Elevated-Temperature Thermal Expansion of PTFE/PEEK Matrix Composite With Random-Oriented Short Carbon Fibers and Graphite Flakes

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
A. Miyase ◽  
S. Qu ◽  
K. H. Lo ◽  
S. S. Wang
Keyword(s):  
Thermal Expansion ◽  
Elevated Temperature ◽  
Carbon Fibers ◽  
Matrix Composite ◽  
Polymer Matrix ◽  
Thermomechanical Properties ◽  
Scanning Calorimetry ◽  
Mechanical Coupling ◽  
Peek Composite ◽  
Short Carbon

Abstract A combined experimental and micromechanics investigation is conducted on elevated-temperature thermal expansion of PTFE/PEEK polymer-matrix composite reinforced with randomly oriented short carbon fibers (CF) and graphite flakes (Gr). In the experimental phase of the study, PTFE/PEEK polymer blends with different amounts of PTFE and four-phase CF/Gr/PTFE/PEEK composites with different volume fractions of graphite flakes were made from compression molding. Scanning electron microscopy was performed to evaluate the microstructure of the PTFE/PEEK matrix and the composite, especially the interface, and the size and dispersion of the particles. X-ray diffraction (XRD) was conducted to provide morphological information on the semi-crystalline PTFE/PEEK matrix of the composite. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were carried out to determine transition temperatures and thermomechanical properties of the composite and its constituent phases at the elevated temperature. Thermal expansions of neat PTFE and neat PEEK, the PTFE/PEEK polymer matrix, and the CF/Gr/PTFE/PEEK composite were obtained with a thermal–mechanical analyzer (TMA) in a dilatometric mode. Coefficients of thermal expansion (CTEs) of the PTFE/PEEK matrix and its CF/Gr/PTFE/PEEK composite were then determined from 25 °C up to an elevated temperature 240 °C. To augment the experimental study, micromechanics analyses are also conducted to determine thermal expansion coefficients of the PTFE/PEEK matrix and the CF/GR/PTFE/PEEK composite. The micromechanics solutions elucidate individual roles of different composite constituents, contributions of individual constituent materials’ temperature-dependent thermal and mechanical properties, the importance of composite microstructure and morphology, and the issue of thermal–mechanical coupling on the thermal expansion behavior of the complex CF/Gr/PTFE/PEEK composite at high temperature.

Application of fiber optic sensors for elevated temperature testing of polymer matrix composite materials

2011 ◽  
Vol 18 (1-2) ◽  
pp. 109-116
Author(s):  
John Montesano ◽  
Marina Selezneva ◽  
Cheung Poon ◽  
Zouheir Fawaz ◽  
Kamran Behdinan
Keyword(s):  
Elevated Temperature ◽  
Composite Materials ◽  
Matrix Composite ◽  
Polymer Matrix ◽  
Optical Sensors ◽  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Polymer Matrix Composite ◽  
Test Protocol ◽  
Temperature Applications

AbstractAdvanced polymer matrix composite (PMC) materials have been more frequently employed for aerospace applications due to their light weight and high strength. Fiber-reinforced PMC materials are also being considered as potential candidates for elevated temperature applications such as supersonic vehicle airframes and propulsion system components. A new generation of high glass-transition temperature polymers has enabled this development to materialize. Clearly, there is a requirement to better understand the mechanical behaviour of this class of composite materials. In this study, polyimide-coated fiber optic sensors are employed to continuously monitor strain in a woven carbon fiber bismaleimide (BMI) matrix laminate subjected to tensile static and fatigue loading at elevated temperatures. A unique experimental test protocol is utilized to investigate the capability of the optical sensors to monitor strain and track stiffness degradation of the composite material. An advanced interrogation system and an optical spectrum analyzer are utilized to track the variation in the optical fiber wavelength and the wavelength spectrum for correlation with strain gage measurements. Isothermal tensile static and fatigue tests at room temperature, 105°C, 160°C and 205°C suggest that these optical sensors are capable of continuously monitoring strain and tracking the stiffness loss of a highly compliant PMC specimen during cyclic loading. The results illustrate that employing optical sensors for elevated temperature applications has significant advantages when compared to conventional strain gages.

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.

Fracture Mechanisms in Fiber Reinforced Polymer Matrix Composites

2014 ◽  
Vol 1611 ◽  
pp. 153-158
Author(s):  
C. Rodríguez ◽  
M. Hinojosa ◽  
J. Aldaco ◽  
A. Cázares
Keyword(s):  
Carbon Fibers ◽  
Matrix Composite ◽  
Polymer Matrix ◽  
Epoxy Matrix ◽  
Polymer Matrix Composites ◽  
Glass Fibers ◽  
Fracture Mechanisms ◽  
Matrix Composites ◽  
Polyester Matrix ◽  
Epoxy Matrix Composite

ABSTRACTIn this work we report the fractographic study of polymer matrix composites specimens reinforced with glass and carbon fibers. Specimens of a polyester matrix composite with 30% of E-glass fibers are prepared and fractured in flexure mode. We also test an epoxy matrix composite with 30% carbon fibers, which is fractured in flexure mode. All specimens are manufactured based on the D790 ASTM standard for bending mode at room temperature. As an exception, the composites with epoxy matrix and reinforced with carbon fiber are cured in an autoclave. The most commonly observed fracture mechanisms are debonding in the interphase, delamination, Chevron lines, microbuckling, river patterns and radial fracture on the fibers.

Generation of Three-Dimensional Microstructure Model for Discontinuously Reinforced Composite by Modified Random Sequential Absorption Method

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Jiming Zhou ◽  
Lehua Qi ◽  
Arun M. Gokhale
Keyword(s):  
Carbon Fibers ◽  
Matrix Composite ◽  
Mechanical Response ◽  
Short Fibers ◽  
Alloy Matrix ◽  
Rsa Algorithm ◽  
Reinforced Composite ◽  
Microstructural Model ◽  
Microstructure Model ◽  
Short Carbon

Computer simulation of mechanical behavior of discontinuously reinforced composites containing randomly oriented short-fibers/whiskers presents an attractive opportunity for reduction of the number of experiments and resources required for microstructure design of such advanced materials. It is desirable to perform such simulations using microstructure model that accounts for randomness in angular orientations and locations of the short fibers/whiskers. In this contribution, a methodology is presented for efficient simulation of the required microstructural model through modification of well-known random sequential adsorption (RSA) algorithm for microstructure simulation through its application to the microstructure of Mg–alloy matrix composite containing randomly oriented short carbon fibers. The modified RSA algorithm enhances accuracy and efficiency of the complex geometric details of the randomly oriented short-fiber reinforced composite microstructure. Simulated microstructural model of composite is implemented in abaqus to simulate the mechanical response of the Mg–matrix composite containing randomly oriented short carbon fibers. The generated complex microstructure model in abaqus code is sliced into thin slices for reducing computing resources. The simulated results from multiple sliced models were averaged to approximate the result for the full volume element. The simulated mechanical response by use of multiple sliced models is validated via comparison with the experimental data.

Strain sensing using carbon fiber

1999 ◽  
Vol 14 (3) ◽  
pp. 790-802 ◽  
Author(s):  
Xiaojun Wang ◽  
Xuli Fu ◽  
D. D. L. Chung
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Matrix Composite ◽  
Epoxy Matrix ◽  
Strain Sensors ◽  
Cement Matrix ◽  
Strain Sensing ◽  
Fractional Change ◽  
Epoxy Matrix Composite ◽  
Short Carbon

Carbon fiber provides strain sensing through change in electrical resistance upon strain. Due to piezoresistivity of various origins, a single carbon fiber in epoxy, an epoxy-matrix composite with short carbon fibers (5.5 vol%), a cement-matrix composite with short carbon fibers (0.2–0.5 vol%), and an epoxy-matrix composite with continuous carbon fibers (58 vol%) are strain sensors with fractional change in resistance per unit strain up to 625. A single bare carbon fiber is not piezoresistive, but just resistive.

scholarly journals The Thermal Behavior of Lyocell Fibers Containing Bis(trimethylsilyl)acetylene

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 537
Author(s):  
Igor Makarov ◽  
Markel Vinogradov ◽  
Maria Mironova ◽  
Georgy Shandryuk ◽  
Yaroslav Golubev ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Thermal Behavior ◽  
Carbon Fibers ◽  
Coefficient Of Thermal Expansion ◽  
Structural Features ◽  
Amorphous Structure ◽  
Processing Temperature ◽  
Composite Fibers ◽  
Scanning Calorimetry ◽  
Lyocell Fibers

This study focuses on the preparation of carbon fiber precursors from solutions of cellulose in N-methylmorpholine-N-oxide with the addition of bis(trimethylsilyl)acetylene, studying their structural features and evaluating thermal behavior. The introduction of a silicon-containing additive into cellulose leads to an increase in the carbon yield during carbonization of composite precursors. The type of the observed peaks on the differential scanning calorimetry (DSC) curves cardinally changes from endo peaks intrinsic for cellulose fibers to the combination of endo and exo peaks for composite fibers. For the first time, coefficient of thermal expansion (CTE) values were obtained for Lyocell fibers and composite fibers with bis(trimethylsilyl)acetylene (BTMSA). The study of the dependence of linear dimensions of the heat treatment fibers on temperature made it possible to determine the relation between thermal expansion coefficients of carbonized fibers and thermogravimetric curves, as well as to reveal the relationship between fiber shrinkage and BTMSA bis(trimethylsilyl)acetylene content. Carbon fibers from composite precursors are obtained at a processing temperature of 1200 °C. A study of the structure of carbon fibers by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy made it possible to determine the amorphous structure of the fibers obtained.

Wear performance of the lead free tin bronze matrix composite reinforced by short carbon fibers

2009 ◽  
Vol 255 (13-14) ◽  
pp. 6647-6651 ◽  
Author(s):  
Zeng Jun ◽  
Xu Jincheng ◽  
Hua Wei ◽  
Xia Long ◽  
Deng Xiaoyan ◽  
...  
Keyword(s):  
Carbon Fibers ◽  
Matrix Composite ◽  
Lead Free ◽  
Wear Performance ◽  
Tin Bronze ◽  
Short Carbon ◽  
Bronze Matrix
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