scholarly journals Evaluation of the Coefficient of Thermal Expansion of Constituents in Composite Materials using an Inverse Analysis Scheme

2014 ◽  
Vol 27 (5) ◽  
pp. 393-401
Author(s):  
Jae Hyuk Lim ◽  
Dongwoo Sohn
Keyword(s):  
Thermal Expansion ◽  
Composite Materials ◽  
Inverse Analysis ◽  
Coefficient Of Thermal Expansion ◽  
Analysis Scheme

Thermal Property Evaluation of Chilled Aluminum-Alumina MMC

2015 ◽  
Vol 1101 ◽  
pp. 79-82
Author(s):  
B.C. Suresh ◽  
S.B. Arun
Keyword(s):  
Thermal Expansion ◽  
Composite Materials ◽  
Thermal Property ◽  
Coefficient Of Thermal Expansion ◽  
Matrix Material ◽  
High Strength ◽  
Stir Casting ◽  
Al Alloy ◽  
Industrial Growth ◽  
Property Evaluation

Now a day’s composite materials are taking very important role in industrial growth. Composite materials are widely used in Automobiles, aerospace, submarine and also in other major fields, due to their special characteristics like light weight, high strength, stiffness, corrosion resistance. The determination of Coefficient of Thermal Expansion (CTE) of MMCs is important to aid its usage in high temperature environment as in the case of automobile combustion chamber. In these applications the stability of the composites over a long period of operation is a critical design considerationPresent work deals with the thermal property evaluation of the Al alloy / alumina metal matrix composite developed using the Stir Casting with chilling route technique. LM 26 Al alloy is being selected as the matrix material as it is a potential alloy for automotive piston applications. Al alloy / alumina MMCs was cast under end chilling technique by dispersing the reinforcement from 6 to 12 wt% the steps of 3% to study the variation in its thermal properties. At the same time chill material is also changed (Copper and MS) for different composition of MMCs cast to study the thermal behavior variations. After casting the required MMC, test specimens were prepared as per the standards to conduct thermal conductivity (K) tests and coefficient of thermal expansion (CTE) tests. Above tests were repeated for different composites containing different weight % of dispersed cast using different chills.

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.

Composite materials with a low coefficient of thermal expansion

1974 ◽  
Vol 16 (6) ◽  
pp. 495-497 ◽  
Author(s):  
I. N. Fridlyander ◽  
N. S. Klyagina ◽  
I. D. Tykachinskii ◽  
�. P. Dain ◽  
G. D. Gordeeva
Keyword(s):  
Thermal Expansion ◽  
Composite Materials ◽  
Coefficient Of Thermal Expansion

scholarly journals Determination of the coefficient of expansion of a carbon tube and its assembly for thermal compensation of metrological structures

2019 ◽  
Author(s):  
Salma EL ASMAI ◽  
François HENNEBELLE ◽  
Thierry COOREVITS ◽  
Jean-François FONTAINE
Keyword(s):  
Thermal Expansion ◽  
Composite Materials ◽  
Production Efficiency ◽  
Coefficient Of Thermal Expansion ◽  
Thermal Expansion Coefficients ◽  
Carbon Tube ◽  
Interesting Approach ◽  
Measurement Uncertainties ◽  
3D Metrology

Composite materials are increasingly used in 3D metrology devices. Their use is justified by their interesting mechanical properties including their low density and good rigidity but especially their low coefficient of thermal expansion. In fact, in order to improve production efficiency, companies nowadays integrate more and more control equipment directly in situ. These are then subject to thermal variations. The use of composite materials is an interesting approach. However, in some cases, the lack of knowledge of their coefficient of thermal expansion and their behavior might increase measurement uncertainties. The objective is to study the thermal behavior of a carbon tube alone and the same tube with aluminium fixing elements at its extremities, in order to determine the coefficients of expansion of the carbon alone and to quantify the influence of the fixation with aluminium elements. This experiment makes it possible to directly compensate the dimensional variations of the metrological structure depending on the temperature variations and thus to limit measurement uncertainties. The thermal expansion coefficients of the carbon tube and its assembly are determined by measuring relative variations in height with a ZERODUR® reference bar. The whole is positioned in a climatic chamber. *

scholarly journals A method of manufactoring pipes from polymer composite materials for aircraft structures

2020 ◽  
Vol 26 (5) ◽  
pp. 228-27
Author(s):  
S.O. Odaisky ◽  
◽  
O.M. Potapov ◽  
S.V. Fedorenko ◽  
A.P. Shchudro ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Polymer Composite ◽  
Modulus Of Elasticity ◽  
Coefficient Of Thermal Expansion ◽  
Longitudinal Direction ◽  
Polymer Composite Materials ◽  
Thermophysical Characteristics ◽  
Reinforcement Scheme

The frame power structures are widely applied when designing aircraft, in which composite rod elements are used to reduce the mass and size characteristics. To solve the problem of manufacturing rod elements from polymer composite materials, we developed a technology for the manufacture of carbon fiber pipes using an existing machine for winding carbon fiber, which provides the necessary strength and rigidity mainly in the longitudinal direction.When calculating the rod elements, all the loads that will affect the structure as well as the coefficient of thermal expansion should be taken into account. To achieve the required physical, mechanical, and thermophysical characteristics, the optimal scheme of reinforcement is the scheme with a quasi-longitudinal direction of the fibers. We developed the method of manufacturing based on the technology allowing us to obtain a reinforcement scheme with fiber orientation in the quasi-longitudinal direction with a reinforcement angle of about 1° by a combined method of layer-by-layer winding of carbon fiber. As a result of technological testing, we obtained samples of carbon fiber rod elements, which were used to confirm the calculated characteristics. To confirm the physico-mechanical and thermophysical characteristics, we determined the assessment of limit of strength and modulus of elasticity in bending, the limit of strength and modulus of elasticity in torsion, the limit of strength and modulus of elasticity in compression, and the coefficient of thermal expansion. The obtained characteristics of the dependences of the elasticity modulus of the pipe prototype material at the fibers’ orientation angle correlate with theoretical calculations. The presented method has the patent UA 128613 U.

Composite Materials with Adjustable Thermal Expansion for Electronic Applications

1996 ◽  
Vol 445 ◽  
Author(s):  
J. D. Shi ◽  
Z. J. Pu ◽  
K. ‐H. Wu ◽  
G. Larkins
Keyword(s):  
Thermal Expansion ◽  
Composite Materials ◽  
Polymer Matrix ◽  
Polymer Matrix Composites ◽  
Coefficient Of Thermal Expansion ◽  
Large Temperature ◽  
Matrix Composites ◽  
Negative Coefficient ◽  
Volume Fractions ◽  
Low Thermal Expansion

AbstractIn this paper, we discuss a newly characterized compound, ZrW2Og, that has been introduced into the composite materials with an adjustable and low thermal expansion for electronic applications. Offering a negative coefficient of thermal expansion (CTE) of approximate ‐9xlO–6/°C in a large temperature range, ZrW2Og was used as a particle filler in polymer‐matrix composites. The paper presents two kinds of composites, that is, polyester and epoxy with various volume fractions of ZrW20g. The CTEs of the polyester/ZrW2Og and epoxy/ZrW2Og composites have been proven adjustable in the ranges of 94 to 56x10–6 /°C and 54 to 18х 10–6 /°C, respectively, with ZrW2Og filler from 0 to 30 vol%. In addition, the analysis about the interfaces between the matrices and filler indicated that the interfaces may be beneficial to reduce the overall thermal expansion of the composites. The methods to further decrease composite CTEs are also discussed.

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