scholarly journals Mechanical Properties Measurement of Polymer Films by Bulge Test and Fringe Projection

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
C. S. Lin ◽  
T. L. Horng ◽  
J. H. Chen ◽  
K. H. Chen ◽  
J. J. Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Poisson Ratio ◽  
Applied Pressure ◽  
Fringe Projection ◽  
Bulge Test ◽  
Element Analysis ◽  
Membrane Deformation ◽  
Test Film ◽  
Gas Chamber

This paper aims at determining the mechanical properties such as Poisson ratio, biaxial modulus, and residual stress of polymer membranes using the bulge test and fringe projection. Under this idea, a bulge test apparatus has been developed for robust usage, under the room temperature, in industrial environments that are usually noisy and full of all kinds of vibrations. A setup of the bulge test, consisting of single chips and digital on-off valves, was used to achieve automatic precision control of pressure application to gas chamber with a circular polyimide (PI) test film fixed on the opening of it. A deformed image was then obtained via fringe projections with a series of optical apparatuses, and a 3D membrane deformation distribution was further achieved from this deformed image by some image processes that are chiefly through wavelet transformation and phase expansion. With the measurements of maximum membrane deformation versus applied pressure and given the Young’s modulus of test membrane, we could further calculate the Poisson ration (and then biaxial modulus) and residual stress of the film. Also, the measurements were validated to be highly accurate by comparison with a finite element analysis.

Measurement of Young's Modulus and Poisson's Ratio of Thin Film by Combination of Bulge Test and Nano-Indentation

2008 ◽  
Vol 33-37 ◽  
pp. 969-974 ◽  
Author(s):  
Bong Bu Jung ◽  
Seong Hyun Ko ◽  
Hun Kee Lee ◽  
Hyun Chul Park
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Applied Pressure ◽  
Indentation Test ◽  
Poisson's Ratio ◽  
Bulge Test ◽  
Nano Indentation

This paper will discuss two different techniques to measure mechanical properties of thin film, bulge test and nano-indentation test. In the bulge test, uniform pressure applies to one side of thin film. Measurement of the membrane deflection as a function of the applied pressure allows one to determine the mechanical properties such as the elastic modulus and the residual stress. Nano-indentation measurements are accomplished by pushing the indenter tip into a sample and then withdrawing it, recording the force required as a function of position. . In this study, modified King’s model can be used to estimate the mechanical properties of the thin film in order to avoid the effect of substrates. Both techniques can be used to determine Young’s modulus or Poisson’s ratio, but in both cases knowledge of the other variables is needed. However, the mathematical relationship between the modulus and Poisson's ratio is different for the two experimental techniques. Hence, achieving agreement between the techniques means that the modulus and Poisson’s ratio and Young’s modulus of thin films can be determined with no a priori knowledge of either.

Three-Dimensional Numerical Simulation of Temperature Field and Force Field of T-Type Turbe during Welding

2013 ◽  
Vol 690-693 ◽  
pp. 2659-2663
Author(s):  
Jian Ping Zhou ◽  
Xiang Feng Zhang ◽  
Hong Sheng Liu ◽  
Jun Yi Gao ◽  
Yan Xu
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Temperature Field ◽  
Three Dimensional ◽  
Welding Process ◽  
Three Dimension ◽  
Analysis Software ◽  
Element Analysis ◽  
Cool Process ◽  
Type Tube

Residual stress affect the lifetime of weldments directly. Temperature Generated from the welding process is the major reason that influences the microstructure and mechanical properties of the metal weldments. Therefore it is necessary to simulate the temperature field for optimizing the structure of weldments. In this work the three-dimension finite element analysis software SYSWELS was used to simulate T-type tube, and carried on a detailed analysis of temperature field and residual stress in cool process of weld.

Structural Reliability of SU-8 Material for MEMS Application

2005 ◽  
Author(s):  
S. B. Park ◽  
Soonwan Chung ◽  
Sandeep Makhar ◽  
Harold Ackler ◽  
Pinyen Lin
Keyword(s):  
Elastic Modulus ◽  
Structural Reliability ◽  
Applied Pressure ◽  
Strain Energy Release ◽  
Bulge Test ◽  
Membrane Thickness ◽  
Element Analysis ◽  
Interfacial Toughness ◽  
Dog Bone ◽  
The Relationship

Mechanical properties of SU-8 over the range of temperature, −50 to 250 °C, were measured. Traditional tension test is performed with the dog-bone specimens using microfabrication techniques. The bulk properties such as elastic modulus, Poisson’s ratio and tensile strength are obtained in various temperatures. Bulge test is performed using SU-8 membrane constrained by silicon wafer. Pressure is applied to the membrane, and by analyzing the deflection of membrane, the elastic modulus and residual stress of SU-8 thin film are acquired. The relationship between applied pressure and deflection is obtained by changing some geometric parameters such as membrane thickness and diameter. The interfacial fracture toughness between SU-8 and silicon will measured using the membrane structure. The interfacial toughness obtained from the experiments will be compared with the strain energy release rate from finite element analysis, and the failure analysis at the interface under the actual thermal fatigue environment will be investigated using a numerical model.

scholarly journals Investigation of the Young’s Modulus and the Residual Stress of 4H-SiC Circular Membranes on 4H-SiC Substrates

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 801 ◽  
Author(s):  
Jaweb Ben Messaoud ◽  
Jean-François Michaud ◽  
Dominique Certon ◽  
Massimo Camarda ◽  
Nicolò Piluso ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Young’S Modulus ◽  
Microelectromechanical Systems ◽  
Film Growth ◽  
Electrochemical Etching ◽  
Young's Modulus ◽  
Fabrication Process ◽  
Bulge Test ◽  
Residual Strains

The stress state is a crucial parameter for the design of innovative microelectromechanical systems based on silicon carbide (SiC) material. Hence, mechanical properties of such structures highly depend on the fabrication process. Despite significant progresses in thin-film growth and fabrication process, monitoring the strain of the suspended SiC thin-films is still challenging. However, 3C-SiC membranes on silicon (Si) substrates have been demonstrated, but due to the low quality of the SiC/Si heteroepitaxy, high levels of residual strains were always observed. In order to achieve promising self-standing films with low residual stress, an alternative micromachining technique based on electrochemical etching of high quality homoepitaxy 4H-SiC layers was evaluated. This work is dedicated to the determination of their mechanical properties and more specifically, to the characterization of a 4H-SiC freestanding film with a circular shape. An inverse problem method was implemented, where experimental results obtained from bulge test are fitted with theoretical static load-deflection curves of the stressed membrane. To assess data validity, the dynamic behavior of the membrane was also investigated: Experimentally, by means of laser Doppler vibrometry (LDV) and theoretically, by means of finite element computations. The two methods provided very similar results since one obtained a Young’s modulus of 410 GPa and a residual stress value of 41 MPa from bulge test against 400 GPa and 30 MPa for the LDV analysis. The determined Young’s modulus is in good agreement with literature values. Moreover, residual stress values demonstrate that the fabrication of low-stressed SiC films is achievable thanks to the micromachining process developed.

scholarly journals Numerical Study on the Forming Behaviour of Multilayer Sheets

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 716
Author(s):  
Armando E. Marques ◽  
Pedro A. Prates ◽  
André F. G. Pereira ◽  
Nataliya A. Sakharova ◽  
Marta C. Oliveira ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Deep Drawing ◽  
Numerical Study ◽  
Physical And Mechanical Properties ◽  
Bulge Test ◽  
Geometrical Parameters ◽  
Equivalent Material ◽  
Element Analysis ◽  
Plastic Behaviour ◽  
Forming Behaviour

Nowadays, composite materials are playing an increasingly important role in material forming processes because they can combine remarkable physical and mechanical properties with relatively low weight. The main objective of this work is to study the forming behaviour of multi-layer sheets by finite element analysis. The possibility of replacing the composite by a single equivalent material, with a plastic behaviour similar to that of the composite, was also numerically analysed. This study focuses on two three-layer sheets, each composed of two metallic outer layers and a core of polymeric material; on one of the sheets, the outer layers are steel and, on the other, aluminium. Numerical simulations of the bulge test and of the deep drawing of a U-channel profile and a square cup were used to evaluate the behaviour of the multi-layer sheets and their equivalent materials. The influences of the difference of the mechanical properties of the constituent materials and some geometrical parameters of the deep-drawing process on the plastic behaviour, namely the curves of force vs. displacement of the punch and the strain and stress distributions, were evaluated. The possibility of using the bulge test to characterize the behaviour of the composite was also analysed.

Mechanical testing and microstructural characterisation of TiN thin films

1997 ◽  
Vol 505 ◽  
Author(s):  
A. Karimi ◽  
O. R. Shojaei ◽  
J. L. Martin
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Residual Stress ◽  
Silicon Nitride ◽  
Titanium Nitride ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Bulge Test ◽  
Tin Films ◽  
Deposition Parameters

ABSTRACTMechanical properties of titanium nitride (TiNx) thin films have been investigated using the bulge test and the depth sensing nanoindentation measurements. The bulge test was performed on the square free standing membranes made by means of standard micromachining of silicon wafers, while the nanoindentation was conducted on the films adhered to their supporting substrate. Thin layeres of titanium nitride (t = 300 – 1000 nm) were deposited in a r. f. magnetron sputtering system on the Si(100) wafers containing a layer of low stress LPCVD silicon nitride (SiNy). The bulge test was first conducted on the silicon nitride film to determine its proper residual stress and Young's modulus. Then, the composite membrane made of TiNx together with underlying silicon nitride was bulged and the related load-displacement variation was measured. Finally, using a simple rule of mixture formula the elastic mechanical properties of TiNx coatings were calculated. Both the Young's modulus and residual stress showed increasing values with negative bias voltage and nitrogen to titanium ratio, but the substrate temperature between 50–570°C was found less significant as compared to the other parameters. Nanoindentation data extracted from dynamically loading-unloading of TiN films converged to the bulge test measurements for compact coatings, but diverged from the bulge test data for porous coatings. Scanning electron microscopy observation of the cross sectioned specimens showed that TiN films first grow by formation of the nanocrystallites of size mostly between 10 – 15 nm. These nanocrystallites give rise to the columnar morphology beyond a thickness of 50–100 nm. The columns change their aspect with deposition parameters, but remain nearly perpendicular to the film surface. Relationship between microstructural evolution of columns and mechanical properties of coatings are discussed in terms of deposition parameters.

scholarly journals Temperature Field and Residual Stress of Butt Welding for IN182 Plate

2018 ◽  
Vol 7 (4.10) ◽  
pp. 95
Author(s):  
Harinadh Vemanaboina ◽  
G. Janardhana Raju ◽  
Bura Sreenivas
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Structural Changes ◽  
Welding Process ◽  
Industrial Applications ◽  
Butt Joint ◽  
Nonlinear Phenomenon ◽  
Element Analysis ◽  
Butt Welding ◽  
Effective Selection

The welding process is a nonlinear phenomenon in nature which leads to deformation and residual stresses in weldments. To overcome the structural changes in the weldments the computational packages can be effectively used for analyzing the changes in its life. Inconel superalloys have excellent mechanical properties and are used in the industrial applications. The present simulation is carried out for single pass butt-joint. Simulation studies are used for effective selection of process parameters for improving mechanical properties in the weld structures. In this work, coupled thermo-mechanical simulation process was carried out for predicting the temperatures, distortion and residual stress distribution in the weldments using Finite element analysis at the transverse direction on the welded surface.  

Measurement of Elastic Modulus and Residual Stress of Diamond Thin Films

2007 ◽  
Vol 329 ◽  
pp. 545-550 ◽  
Author(s):  
Dao Hui Xiang ◽  
Ming Chen ◽  
Y.P. Ma ◽  
Fang Hong Sun
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Residual Stress ◽  
Elastic Modulus ◽  
Young’S Modulus ◽  
Diamond Film ◽  
Young's Modulus ◽  
Effective Means ◽  
Bulge Test ◽  
Diamond Thin Films

Despite great advancements in diamond thin film growth and deposition techniques, determination of the residual stress and Young’s modulus for diamond films has continued to be a challenge. The bulge test is a potentially powerful tool for characterizing the mechanical properties of diamond film. In a bulge tester, pressure is applied on a thin membrane and the out-of-plane deflection of the membrane center is measured. The Young’s Modulus and the residual stress are simultaneously determined by using the load-deflection behavior of a membrane. By means of electron-enhanced hot filament chemical vapor deposition (HFCVD), a diamond film was deposited on silicon slice (100), and the free-standing window sample of diamond thin films was fabricated by means of photolithography and anisotropic wet etching. The deflection of the membranes is measured using a laser interferometry system. The elastic modulus and residual stress were measured using a self-designed bulge equipment. In addition, the distortion of diamond thin films under different pressure was simulated using finite element analysis and the contrast was made with experimental data. The research indicated that the Young’s Modulus of diamond thin films is 937.8GPa and the residual stress is -10.53MPa. The elastic modulus and the residual stress coincide with the report in the literature and the value tested by X-ray diffraction, respectively. This method uses a simple apparatus, and the fabrication of samples is very easy, and it has provided an effective means for precise measure the mechanical properties of other thin films.

Influence of aging on mechanical properties, wear and residual stress of a Heusler Al-Cu-Fe alloy

2019 ◽  
Vol 61 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Fazil Husem ◽  
Fatma Meydaneri Tezel ◽  
Muhammet Emre Turan
Keyword(s):  
Mechanical Properties ◽  
Residual Stress
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