Study of the thermal properties of polyester composites loaded with oriented carbon nanofibers using the front-face flash method

2016 ◽  
Vol 50 ◽  
pp. 255-261 ◽  
Author(s):  
Nelson W. Pech-May ◽  
Caridad Vales-Pinzón ◽  
Alejandro Vega-Flick ◽  
Ángel Cifuentes ◽  
Alberto Oleaga ◽  
...  
Author(s):  
Messiha Saad ◽  
Darryl Baker ◽  
Rhys Reaves

Thermal properties of materials such as specific heat, thermal diffusivity, and thermal conductivity are very important in the engineering design process and analysis of aerospace vehicles as well as space systems. These properties are also important in power generation, transportation, and energy storage devices including fuel cells and solar cells. Thermal conductivity plays a critical role in the performance of materials in high temperature applications. Thermal conductivity is the property that determines the working temperature levels of the material, and it is an important parameter in problems involving heat transfer and thermal structures. The objective of this research is to develop thermal properties data base for carbon-carbon and graphitized carbon-carbon composite materials. The carbon-carbon composites tested were produced by the Resin Transfer Molding (RTM) process using T300 2-D carbon fabric and Primaset PT-30 cyanate ester. The graphitized carbon-carbon composite was heat treated to 2500°C. The flash method was used to measure the thermal diffusivity of the materials; this method is based on America Society for Testing and Materials, ASTM E1461 standard. In addition, the differential scanning calorimeter was used in accordance with the ASTM E1269 standard to determine the specific heat. The thermal conductivity was determined using the measured values of their thermal diffusivity, specific heat, and the density of the materials.


2007 ◽  
Vol 124-126 ◽  
pp. 1079-1082 ◽  
Author(s):  
Sung Ryong Kim ◽  
Dae Hoon Kim ◽  
Dong Ju Kim ◽  
Min Hyung Kim ◽  
Joung Man Park

Thermal properties of PEEK/silicon carbide(SiC) and PEEK/carbon fiber(CF) were investigated from ambient temperature up to 200°C measured by laser flash method. Thermal conductivity was increased from 0.29W/m-K without filler up to 2.4 W/m-K with at 50 volume % SiC and 3.1W/m-K with 40 volume % carbon fiber. Values from Nielsen theory that predicts thermal conductivity of two-phase system were compared to those obtained from experiment.


Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 497
Author(s):  
Zuzanka Trojanová ◽  
Kristýna Halmešová ◽  
Ján Džugan ◽  
Zdeněk Drozd ◽  
Peter Minárik ◽  
...  

An AX52 magnesium alloy (nominal composition Mg-5Al-2Ca in w.%) was submitted to equal channel angular pressing (ECAP) using processing route A; 1–8 passes through the ECAP tool were applied. The thermal conductivity of the ECAP samples was measured using a flash method in the temperature interval from room temperature up to 350 °C. The microstructure and texture of the samples were studied by light and electron microscopy. The severe plastic deformation, realized by the ECAP, influences the thermal properties of the alloy. The possible microstructural parameters determining the thermal conductivity were analyzed. New dislocations, the grain, phase boundaries, and texture of the samples may perceptibly change the thermal properties.


e-Polymers ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 323-329 ◽  
Author(s):  
J. Sahari ◽  
M.A. Maleque

AbstractThis research was carried out to evaluate the effect of oil palm ash (OPA) on the mechanical and thermal properties of biocomposites. Different compositions of OPA (i.e. 0, 10, 20 and 30 vol%) were introduced to unsaturated polyester (UPE) by using simple casting method with methyl ethyl ketone peroxide (MEKP) as a hardener. The specimens were prepared based on ASTM D5083 standards for tensile testing. From the results, it was found that the mechanical properties of UPE/OPA composites were improved in modulus with increasing the OPA content. The physical properties of UPE/OPA were also investigated where the density of biocomposites decrease with increasing OPA while the water absorption of UPE/OPA increase with increasing OPA. The thermal and morphological characterization of the UPE/OPA composites have been done using TGA, DSC and SEM.


2011 ◽  
Vol 312-315 ◽  
pp. 577-582 ◽  
Author(s):  
Grzegorz Moskal ◽  
Lucjan Swadźba ◽  
Bartosz Witala

This article presents a study and results concerning the characteristics of selected thermal properties of the powders intended for deposition of gradient structure layers of the TBC type. The study included evaluation of the thermal diffusivity and specific heat of the powders in the initial state, and also calorimetric analysis of powder mixtures. Thermal diffusivity tests were performed with the laser-flash method. The temperature range of the tests was 25°C-1400°C. Specific heat and calorimetric analyses were performed with the heat flux method within a similar temperature range. The Gd2Zr2O7 powders obtained by spray drying method and standard ZrO2 x 8Y2O3 powder were analysed. The thermal diffusivity analysis and calorimetric analysis were performed for the samples obtained by pressing the Gd2Zr2O7 - ZrO2 x 8Y2O3 powder mixture of equal weight fractions. Specific heat measurements were taken for pure powders. The calorimetric analysis performed showed that no significant thermal effects were observed in both pure powders and their mixture within the temperature range of 800°C-1400°C. A small endothermic effect (approx.-7J/g) was observed for gadolinium powder within the temperature range of 350°C-615°C. Specific heat measurements revealed that gadolinium powder was characterized by stable values of that parameter within the whole temperature range like zirconium powder. The analyses performed showed that the powders were characterized by small mutual reactivity, and gadolinium powder showed a definitely lower thermal diffusivity, which is advantageous as regards obtaining TBC layers with a gradient structure on the basis of those two powders.


10.30544/392 ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 1-10
Author(s):  
Dragan Miroslav Manasijevic ◽  
Žarko Radović ◽  
Nada Štrbac ◽  
Ljubiša Balanović ◽  
Uroš Stamenković ◽  
...  

This work aims to investigate the microstructural and thermal properties of as-cast high carbon and high chromium cold work tool steel. The microstructure was investigated by using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD) method. It was determined that at room temperature the microstructure of the investigated tool steel includes a lamellar network of M7C3 carbide precipitates along grain boundaries of ferrite grains in the base. Thermal diffusivity, specific heat capacity and thermal conductivity of the investigated steel alloy were determined in the temperature interval from 25 to 400 °C by using the laser-flash method. Thermal conductivity increases from 24.9 at 25 °C to 26.9 W/m·K at 400 °C. Phase transition temperatures in the temperature region from room temperature to 1250 °C were experimentally determined using differential scanning calorimetry (DSC). One endothermic effect in the temperature interval from 803 to 820 °C, corresponding to the ferrite/austenite phase transformation, was detected during sample heating. Experimental results were compared with the results of phase equilibria calculations obtained from the ThermoCalc software and TCFE6 database.


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