Evaluation of Tensile Static, Dynamic, and Cyclic Fatigue Behavior for A Hiped Silicon Nitride at Elevated Temperatures

1992 ◽  
Vol 287 ◽  
Author(s):  
Chih-Kuang Jack Lin ◽  
Michael G. Jenkins ◽  
Matitison K. Ferber
Keyword(s):  
Silicon Nitride ◽  
Cyclic Loading ◽  
Crack Growth ◽  
Failure Mechanism ◽  
Fatigue Behavior ◽  
Slow Crack Growth ◽  
Cyclic Fatigue ◽  
Creep Rupture ◽  
Static Fatigue ◽  
Dynamic Fatigue

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.

Slow Crack Growth of a Pyroceram Glass Ceramic Under Static Fatigue Loading: Commonality of Slow Crack Growth in Advanced Ceramics

2014 ◽  
Author(s):  
Sung R. Choi ◽  
D. Calvin Faucett ◽  
Brenna Skelley
Keyword(s):  
Crack Growth ◽  
Glass Ceramic ◽  
Life Prediction ◽  
Elevated Temperatures ◽  
Slow Crack Growth ◽  
Static Fatigue ◽  
Fatigue Data ◽  
Prediction Approach ◽  
Applied Stresses ◽  
Dynamic Fatigue

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.

Slow Crack Growth of a Pyroceram Glass Ceramic Under Static Fatigue Loading—Commonality of Slow Crack Growth in Advanced Ceramics

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Sung R. Choi ◽  
D. Calvin Faucett ◽  
Brenna Skelley
Keyword(s):  
Crack Growth ◽  
Glass Ceramic ◽  
Life Prediction ◽  
Elevated Temperatures ◽  
Slow Crack Growth ◽  
Static Fatigue ◽  
Fatigue Data ◽  
Prediction Approach ◽  
Applied Stresses ◽  
Dynamic Fatigue

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.

Adhesion and Reliability of Epoxy/Glass Interfaces

2000 ◽  
Vol 123 (4) ◽  
pp. 401-404 ◽  
Author(s):  
John E. Ritter ◽  
Armin Huseinovic
Keyword(s):  
Fatigue Crack ◽  
Cyclic Loading ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Slow Crack Growth ◽  
Cyclic Fatigue ◽  
Aqueous Environments ◽  
Crack Tip Plasticity ◽  
Static And Cyclic Loading ◽  
Microelectronic Components

The reliability of microelectronic components is profoundly influenced by the fracture resistance of the polymer/inorganic interfaces and by the progressive debonding of these interfaces in aqueous environments. Consequently, fatigue (slow) crack growth in epoxy/glass interfaces bonded with the silane coupling agent 3-aminopropyltriethoxysilane (3-APES) was studied under static and cyclic loading at 23°C and in either dry or humid conditions using the double cleavage drilled compression (DCDC) test. Crack growth rates under cyclic loading were significantly greater than under static loading, indicating that stress corrosion effects are negligible and that crack tip plasticity controls cyclic fatigue crack growth at silane (3-APES) bonded epoxy/glass interfaces. After aging at 94°C in water, these silane bonded epoxy/glass interfaces exhibited somewhat greater resistance to cyclic fatigue crack growth than the unaged samples; however, after aging at 98°C in water cyclic fatigue crack growth became cohesive and fractal in nature. Mechanisms for fatigue crack growth at silane (3-APES) bonded epoxy/glass interfaces are discussed.

High Temperature Fatigue Properties of Silicon Nitride in Nitrogen Atmosphere

1992 ◽  
Vol 287 ◽  
Author(s):  
Yasuhiro Shigegaki ◽  
Takashi Inamura ◽  
Akihiko Suzuki ◽  
Tadashi Sasa
Keyword(s):  
Silicon Nitride ◽  
Fatigue Behavior ◽  
Cyclic Fatigue ◽  
Nitrogen Atmosphere ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Static Fatigue ◽  
Four Point Bending ◽  
Bending Mode ◽  
Sintered Silicon

ABSTRACTCyclic and static fatigue properties of pressure-less sintered silicon nitride were evaluated at 1000° C in air and in nitrogen using four-point bending mode. The data of cyclic fatigue tests or static fatigue tests and the morphology of the fractured surfaces in nitrogen were compared with those in air. The cyclic fatigue behavior was remarkably influenced by the atmosphere, while the static fatigue was less influenced. Crack healing effect due to the oxidation around the crack are thought to be the most probable mechanism to affect the cyclic fatigue rate in air.

Slow Crack Growth and Creep Rupture of Ba0.5Sr0.5Co0.8Fe0.2O3 – δ

2011 ◽  
Vol 488-489 ◽  
pp. 303-306
Author(s):  
Jürgen Malzbender ◽  
G. Pećanac ◽  
Stefan Baumann
Keyword(s):  
Crack Growth ◽  
Room Temperature ◽  
Slow Crack Growth ◽  
Creep Rupture ◽  
Transient Temperature ◽  
Static Fatigue ◽  
Operation Temperature ◽  
Separation Membrane ◽  
Application Potential ◽  
Temperature Exposure

Ba0.5Sr0.5Co0.8Fe0.2O3 – δ is a mixed ion-electron conductor with high application potential as high-temperature gas separation membrane. However, in practical use the integrity of this brittle perovskite is challenged by the mechanical boundary conditions of transient temperature exposure. Moreover, long term failure mechanisms such as static fatigue at room temperature and creep rupture at operation temperature might occur. The relevance of both effects for BSCF has been investigated. The slow crack growth at room temperature has been determined using bi-axial bending under different loading rates. The creep rupture at elevated temperature has been analyzed from three-point bending tests. The results indicate favourable behaviour of BSCF in both cases. A low risk of failure due to slow crack growth exists and the strain to failure in combined tensile - compressive mode reaches up to 40 %.

scholarly journals Static Fatigue of SiC/SiC Minicomposites at High Temperatures up to 1200 °C in Air: Multiscale Approach

2021 ◽  
Vol 5 (3) ◽  
pp. 67
Author(s):  
Jacques Lamon ◽  
Adrien Laforêt
Keyword(s):  
Crack Growth ◽  
High Temperatures ◽  
Fatigue Behavior ◽  
Slow Crack Growth ◽  
Stress Rupture ◽  
Rupture Time ◽  
Cumulative Distribution ◽  
Initial Stresses ◽  
Static Fatigue ◽  
Time Relation

The present paper investigates the static fatigue behavior of Hi-Nicalon fiber-reinforced SiC–SiC minicomposites at high temperatures in the 900–1200 °C range, and under tensile stresses above the proportional limit. The stress–rupture time relation was analyzed with respect to subcritical crack growth in filaments and fiber tow fracture. Slow crack growth from flaws located at the surface of filaments is driven by the oxidation of free carbon at the grain boundaries. Lifetime of the reinforcing tows depends on the statistical distribution of filament strength and on structural factors, which are enhanced by temperature increase. The rupture time data were plotted in terms of initial stresses on reinforcing filaments. The effect of temperature and load on the stress–rupture time relation for minicomposites was investigated using results of fractography and predictions of minicomposite lifetime using a model of subcritical growth for critical filaments. The critical filament is the one whose failure by slow crack-growth triggers unstable fracture of the minicomposite. This is identified by the strength–probability relation provided by the cumulative distribution function for filament strength at room temperature. The results were compared to the fatigue behavior of dry tows. The influence of various factors related to oxidation, including multiple failures, load sharing, and variability, was analyzed.

Performance of CVD Mullite Coatings on Silicon Nitride under High Temperature High Load Conditions

2005 ◽  
Vol 287 ◽  
pp. 457-470 ◽  
Author(s):  
S.M. Zemskova ◽  
Hua Tay Lin ◽  
Mattison K. Ferber ◽  
A.J. Haynes
Keyword(s):  
Silicon Nitride ◽  
Slow Crack Growth ◽  
Ambient Air ◽  
Fatigue Tests ◽  
Static Fatigue ◽  
Strength Increase ◽  
Test Procedures ◽  
Flexure Strength ◽  
Mullite Coatings ◽  
Dynamic Fatigue

Previous studies have demonstrated that dense coatings of CVD mullite (3Al2O3×2SiO2) provide excellent oxidation protection for Si3N4 and SiC in a high pressure, steam environment. In this study the mechanical properties of CVD mullite coated silicon nitride materials from different vendors (AS800, NGKSN88, Kyocera SN281) were evaluated following ASTM test procedures. The dynamic fatigue tests werep erformed in ambient air at temperatures of 850 and 1200°C under fast (30 MPa/s) and slow (0.003 MPa/s) load rates. The static fatigue tests were carried out at a constant load of 350 MPa for 1000h at 1200°C. The cyclic fatiguetests at 850°C consisted of a loading ramp from 20 to 400 MPa in 30 seconds followed by unloading ramp from 400 to 20 MPa. A total of 10,000 cycles were applied to the fatigue test specimens before fast fracture tests were conducted at room temperature. The strength test results indicated that CVD mullite coatings showed excellent adhesion during dynamic fatigue tests and exhibited no creep behavior. Minor flexure strength reduction observed at low stressing rate and at high temperatures appeared to be related to Si3N4 properties such as SCG (slow crack growth) susceptibility. During cyclic and static fatigue tests, a glassy silica/aluminosilicate phase was formed due to oxidation. This resulted in localized coating separation and buckling. However, accumulation of this corrosion layer was not critical since the coated specimens showed a flexure strength increase of ~7-9.5%.

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
Keyword(s):  
Residual Stress ◽  
Experimental Method ◽  
Crack Growth ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Slow Crack Growth ◽  
Indentation Crack ◽  
Dynamic Fatigue

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.

Examination of Fracture Interfaces in Silicon Nitride

1975 ◽  
Vol 33 ◽  
pp. 60-61
Author(s):  
Nancy J. Tighe
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Slow Crack Growth ◽  
Ceramic Materials ◽  
Grain Boundary Sliding ◽  
Boundary Phase ◽  
Turbine Engines ◽  
Boundary Sliding

Silicon nitride is one of the ceramic materials being considered for the components in gas turbine engines which will be exposed to temperatures of 1000 to 1400°C. Test specimens from hot-pressed billets exhibit flexural strengths of approximately 50 MN/m2 at 1000°C. However, the strength degrades rapidly to less than 20 MN/m2 at 1400°C. The strength degradition is attributed to subcritical crack growth phenomena evidenced by a stress rate dependence of the flexural strength and the stress intensity factor. This phenomena is termed slow crack growth and is associated with the onset of plastic deformation at the crack tip. Lange attributed the subcritical crack growth tb a glassy silicate grain boundary phase which decreased in viscosity with increased temperature and permitted a form of grain boundary sliding to occur.

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