Fatigue behavior of 3%Y2O3-doped ZrO2 ceramics

Renato Chaves Souza, Claudinei dos Santos, Miguel Justino Ribeiro Barboza, Luiz de Araujo Bicalho, Carlos Antonio Reis Pereira Baptista, Carlos Nelson Elias
2014 Journal of Materials Research and Technology  
j m a t e r r e s t e c h n o l . 2 0 1 4;3(1):48-54 Available online at www.sciencedirect.com w w w . j m r t . c o m . b r Sintering Mechanical properties Fatigue Characterization Weibull probability a b s t r a c t The objective of this work was to evaluate the cyclic fatigue strength of a commercial pre-sintered tetragonal zirconia ceramics for dental systems, and to determine the main mechanical properties. Samples were sintered in air at 1600 • C for 120 min with heating and cooling rate
more » ... f 10 • C/min. The sintered specimens were characterized by X-ray diffraction and scanning electron microscopy. Hardness and fracture toughness were determined using the Vicker's indentation method. The strength was determined by four-point bending tests. The cyclic fatigue tests were realized as four-point bending tests within a frequency of 25 Hz and a stress ratio R of 0.1. The Weibull analysis was employed in order to perform failure probability calculations. Sintered specimens presented average values of hardness, fracture toughness and bending strength near to 13.5 GPa, 8 MPa m 1/2 and 900 MPa, respectively. The fatigue tests results allow concluding that the fatigue strength limit over 5 × 10 6 stress cycles is about 550 MPa or around 63% of the static strength of this material. The tetragonal-monoclinic (t-m) zirconia transformation observed by X-ray diffraction of fractured surfaces occurs during cyclic loading and the fracture of specimens. The 3Y-TZP samples clearly present a range of loading conditions where cyclic fatigue can be detected. The fatigue strength limit around 550 MPa is appropriate for application in dental implant parts.
doi:10.1016/j.jmrt.2013.10.005 fatcat:boy52uycrjhctb4efej3k3nigm