Corrosion Fatigue Tests of Micro-Sized Specimens

2000 ◽  
Vol 657 ◽  
Author(s):  
Y. Mizutani ◽  
Y. Higo ◽  
Y. Ichikawa ◽  
A. Morita ◽  
K. Takashima ◽  
...  
Keyword(s):  
Fatigue Test ◽  
Corrosion Fatigue ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Fatigue Tests ◽  
Test Method ◽  
Fatigue Properties ◽  
Mems Devices ◽  
Problems And Solutions ◽  
Beam Type

ABSTRACTCorrosion fatigue properties of micro-sized materials are extremely important to design MEMS devices and micro-machines used in corrosive environments. However, there have been few studies that investigate corrosion fatigue properties of micro-sized materials. Thus, it is necessary to develop a corrosion fatigue test method for micro-sized materials. However, there are several difficulties in corrosion fatigue tests on micro-sized specimens. It is also necessary to clarify the problems for the method and to find their solutions. In this investigation, a corrosion fatigue test method for micro-sized specimens has been developed and corrosion fatigue tests for micro-sized Ni-P amorphous alloy specimens have been carried out in a 0.9% NaCl solution. Specimens of cantilever-beam-type with dimensions of 10 × 12 × 50 μm3 were prepared from a Ni-P amorphous thin film by focused ion beam machining. Corrosion fatigue tests on the micro-sized specimens were succeeded, and environmental effects on fatigue properties of micro-sized specimens were clearly observed. Several problems and solutions for the method were described.

Fatigue Testing Machine of Micro-Sized Specimens for MEMS Applications

1999 ◽  
Vol 605 ◽  
Author(s):  
Y. Higo ◽  
K. Takashima ◽  
M. Shimojo ◽  
S. Sugiura ◽  
B. Pfister ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Fatigue Testing ◽  
Ion Beam ◽  
Testing Machine ◽  
Load Cell ◽  
Fatigue Properties ◽  
Type Specimens ◽  
New Type ◽  
Beam Type ◽  
Magnetostrictive Actuator

AbstractA new type of fatigue testing machine for micro-sized specimens for MEMS applications has been developed. This fatigue testing machine consists of a magnetostrictive actuator which is able to impart small displacements to a specimen upto 20 νm with resolution of 5 nm. The actuator is connected to a metal shaft and a diamond tip of 5 νm in radius is attached to the end of the shaft. Small displacements are applied to the specimen through the diamond tip. This makes it possible to construct a high stiffness loading fixture. The magnitude of load applied to the specimen is measured by a strain gauge type load cell with a load resolution of 10 νN. The specimen stage and load cell can be moved to adjust the loading position precisely by a stepping motor at a translation resolution of 0.1 νm. Cantilever beam type specimens with dimensions of 10 × 12 × 50 νm3 were prepared from a Ni-P amorphous thin film by focused ion beam machining. Very small cyclic load (ΔP = 0.1 - 40 mN) was able to be applied to the specimen successfully. This machine appears to be promising for evaluation of fatigue properties for micro-sized specimens for MEMS applications.

REPLICATION OF NANO/MICRO QUARTZ MOLD BY HOT EMBOSSING AND ITS APPLICATION TO BOROSILICATE GLASS EMBOSSING

2008 ◽  
Vol 22 (31n32) ◽  
pp. 6118-6123 ◽  
Author(s):  
SUNG-WON YOUN ◽  
CHIEKO OKUYAMA ◽  
MASHARU TAKAHASHI ◽  
RYUTARO MAEDA
Keyword(s):  
High Performance ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Hot Embossing ◽  
High Fidelity ◽  
Borosilicate Glasses ◽  
Mems Devices ◽  
Barrier Layers ◽  
Multiple Copies ◽  
Micro Electromechanical System

Glass hot-embossing is one of essential techniques for the development of high-performance optical, bio, and chemical micro electromechanical system (MEMS) devices. This method is convenient, does not require routine access to clean rooms and photolithographic equipment, and can be used to produce multiple copies of a quartz mold as well as a MEMS component. In this study, quartz molds were prepared by hot-embossing with the glassy carbon (GC) masters, and they were applied to the hot-emboss of borosilicate glasses. The GC masters were prepared by dicing and focused ion beam (FIB) milling techniques. Additionally, the surfaces of the embossed quartz molds were coated with molybdenum barrier layers before embossing borosilicate glasses. As a result, micro-hot-embossed structures could be developed in borosilicate glasses with high fidelity by hot embossing with quartz molds.

Research on Fatigue Test of LZ20Mn2 Axle Pipe Steel

2010 ◽  
Vol 44-47 ◽  
pp. 2152-2156
Author(s):  
Hong Lei Dong ◽  
Zhong Guo Huang ◽  
Qing Hua Yuan ◽  
Jia Fan
Keyword(s):  
Crack Initiation ◽  
Fatigue Test ◽  
Pipe Steel ◽  
Test Method ◽  
Fatigue Properties ◽  
Dog Bone ◽  
Slow Decline ◽  
Ultrasonic Fatigue ◽  
Dislocation Crack ◽  
Closure Effect

The core of ultrasonic accelerate fatigue test is resonance, and specimens need resonating with the system. The ultrasonic fatigue test method was used to investigate the high cycle fatigue properties of LZ20Mn2 axle pipe steel. Tests were conducted on cylindrical dog-bone specimens, and all fatigue loadings were controlled by inputting vibration amplitude. The results showed that the S-N curve of LZ20Mn2 axle pipe steel presented a slow-decline shape and subsurface crack initiation. The fatigue fracture was observed by SEM. Two different crack initiation mechanisms were observed which were the mixed inclusions and dislocation. Crack closure effect played an important role at fatigue crack propagation area and the fracture mechanism was a typical plastic fracture.

Three Ways of Sampling and Fatigue Test Results of Steel P92

2014 ◽  
Vol 891-892 ◽  
pp. 273-277
Author(s):  
Josef Volák ◽  
Zbynek Bunda
Keyword(s):  
Mechanical Properties ◽  
Power Plant ◽  
Fatigue Test ◽  
Fatigue Tests ◽  
Energy Industry ◽  
Fatigue Properties ◽  
Test Results ◽  
Steam Turbines ◽  
Standard Samples ◽  
Energy Component

This paper describes the fatigue properties of the steel P92. This material is widely used in the energy industry, especially for pipes and pipe bends of supercritical steam turbines. Steel P92 is alloyed with 2 % of tungsten compared to steel P91. This increases a creep strenght of the material. It is possible to reduce wall thickness of the P92 pipe up to about 20%. Fatigue tests were carried out on standard samples and compared with SFT samples (Small Fatigue Test). Using the device SSam 2 made by company Rolce Royce, it is possible to gently remove a samples from energy component without power plant shutdowns. Consider these correlations, i tis possible to determine mechanical properties of the material from small amount of removed experimental material.

scholarly journals Using Fatigue Characteristics to Analyse Test Results for 16Mo3 Steel under Tension-Compression and Oscillatory Bending Conditions

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1197 ◽  
Author(s):  
Andrzej Kurek
Keyword(s):  
Compression Test ◽  
Experimental Tests ◽  
Fatigue Tests ◽  
Test Method ◽  
Fatigue Properties ◽  
Test Results ◽  
Bending Tests ◽  
Fatigue Characteristics ◽  
Cost Efficient ◽  
Plastic Components

In this study, 16Mo3 steel was analysed for fatigue tests under tension-compression and oscillatory bending conditions. The analysis involved a comparison of fatigue test results obtained using the Manson-Coffin-Basquin, Langer and Kandil models and the models proposed by Kurek-Łagoda. It was observed that it is possible to substitute the basic tension-compression test performed in large testing machines with oscillatory bending tests carried out on a simple, modern test stand. The tests were performed under oscillatory bending on a prototype machine. The testing of 16Mo3 steel proved that the best-known Mason-Coffin-Basquin fatigue characteristic describes the results of all of the experimental tests very well, but the model can only be used when it is possible to divide strains into elastic and plastic components. It should be emphasised here that there is no such possibility in the case of tests performed under oscillatory bending conditions. It was proven that the proposed test method can substitute the tension-compression test very well and be a much more cost efficient way to obtain LCF material fatigue properties.

Effect of Pre-Strain on Fatigue Properties of NHH Rail

2004 ◽  
Vol 261-263 ◽  
pp. 1239-1244
Author(s):  
Wen Xian Sun ◽  
S. Nishida ◽  
Nobusuke Hattori ◽  
X.L. Yue
Keyword(s):  
Fatigue Crack ◽  
Fatigue Strength ◽  
Fatigue Test ◽  
Fatigue Cracks ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Slip Lines ◽  
Propagation Behavior ◽  
Strain Process ◽  
Initiation And Propagation

In the present study, fatigue tests have been performed to study the effect of pre-strain on fatigue properties of NHH (New Head-Hardened) rail. The objectives of this study were: (1) to observe the microscopic behavior of specimens during pre-strain process, (2) to research the influence of pre-strain on fatigue strength of NHH rail and (3) to investigate initiation and propagation behavior of the fatigue crack. The results showed that plastic pre-strain decreased the fatigue strength of NHH rail; fatigue limits had no obvious variation among the different pre-strain ratios. Fatigue cracks initiated in the microscopic cracking or slip lines that were originated in the pre-strain process and propagated from these sites in the later fatigue test.

Crude Oil Corrosion Fatigue of L485MB Pipeline Steel

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Ľ. Gajdoš ◽  
M. Šperl ◽  
J. Bystrianský
Keyword(s):  
Crude Oil ◽  
Strain Rate ◽  
Corrosion Fatigue ◽  
Pipeline Steel ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Oil Pipeline ◽  
Oil Processing ◽  
Tension Loading ◽  
Aggressive Effect

An investigation was made into the fatigue properties of L485MB (X70) pipeline steel after 13 yr of exploitation as a crude oil pipeline material. Fatigue tests in zero-to-tension loading were carried out (i) in air, (ii) in crude oil, (iii) in a mixture of crude oil with rainwater, and (iv) in water separated from the crude oil phase. The aim of the investigation was to assess the degree of degradation of the fatigue properties of this steel due to the action of environments typical for crude oil processing and transport. The results are not directly comparable to any corrosion fatigue experienced by the crude oil pipeline, since the strain rate for the tests was higher by an order of five than the strain rate observed in typical loading cycles. The results showed that crude oil and a mixture of crude oil with rainwater had no aggressive effect on the steel in the sense of reducing its fatigue characteristics, while the separated water had an aggressive effect.

Verification of the Fatigue Test Method Applied with the Use of Mini Specimen

2014 ◽  
Vol 598 ◽  
pp. 243-248 ◽  
Author(s):  
Tomasz Tomaszewski ◽  
Janusz Sempruch
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Test ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Construction Material ◽  
Test Method ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Testing Methodology ◽  
Standard Specimens

In special situations the fatigue properties of the construction material can be determined using non-standard specimens, for example smaller than the normative ones (the so-called mini specimens). The research presented was made for the aluminum alloy based on the high-cycle fatigue testing methodology. The verification was made by breaking down the results with own tests which involved the use of standard specimens and stands as well as with the literature reports.

Dynamic Recrystallization of Sn3.0Ag0.5Cu Pb-Free Solder Alloy

2008 ◽  
Author(s):  
Ken Holdermann ◽  
Gayatri Cuddalorepatta ◽  
Abhijit Dasgupta
Keyword(s):  
Grain Size ◽  
Focused Ion Beam ◽  
Solder Joints ◽  
Ion Beam ◽  
Fatigue Tests ◽  
Sac305 Solder ◽  
Creep Tests ◽  
Lap Shear ◽  
Mechanical Cycling ◽  
Sac Solder

This study examines microstructural recrystallization in Sn3.0Ag0.5Cu (SAC305) solder joints due to isothermal, mechanical cycling. It is well known that after reflow SAC solder joints at length scales of 200 μm consist of only a few grains [1–3]. This coarse microstructure makes the joint mechanically inhomogeneous and anisotropic, and non-repeatable. Creep tests conducted on modified lap-shear SAC305 solder joints therefore show significant scatter in their results, because of piece-to-piece variability in the microstructural morphology [1]. However, results of cyclic fatigue tests of the same SAC305 solder joints show less significant scatter [4]. One possible hypothesis is that dynamic recrystallization occurs during the cycling, resulting in a much finer (and hence more isotropic, homogeneous and repeatable) microstructure. Recrystallization of solder has been reported to occur under thermal cycling [5–6]. The objective of this study is to assess the extent of recrystallization of SAC305 solder during isothermal mechanical cycling fatigue. Focused ion beam technology is used to prepare a very clean and even surface to reveal the SAC305 grains in modified lap-shear test specimens, both before and after isothermal mechanical cycling. Polarized light microscopy, scanning electron microscopy and focused ion beam microscopy are used to reveal the microstructure of these SAC305 solder joints. The results show that mechanical cycling produces the same type of recrystallization behavior of SAC solder, as has been reported in the literature for thermally cycled specimens [5–6]. The number of grains in the SAC305 solder joint changes from a few to hundreds, during mechanical cycling. As expected, the recrystallization is observed to be localized around cracks in the solder joint, where the local stresses are the highest. The minimal grain size near the cracked region is approximately 4–6 μm and the average grain size increases significantly with increasing distance from the crack face. The transition of solder from very few (non-homogeneous and anisotropic) to a homogenous recrystallized state may be one possible explanation for differences in the extent of scatter in the data from creep tests and isothermal mechanical fatigue tests.

FIB-Based Fatigue Testing of Silicon Nitride Thin Films for Space Applications

2004 ◽  
Vol 851 ◽  
Author(s):  
Wen-Hsien Chuang ◽  
Rainer K. Fettig ◽  
Reza Ghodssi
Keyword(s):  
Thin Films ◽  
Silicon Nitride ◽  
Focused Ion Beam ◽  
Fatigue Testing ◽  
Ion Beam ◽  
Fatigue Properties ◽  
Test Duration ◽  
Electrostatic Actuator ◽  
Space Applications ◽  
James Webb Space Telescope

ABSTRACTA novel micro-scale electrostatic actuator has been designed and fabricated to study fatigue properties of low-stress LPCVD silicon nitride thin films, which are the structural materials of microshutter arrays to be used in NASA's James Webb Space Telescope (JWST). To obtain different stress levels without high applied voltages, the electrostatic actuator was designed based on a resonant technique to achieve mechanical amplification. All fabricated devices were tested inside a focused-ion-beam (FIB) system with pressure of 10-6 torr at room temperature (23 ± 1 °C) and with the test duration ranging from 5 seconds to 8.5 hours, 105 to 109 cycles, respectively. From the experiment, no fatigue failure of low-stress LPCVD silicon nitride thin films has been observed up to 109 testing cycles, four orders of magnitude higher than the expected lifetime of the microshutter arrays. The presented test device and experimental technique can be extended to characterize fatigue properties for other thin film materials.

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