramic plates bonded to a compliant polymeric substrate and loaded with concentrated forces at the top surfaces, simulating basic layer structures in dental crowns and hip replacement prostheses, is used as a basic test specimen. Critical times to initiate radial crack failure at the ceramic undersurfaces at prescribed maximum surface loads are measured for Y‐TZP with as‐polished surfaces, mechanically predamaged undersurfaces, and after a thermal aging treatment. No differences in critical failure conditions are observed between monotonic and cyclic loading on as‐polished surfaces, or between as‐polished and mechanically damaged surfaces in monotonic loading, consistent with fatigue controlled by slow crack growth. However, the data for mechanically damaged and aged specimens show substantial declines in sustainable stresses and times to failure in cyclic loading, indicating an augmenting role of mechanical and thermal processes in certain instances. In all cases, however, the sustainable stresses in the Y‐TZP remain higher than that of the alumina, suggesting that with proper measures to avoid inherent structural instabilities, Y‐TZP could provide superior performance in biomechanical applications. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 166–171, 2004