Dynamic Fatigue of Y-TZP Ceramics at the Room Temperature

2007 ◽  
Vol 336-338 ◽  
pp. 2429-2431 ◽  
Author(s):  
Chun Guang Li ◽  
Wen Jie Si ◽  
Wei Fang Zhang

Dynamic fatigue behavior of two kinds of Y-TZP ceramics was investigated at room temperature. The results showed that dynamic fatigue and slow crack growth behaviors exist in zirconias. Crack growth exponents of original and pre-cracked samples were obtained. Crack growth exponents of the two original zirconias are 15.60 and 21.00, respectively. Crack growth exponents of annealed pre-cracked samples are close to the original samples, indicating that the pre-crack experimental method is reasonable and effective. Because of the influence of residual stress indcued by indentation, crack growth exponents of unannealed samples are different from that of original samples. So residual stress should be removed.

1992 ◽  
Vol 287 ◽  
Author(s):  
Chih-Kuang Jack Lin ◽  
Michael G. Jenkins ◽  
Matitison K. Ferber

ABSTRACTTensile fatigue behavior of a hot-isostatically-pressed (HIPed) silicon nitride was investigated over ranges of constant stresses, constant stress rates, and cyclic loading at 1150-1370°C. At 1150°C, static and dynamic fatigue failures were governed by a slow crack growth mechanism. Creep rupture was the dominant failure mechanism in static fatigue at 1260 and 1370°C. A transition of failure mechanism from slow crack growth to creep rupture appeared at stress rates ≤10−2 MPa/s for dynamic fatigue at 1260 and 1370°C. At 1 150-1370°C, cyclic loading appeared to be less damaging than static loading as cyclic fatigue specimens displayed greater failure times than static fatigue specimens under the same maximum stresses.


1991 ◽  
Vol 26 (23) ◽  
pp. 6467-6472 ◽  
Author(s):  
K. R. McKinney ◽  
B. A. Bender ◽  
R. W. Rice ◽  
C. Cm. Wu

Author(s):  
Sung R. Choi ◽  
D. Calvin Faucett ◽  
Brenna Skelley

An extensive experimental work for Pyroceram™ 9606 glass-ceramic was conducted to determine static fatigue at ambient temperature in distilled water. This work was an extension and companion of the previous work conducted in dynamic fatigue. Four different applied stresses ranging from 120 to 170 MPa was incorporated with a total of 20–23 test specimens used at each of four applied stresses. The slow crack growth parameters n and D were found to be n = 19 and D = 45 with a coefficient of correlation of rcoef = 0.9653. The Weibull modulus of time to failure was in a range of msf = 1.6 to 1.9 with an average of msf = 1.7±0.2. A life prediction using the previously-determined dynamic fatigue data was in excellent agreement with the static fatigue data. The life prediction approach was also applied to advanced monolithic ceramics and ceramic matrix composites based on their dynamic and static fatigue data determined at elevated temperatures. All of these results indicated that a SCG mechanism governed by a power-law crack-growth formulation was operative, a commonality of slow crack growth in these materials systems.


1984 ◽  
Vol 106 (1) ◽  
pp. 25-37 ◽  
Author(s):  
R. I. Stephens ◽  
J. H. Chung ◽  
A. Fatemi ◽  
H. W. Lee ◽  
S. G. Lee ◽  
...  

A comprehensive fatigue program was undertaken at room temperature and −45°C (−50°F) for five representative carbon or low alloy cast steels. Constant amplitude low and high cycle axial fatigue behavior, cyclic stress-strain behavior, constant-amplitude fatigue-crack-growth behavior and variable-amplitude fatigue-crack-initiation and -growth behavior were determined. The fatigue resistance at low temperature was usually equal to or better than at room temperature except for one material under variable amplitude fatigue crack growth conditions. SEM analysis revealed similar fatigue crack growth mechanisms at both room and low temperature, even though some tests were well below the NDT temperature. Most fatigue resistance for the five cast steels was consistent with that for wrought steels. Fatigue test procedures generally developed with wrought steels were completely satisfactory for these cast steels.


Author(s):  
Sung R. Choi ◽  
D. Calvin Faucett ◽  
Brenna Skelley

An extensive experimental work for Pyroceram™ 9606 glass–ceramic was conducted to determine static fatigue at ambient temperature in distilled water. This work was an extension and companion of the previous work conducted in dynamic fatigue. Four different applied stresses ranging from 120 to 170 MPa was incorporated with a total of 20–23 test specimens used at each of four applied stresses. The slow crack growth (SCG) parameters n and D were found to be n = 19 and D = 45 with a coefficient of correlation of rcoef = 0.9653. The Weibull modulus of time to failure was in a range of msf = 1.6–1.9 with an average of msf = 1.7 ± 0.2. A life prediction using the previously determined dynamic fatigue data was in excellent agreement with the static fatigue data. The life prediction approach was also applied to advanced monolithic ceramics and ceramic matrix composites (CMCs) based on their dynamic and static fatigue data determined at elevated temperatures. All of these results indicated that a SCG mechanism governed by a power-law crack growth formulation was operative, a commonality of SCG in these materials systems.


1988 ◽  
Vol 96 (1117) ◽  
pp. 885-889 ◽  
Author(s):  
Yukihiko YAMAUCHI ◽  
Seisuke SAKAI ◽  
Masaru ITO ◽  
Tatsuki OHJI ◽  
Wataru KANEMATSU ◽  
...  

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