Young’s modulus, thermal conductivity, electrical resistivity and coefficient of thermal expansion of mesophase pitch-based carbon fibers

Carbon ◽  
2014 ◽  
Vol 79 ◽  
pp. 274-293 ◽  
Author(s):  
Francisco G. Emmerich
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Thermal Expansion ◽  
Young’S Modulus ◽  
Carbon Fibers ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Mesophase Pitch

Determination of Mechanical Properties of Thin Film on Silicon Wafer

2003 ◽  
Author(s):  
Enboa Wu ◽  
Albert J. D. Yang ◽  
Ching-An Shao ◽  
C. S. Yen
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Thermal Expansion ◽  
Young’S Modulus ◽  
Silicon Wafer ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Poisson Ratio ◽  
Bulk State

Nondestructive determination of Young’s modulus, coefficient of thermal expansion, Poisson ratio, and thickness of a thin film has long been a difficult but important issue as the film of micrometer order thick might behave differently from that in the bulk state. In this paper, we have successfully demonstrated the capability of determining all these four parameters at one time. This novel method includes use of the digital phase-shifting reflection moire´ (DPRM) technique to record the slope of wafer warpage under temperature drop condition. In the experiment, 1-um thick aluminum was sputtered on a 6-in silicon wafer. The convolution relationship between the measured data and the mechanical properties was constructed numerically using the conventional 3D finite element code. The genetic algorithm (GA) was adopted as the searching tool for search of the optimal mechanical properties of the film. It was found that the determined data for Young’s modulus (E), Coefficient of Thermal Expansion (CTE), Poisson ratio (ν), and thickness (h) of the 1.00 um thick aluminum film were 104.2Gpa, 38.0 ppm/°C, 0.38, and 0.98 um, respectively, whereas that in the bulk state were measured to be E=71.4 Gpa, CTE=23.0 ppm/°C, and ν=0.34. The significantly larger values on the Young’s modulus and the coefficient of thermal expansion determined by this method might be attributed to the smaller dislocation density due to the thin dimension and formation of the 5-nm layer of Al2O3 formed on top of the 1-um thick sputtered film. The Young’s Modulus and the Poisson ratio of this nano-scale Al2O3 film were then determined. Their values are consistent with the physical intuition of the microstructure.

Tangguh LNG Project Statistical Young’s Modulus and Thermal Expansion Coefficient Testing of Clad Pipe Specimens

2011 ◽  
Author(s):  
Terry Griffiths ◽  
Isabel Hadley ◽  
Richard Johnson ◽  
Fabio Micari
Keyword(s):  
Thermal Expansion ◽  
Young’S Modulus ◽  
Room Temperature ◽  
Structural Reliability ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Linear Thermal Expansion ◽  
Upheaval Buckling ◽  
Analysis Of Results ◽  
Mean And Variance

Material testing was undertaken on samples taken from clad pipe manufactured by JSW for the Tangguh LNG project. The test programme involved testing Young’s Modulus (E) and Coefficient of Linear Thermal Expansion (α) from room temperature to above 110° on each layer. This paper summarises testing and analysis of results which enabled mean and variance on each material property to be found. Checks were also undertaken for any correlations in properties between clad and parent layers, and between Young’s Modulus and Coefficient of Thermal Expansion. Analysis results are compared to existing industry norms and their implications for the Tangguh project UHB (Upheaval Buckling) SRA (Structural Reliability Analysis) are summarised.

Friction and Wearing Behaviour of Sintered Composites Made from Copper Mixed with Carbon Fibers

2015 ◽  
Vol 660 ◽  
pp. 81-85 ◽  
Author(s):  
Radu Caliman
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Composite Materials ◽  
Friction Coefficient ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Coefficient Of Thermal Expansion ◽  
Density Ratio ◽  
Point Of View ◽  
Short Carbon

This paper presents a study regarding friction and wear comportment of sintered composite materials obtained by mixture of copper with short carbon fibers. Sintered composites are gaining importance because the reinforcement serves to reduce the coefficient of thermal expansion and increase the strength and modulus. In case of composites form by carbon fiber and copper, the thermal conductivity can also be enhanced. The combination of low thermal expansion and high thermal conductivity makes them very attractive for electronic packaging. Besides good thermal properties, their low density makes them particularly desirable for aerospace electronics and orbiting space structures. Compared to the metal itself, a carbon fiber-copper composite is characterized by a higher strength-to-density ratio, a higher modulus-to-density ratio, better fatigue resistance, better high-temperature mechanical properties and better wear resistance. Varying the percentage of short carbon fibers from 7,8% to 2,4%, and the percentage of copper from 92,2% to 97,6%, five dissimilar composite materials have been made and tested from the wear point of view. Friction tests are carried out, at room temperature, in dry conditions, on a pin-on-disc machine. The friction coefficient was measured using abrasive discs made from steel 4340 having the average hardness of 40 HRC, and sliding velocity of 0,6 m/sec. The primary goal of this study work it was to distinguish a mixture of materials with enhanced friction and wearing behaviour. The load applied on the specimen during the tests, is playing a very important role regarding friction coefficient and also the wearing speed.

Basic Research on Combinatorial Evaluation Method for Coefficient of Thermal Expansion

2007 ◽  
Vol 1024 ◽  
Author(s):  
Yuko Aono ◽  
Seiichi Hata ◽  
Junpei Sakurai ◽  
Ryusuke Yamauchi ◽  
Hiroyuki Tachikawa ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Thermal Behavior ◽  
Young’S Modulus ◽  
Evaluation Method ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Ccd Camera ◽  
Basic Research ◽  
Film Library ◽  
Combinatorial Methods

AbstractThe coefficient of thermal expansion (CTE) is one of the most important material properties for actuators driven by heat or structure over a wide temperature. The CTE of an alloy depends on its composition, and combinatorial methods are very effective for researching new alloys. A CTE evaluation method, which can be applied to combinatorial methods or a thin film library, is proposed in this paper. The thermal behavior of a bi-layer cantilever couple was used for the evaluation, and the Young's modulus, which is also an important property, was simultaneously obtained. Firstly, one bi-layer cantilever was fabricated and agreement of the thermal behavior with the theoretical behavior was confirmed. The estimated error of the measurement device (CCD camera) resolution was then analyzed. The results indicate that combinatorial evaluation does not enable an accurate evaluation of Young's modulus, but does allow the CTE be accurately determined.

Hierarchy in Extended Chain Polymers

1991 ◽  
Vol 255 ◽  
Author(s):  
P. E. Klunzinger ◽  
R. K. Eby ◽  
W. W. Adams
Keyword(s):  
Thermal Expansion ◽  
Young’S Modulus ◽  
Nonlinear Elasticity ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Fiber Axis ◽  
Computational Results ◽  
Negative Coefficient ◽  
Rigid Rod ◽  
Increasing Temperature

AbstractRigid rod polymers are of potential use in fibers for composites because of their high specific tensile strength and modulus as well as their high thermal stability. Some other common properties of systems meeting these criteria are a nonlinear elasticity (increasing Young's modulus with increasing tensile stress) and a negative coefficient of thermal expansion along the fiber axis. In composites, these two properties can combine to cause an increase of Young's modulus with increasing temperature and can lead to yielding or interfacial failure. The source of the nonlinear elasticity resides at two length scales: 1) the scale of the crystallites, (the reversible realignment of the crystallites along the fiber axis with increasing stress), and 2) at the scale of the molecules, (an inherent nonlinear elasticity of the molecules themselves). The former effect is reviewed and computational results for the latter are presented along with computational results for the molecular origin of the negative coefficient of thermal expansion.

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