Abstract
In this work, the static mechanical properties and cyclic fatigue life of 3 mol. (%) Y2O3-stabilized tetragonal zirconia polycrystalline (3Y-TZP) ceramics were investigated. Pre-sintered samples were sintered in air at 1600 °C for 120 minutes, and characterized by X ray diffraction and scanning electronic microscopy. Hardness and fracture toughness were determined by Vicker's indentation method, and Modulus of Rupture was determined by four-point bending testing. Fully dense sintered samples, near to 100% of theoretical density, presented hardness, fracture toughness and bending strength of 13.5 GPa, 8.2 MPa.m1/2 and 880 MPa, respectively. The cyclic fatigue tests were also realized using four-point bending testing, within a frequency of 25 Hz and stress ratio R of 0.1. The increasing of load stress lead to decreasing of the number of cycles and the run-out specimens number. The tetragonal-monoclinic (t-m) ZrO2-transformation observed by X ray diffraction contributes to the increasing of the fatigue life. The 3Y-TZP samples clearly presents a range of loading conditions where cyclic fatigue can be detected.
Highlights
Fatigue behavior which occurs below the critical failure strength is a common phenomenon in all materials including ceramics[1]
Dense 3Y-TZP ceramics were obtained after sintering at 1600 °C
Based on the high densification, refined microstructure composed of ZrO2 - grains with average size around 0.5 μm and high tetragonal phase content, this ceramic presented hardness, fracture toughness and bending strength of 13.5 GPa, 8.15 MPa.m1/2 and 880 MPa, respectively
Summary
Fatigue behavior which occurs below the critical failure strength is a common phenomenon in all materials including ceramics[1]. It is knowledge that ZrO2 additions may increase the fracture toughness of compatible ceramic materials. This effect is based on the tetragonal to monoclinic phase transformation of ZrO2, associated to the increasing of the grains around 3 and 5 vol (%)[9]. This volumetric expansion generates stresses in the ceramic matrix, which difficult the crack propagation. When this ceramic is used for implants such as artificial joints or dental abutment, it undergo loading for fairly long period[10]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call