Fatigue Behavior of GeO2-SiO2 Glasses

1998 ◽  
Vol 531 ◽  
Author(s):  
Suresh T. Gulati ◽  
John D. Helfinstine

AbstractThe fatigue behavior of binary oxide glasses in the germania-silica system is interesting since it influences the long-term mechanical reliability of products made of these glasses. Dynamic fatigue tests were carried out in four-point bending in 100% RH using tumble abraded rods. The fatigue data were obtained as a function of GeO2 content which ranged from 0 to 24 mole %. In addition, other physical properties of these glasses, such as the thermal expansion coefficient, were measured as a function of GeO2 content. The results of these tests and analyses are highlighted in this paper.

2016 ◽  
Vol 35 (3) ◽  
pp. 225-234 ◽  
Author(s):  
Hasan Kaya ◽  
Mehmet Uçar

AbstractIn this study, the effects of equal channel angular pressing (ECAP) on high-cycle fatigue and fatigue surface morphology of AA7075 have been investigated at a constant temperature (483 K) and the “C” route for four passes at ECAP process. ECAPed and as-received specimens were tested by four-point bending fatigue device. Fatigue tests were carried out by using 100, 120 and 140 MPa strength values. ECAPed specimens were characterized for each pass with optical microscope (OM), scanning electron microscope (SEM), energy-dispersive spectroscope (EDS), transmission electron microscope (TEM), selected area electron diffraction (SAED) and hardness measurements. Fracture surfaces of the specimens were also characterized with SEM. The results show that the highest hardness values (137 HV) and the best fatigue life (5.4 × 107for 100 MPa) were measured in ECAPed four-pass sample. For this reason hardness values and fatigue life were increased with increasing number of severe plastic deformation (SPD) process.


1994 ◽  
Vol 116 (1) ◽  
pp. 54-61 ◽  
Author(s):  
T. H. Krukemyer ◽  
A. Fatemi ◽  
R. W. Swindeman

An experimental investigation was conducted on Haynes Alloy 556 to study the fatigue behavior of the material at elevated temperatures. Fatigue tests were run at constant temperatures ranging from room temperature to 871°C with strain ranges from 0.265 to 1.5 percent resulting in lives between 102 and 106 cycles. Cyclic deformation properties were evaluated based on the fatigue data. Three fatigue life models were evaluated for their ability to predict the isothermal fatigue lives of the material. These included the Ostergren, Frequency Separation and Stress-Strain-Time models. Strengths and weaknesses of each model are discussed based on the experimental results.


2005 ◽  
Vol 903 ◽  
Author(s):  
F. X. Liu ◽  
C. L. Chiang ◽  
J. P. Chu ◽  
Y. F. Gao ◽  
P. K. Liaw

AbstractGlass-forming Zr47Cu31Al13Ni9 (in atomic percent) films of various thicknesses were deposited on the C-2000 Ni-based alloy substrate by magnetron sputtering. Four-point-bending fatigue tests were conducted on the above system with the coated surface on the tensile side. It has been found that both fatigue life and fatigue-endurance limit can be considerably improved, while the degree of fatigue resistance enhancement depends on the maximum applied stress and the film thickness. Mechanisms of fatigue-resistance enhancements of the coated Ni-based alloy are discussed from the following aspects: reduction of surface roughness by the thin-film coating, good adhesion between thin film and substrate, development of residual compressive stress, and excellent ductility of glass-forming thin film (which would be otherwise brittle in bulk form). Of particular interest, we examine the interaction of substrate slip bands and the thin film ductile property, which would delay fatigue crack initiation process and thus extend the fatigue life.


1992 ◽  
Vol 287 ◽  
Author(s):  
Yasuhiro Shigegaki ◽  
Takashi Inamura ◽  
Akihiko Suzuki ◽  
Tadashi Sasa

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.


Author(s):  
Diego F. S. Burgos ◽  
Luís F. S. Parise ◽  
Rafael G. Savioli ◽  
Gustavo H. B. Donato ◽  
Antonio P. Nascimento Filho ◽  
...  

This work presents an experimental investigation of the effects of plastic strain on the fatigue behavior of superduplex steel tubes. Fatigue tests using conventional axial loading and a resonant bending setup conducted on 15mm OD tubes made of SAF2507 superduplex steel provides S × N data upon which effects of different levels of plastic strain can be assessed. Despite the inherent scatter in the measured fatigue data, the experiments reveal consistent trends and relatively small effects of plastic strain on fatigue behavior of superduplex steel tubes.


2009 ◽  
Vol 51 (9) ◽  
pp. 580-586 ◽  
Author(s):  
Bernd Oberwinkler ◽  
Martin Riedler ◽  
Heinz Leitner ◽  
Ataollah Javidi

Alloy Digest ◽  
1987 ◽  
Vol 36 (8) ◽  

Abstract NILO alloy 36 is a binary iron-nickel alloy having a very low and essentially constant coefficient of thermal expansion at atmospheric temperatures. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Fe-79. Producer or source: Inco Alloys International Inc..


Alloy Digest ◽  
1971 ◽  
Vol 20 (1) ◽  

Abstract UNISPAN LR35 offers the lowest coefficient of thermal expansion of any alloy now available. It is a low residual modification of UNISPAN 36 for fully achieving the demanding operational level of precision equipment. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and surface treatment. Filing Code: Fe-46. Producer or source: Cyclops Corporation.


Alloy Digest ◽  
1998 ◽  
Vol 47 (4) ◽  

Abstract Deltalloy 4032 has good machinability and drilling characteristics when using single-point or multispindle screw machines and an excellent surface finish using polycrystalline or carbide tooling. The alloy demonstrates superior wear resistance and may eliminate the need for hard coat anodizing. Deltalloy 4032 is characterized by high strength and a low coefficient of thermal expansion. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion and wear resistance as well as machining and surface treatment. Filing Code: AL-347. Producer or source: ALCOA Wire, Rod & Bar Division.


Alloy Digest ◽  
1960 ◽  
Vol 9 (2) ◽  

Abstract RED X-20 is a heat treatable hypereutectic aluminum-silicon alloy with excellent wear resistance and a very low coefficient of thermal expansion. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-89. Producer or source: Apex Smelting Company.


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