Additive effect of micro-damage zones from nano-scale crack tip and nano-grains for fracture toughness measurements of 3Y-TZP zirconia ceramics. Issue 15 (December 2022)

• Record Type: Journal Article
• Authors: Hu, Xiaozhi
• Is Part Of: Journal of the European Ceramic Society. Volume 42:Issue 15(2022)
• Page Start: 7174
• Page End: 7179
• Publication Date: 2022-12
• Subjects: Ceramics -- Fracture mechanism -- Microcracking -- Nanocrystalline microstructure -- Strength and toughness relation; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2022.08.017
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: A nano-scale crack tip around 500 nm wide introduced by femtosecond laser still affects the accuracy of fracture toughness K IC measurements of 3Y-TZP zirconia ceramics with average grain size G from 200 to 500 nm. A simple formula was proposed to estimate the additive effect of crack-tip damage zones from an infinitely sharp crack to a nano-scale blunt notch. The error in fracture toughness measurements is less than 8 % if the nano-scale crack-tip width < 0.5· G . The intrinsic K IC can be deduced from the simple formula if the nano-scale crack tip > 0.5· G . This study shows the same K IC was deduced from two different sets of 3Y-TZP measurements with nano- and micro-scale notches of 500 nm and 18 µm wide. Furthermore, the simple formula specifies the relation between the fracture toughness K IC and intrinsic strength f t via grain size G, which means K IC can also be estimated from f t and G without testing pre-cracked specimens. K IC values of 3Y-TZP from specimens with and without pre-cracks were compared.