Evaluating the Mechanical Properties of MEMS by Combining the Resonance Frequency and Microtensile Methods

2003 ◽  
Vol 782 ◽  
Author(s):  
Dongil Son ◽  
Jong-jin Kim ◽  
Dong Won Kim ◽  
Tae Won Lim ◽  
Dongil Kwon

ABSTRACTTensile, fracture and fatigue properties of single- and polycrystalline silicon and LIGA-Ni were evaluated by the resonance frequency and microtensile methods. A new method for evaluating the fracture toughness that combines these two methods was proposed. A pre-crack was generated in an electrostatically driven test specimen and a load was applied by piezoelectrically driven microtensile equipment. Before the microtensile test, a new surface micromachining technique including a two-step sacrificial layer removal was used. The pre-cracked specimen was attached to microtensile equipment by a UV-adhesive glass grip. The fatigue pre-crack was successfully introduced and the fracture toughness could be derived on the basis of fracture mechanics. The fracture toughness of the pre-cracked specimen was relatively low compared with that of the notched specimen, so that we were able to determine the effect of the notch tip radius. The fatigue properties of LIGA-Ni film were also evaluated. A tensile-tensile fatigue load was applied by a piezoelectric actuator, and real-time load-displacement curves were displayed via computer. The dependence of S-N curves, crack propagation rates and fatigue-notch factor on the applied load for 10 μm Ni film was analyzed.

Alloy Digest ◽  
1987 ◽  
Vol 36 (7) ◽  

Abstract AL TECH POTOMAC A has well-balanced strength and toughness which make it especially suitable for a wide variety of hot-die steel applications, including those involving severe coolants. Its outstanding mechanical properties make it useful for many non-tooling requirements such as aerospace components. For more specialized needs, the manufacturer offers special melting processes that enhance this steel's fatigue properties and transverse tensile ductility. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-478. Producer or source: AL Tech Specialty Steel Corporation.


Alloy Digest ◽  
1998 ◽  
Vol 47 (5) ◽  

Abstract Inland DuraSpring is a high-strength microalloyed spring steel for use in high stress coil springs for automobile and light truck suspension systems. This bar product offers significant improvements in tensile strength, fatigue properties, and fracture toughness compared to conventional spring steels. This datasheet provides information on composition, hardness, and tensile properties as well asfracture toughness and fatigue. Filing Code: SA-496. Producer or source: Ispat Inland Inc.


Alloy Digest ◽  
1979 ◽  
Vol 28 (4) ◽  

Abstract Cabot ESR HY 140 is a 5Ni-Cr-Mo-V alloy steel produced by electric-furnace melting, vacuum degassing and electroslag remelting (ESR) by use of small-heat-size technology. Electroslag refining improves cleanliness and lowers the sulfur content to provide improved isotropy, ductility and toughness. This steel is capable of developing a minimum yield strength of 140,000 psi with an optimum combination of hardenability, temperability, weldability, formability, toughness and fatigue properties. It meets many special requirements for petrochemical applications. This datasheet provides information on composition, physical properties, and elasticity as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-358. Producer or source: Cabot Corporation, Machinery Division.


2018 ◽  
Vol 122 (1255) ◽  
pp. 1352-1370 ◽  
Author(s):  
H. Liu ◽  
B.G. Falzon ◽  
G. Catalanotti ◽  
W. Tan

ABSTRACTCarbon fibres with high tensile strength are being increasingly utilised in the manufacture of advanced composite aerostructures. A Modified Compact Tension (MCT) specimen is often deployed to measure the longitudinal intralaminar fracture toughness but a high tensile strength often leads to premature damage away from the crack tip. We present an approach whereby the MCT specimen is supported by external fixtures to prevent premature damage. In addition, we have developed a novel measurement technique, based on the fibre failure strain and C-scanning, to determine the crack length in the presence of surface sublaminate delamination which masks the crack tip location. A set of cross-ply specimens, with a ((90/0)s)4 layup, were manufactured from an IMS60/epoxy composite system Two different data reduction schemes, compliance calibration and the area method, are used to determine the fibre-dominated initiation and propagation intralaminar fracture toughness values. Propagation values of fracture toughness were measured at 774.9 ± 5.2% kJ/m2 and 768.5 ± 4.1% kJ/m2, when using the compliance calibration method and the area method, respectively. Scanning Electron Microscopy (SEM) is carried out on the fracture surface to obtain insight into the damage mechanism of high-tensile-strength fibre-reinforced unidirectional composites. The measured tensile fracture toughness value is used in a fully validated computational model to simulate the physical test.


2011 ◽  
Vol 138-139 ◽  
pp. 832-835
Author(s):  
Yong Jie Liu ◽  
Qing Yuan Wang ◽  
Ren Hui Tian ◽  
Xiao Zhao

In this paper, tensile fatigue properties of 316L stainless steel thin sheets with a thickness of 0.1 mm are studied. The tests are implemented by using micro mechanical fatigue testing sysytem (MMT-250N) at room temperature under tension-tension cyclic loading. The S-N curve of the thin sheets descends continuously at low cycle region. Cyclic σ-N curve and ε-N curve are obtained according to the classical macroscopical fatigue theory. The results agree well with the experimental fatigue data, showing that the traditional fatigue research methods are also suitable for description of MEMS fatigue in a certain extent. The effect factor of frequency was considered in this study and the results show that the fatiuge life and the fatigue strength are increased as loading frequency increasing.


Author(s):  
Jae Hoon Kim ◽  
Duck Hoi Kim ◽  
Nam Su Rho ◽  
Young Shin Lee ◽  
Song Heo Koo ◽  
...  

2010 ◽  
Vol 25 (7) ◽  
pp. 1375-1387 ◽  
Author(s):  
Wen-Cai Liu ◽  
Jie Dong ◽  
Ping Zhang ◽  
Xing-Wei Zheng ◽  
Wen-Jiang Ding ◽  
...  

The influence of shot peening (SP) on high cycle fatigue (HCF) performance of smooth and notched specimens of hot-extruded ZK60 magnesium alloy was investigated and compared to that of hot-extruded and T5 aging-treated ZK60 magnesium alloy referred to as ZK60-T5. The increases in fatigue properties at the optimum Almen intensities were found to depend on the material states. In contrast to ZK60 alloy, higher smooth and notched fatigue properties for both unpeened and peened specimens were observed for ZK60-T5 alloy. Meanwhile, the improvement of fatigue life for notched specimen by SP was much more than that for the smooth specimen. The mechanism by which the compressive residual stress induced by SP resulted in the improvement of fatigue performance of smooth and notched specimens for ZK60 and ZK60-T5 alloys was discussed.


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