Thermal Expansion of Polyether Ether Ketone Bearing Components

2019 ◽  
Vol 64 (4) ◽  
pp. 1-5 ◽  
Author(s):  
Bryan D. Allison ◽  
Connor M. Vanderwiel
Keyword(s):  
Thermal Expansion ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Aerospace Applications ◽  
Polyether Ether Ketone ◽  
Molded Parts ◽  
Injection Molded ◽  
Ether Ketone ◽  
Bearing Design ◽  
Strong Candidate

Carbon fiber–reinforced polyether ether ketone (PEEK) is a strong candidate for aerospace bearing cages due to its low density and good mechanical properties. However, there are still concerns regarding its performance at the elevated temperatures seen in aerospace applications. In particular, an accurate measurement of PEEK's coefficient of thermal expansion (CTE) is critical to proper bearing design. In this paper, the CTE of as-manufactured PEEK cages was measured to determine the range of CTE that can be expected for production parts. A range of cage sizes and designs were considered in this study. Components that were manufactured from stock shapes through subtractive methods were studied in addition to components made via injection molding. The CTE of machined PEEK was found to be significantly higher than that of injection-molded PEEK and also varied significantly from part to part. In contrast, the CTE of molded PEEK cages was found to be fairly consistent between parts. Finally, the CTE of PEEK was found to increase above the glass transition temperature of 143 °C, but it was demonstrated that this increase is relatively small for injection-molded parts.

scholarly journals In Situ Measurement of Carbon Fibre/Polyether Ether Ketone Thermal Expansion in Low Earth Orbit

Aerospace ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 35 ◽  
Author(s):  
Farhan Abdullah ◽  
Kei-ichi Okuyama ◽  
Isai Fajardo ◽  
Naoya Urakami
Keyword(s):  
Thermal Expansion ◽  
Carbon Fibre ◽  
Material Science ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Small Satellite ◽  
Polyether Ether Ketone ◽  
Ether Ketone ◽  
Orbit Data

The low Earth orbit (LEO) environment exposes spacecraft to factors that can degrade the dimensional stability of the structure. Carbon Fibre/Polyether Ether Ketone (CF/PEEK) can limit such degradations. However, there are limited in-orbit data on the performance of CF/PEEK. Usage of small satellite as material science research platform can address such limitations. This paper discusses the design of a material science experiment termed material mission (MM) onboard Ten-Koh satellite, which allows in situ measurements of coefficient of thermal expansion (CTE) for CF/PEEK samples in LEO. Results from ground tests before launch demonstrated the feasibility of the MM design. Analysis of in-orbit data indicated that the CTE values exhibit a non-linear temperature dependence, and there was no shift in CTE values after four months. The acquired in-orbit data was consistent with previous ground tests and in-orbit data. The MM experiment provides data to verify the ground test of CF/PEEK performance in LEO. MM also proved the potential of small satellite as a platform for conducting meaningful material science experiments.

Thermal Shrinkage Behavior of Battery Separator

2018 ◽  
Author(s):  
Shutian Yan ◽  
Jie Deng ◽  
Chulheung Bae ◽  
Xinran Xiao
Keyword(s):  
Thermal Expansion ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Porous Membrane ◽  
Thermal Shrinkage ◽  
Dynamic Mechanical Analyzer ◽  
Free Standing ◽  
Dynamic Mechanical ◽  
Battery Separator ◽  
Shrinkage Behavior

Battery separators are thin, porous membrane of 20∼30 microns thickness. Polymer separators display a significant amount of shrinkage at elevated temperatures. It is difficult to quantitatively characterize the large shrinkage behavior with a free standing separator sample. This paper examines the use of a dynamic mechanical analyzer under tensile mode in measuring the coefficient of thermal expansion (CTE) of three commonly used separators.

Studying Mechanical Properties Specially Fatigue Behavior of (Polyether Ether Ketone)/Glass Fiber Composites in Aerospace Applications

2014 ◽  
Vol 666 ◽  
pp. 8-16
Author(s):  
A. Saad Najim ◽  
Mohammed Adwaa
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
High Performance ◽  
Fatigue Behavior ◽  
Fatigue Properties ◽  
Glass Fiber Composites ◽  
Aerospace Applications ◽  
Polyether Ether Ketone ◽  
High Performance Composite ◽  
Ether Ketone

This work deals with studying the mechanical properties specially fatigue behavior for high performance composite materials of poly ether ether ketone (PEEK)/glass fiber, which are used in Aircraft Industry. Two materials have been used: (PEEK natural) and (PEEK+30% glass fiber).To identify the type of (PEEK), infrared (FTIR) test has been conducted. X-ray test has been used to measure the (PEEK) crystalline ,also the tensile properties, impact strength and the fatigue test are performed.The results show that FTIR test peaks are for standard PEEK polymer and that GFRP increases the crystalline of (PEEK) material , while the tensile , impact and fatigue properties of (PEEK) decreases by adding GF to PEEK .

Effect of aggregate type on linear thermal expansion of self-consolidating concrete at elevated temperatures

2012 ◽  
Vol 19 (3) ◽  
pp. 259-269 ◽  
Author(s):  
Tayfun Uygunoğlu ◽  
İlker Bekir Topçu
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Thermal Tests ◽  
Linear Change ◽  
Volcanic Tuff ◽  
Self Consolidating Concrete ◽  
Cement Ratio

AbstractIn this study, the effects of aggregate type on the coefficient of thermal expansion of self-consolidating concrete (SCC) produced with normal and lightweight (porous) aggregate (SCLC) were investigated. In experiments, three aggregate types, gravel, volcanic tuff, and diatomite, were used. Different combinations of water/cement ratio and superplasticizer dosage levels were prepared for the SCC and SCLC mixtures. Thermal tests were performed to accurately characterize the coefficient of thermal expansion (CTE) of SCC and SCLC aged 28 days using the dilatometer. The CTEs of SCC and SCLC were defined by measuring the linear change in length of concrete specimens subjected to a range of temperatures from 20°C to 1000°C. The results, in general, showed that SCLC has a lower CTE than that of SCC above 100°C. Moreover, CTE values of SCC and SCLC were decreased with increase in porous structure. The aggregate type has significant influence on the thermal properties of SCC.

scholarly journals Preparation and Properties of Inherently Black Polyimide Films with Extremely Low Coefficients of Thermal Expansion and Potential Applications for Black Flexible Copper Clad Laminates

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 576 ◽  
Author(s):  
Yao-yao Tan ◽  
Yan Zhang ◽  
Gang-lan Jiang ◽  
Xin-xin Zhi ◽  
Xiao Xiao ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Dimensional Stability ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Optical Transmittance ◽  
Molecular Structures ◽  
Molar Ratio ◽  
Optical Parameters ◽  
Aromatic Diamines ◽  
Potential Applications

In the current work, a series of black polyimide (PI) films with excellent thermal and dimensional stability at elevated temperatures were successfully developed. For this purpose, two aromatic diamines including 4,4′-iminodianline (NDA) and 2-(4-aminophenyl)-5- aminobenzimidazole (APBI) were copolymerized with pyromellitic dianhydride (PMDA) to afford PIs containing imino groups (–NH–) in the molecular structures. The referenced PI film, PI-ref, was simultaneously prepared from PMDA and 4,4′-oxydianiline (ODA). The introduction of imino groups endowed the PI films with excellent blackness and opaqueness with the optical transmittance lower than 2% at the wavelength of 600 nm at a thickness of 25 μm and lightness (L*) below 10 for the CIE (Commission International Eclairage) Lab optical parameters. Meanwhile, the introduction of rigid benzimidazole units apparently improved the thermal and dimensional stability of the PI films. The PI-d film based on PMDA and mixed diamines (NDA:APBI = 70:30, molar ratio) showed a glass transition temperature (Tg) of 445.5 °C and a coefficient of thermal expansion (CTE) of 8.9 × 10−6/K in the temperature range of 50 to 250 °C, respectively. It is obviously superior to those of the PI-a (PMDA-NDA, Tg = 431.6 °C; CTE = 18.8 × 10−6/K) and PI-ref (PMDA-ODA, Tg = 418.8 °C; CTE: 29.5 × 10−6/K) films.

Variation of lattice parameter and coefficient of thermal expansion of Mnln2S4 at elevated temperatures

1987 ◽  
Vol 6 (4) ◽  
pp. 489-490 ◽  
Author(s):  
V. Bhaskara Sastry ◽  
B. Appa Rao ◽  
P. V. Mohan Rao ◽  
K. Satyanarayana Murthy
Keyword(s):  
Thermal Expansion ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Lattice Parameter

Thermal expansion and pore pressure generation in oil sands

1986 ◽  
Vol 23 (3) ◽  
pp. 327-333 ◽  
Author(s):  
J. G. Agar ◽  
N. R. Morgenstern ◽  
J. D. Scott
Keyword(s):  
Thermal Expansion ◽  
Pore Pressure ◽  
Oil Sands ◽  
Thermal Stresses ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Oil Sand ◽  
Thermal Expansion Coefficients ◽  
Stress Changes ◽  
Expansion Coefficients

The prediction of stress changes and deformations arising from ground heating requires the coupled solution of the heat transfer and consolidation equations. Heat consolidation as a class of problems is distinct from other thermally induced consolidation problems involving processes such as frost heave and thaw consolidation in that it involves heating to elevated temperatures well above normal ground temperatures. Two of the important parameters required in analyses of heat consolidation problems are thermal expansion coefficients and a coefficient of thermal pore pressure generation.Relationships describing thermal expansion behaviour and thermal pore pressure generation in oil sands are presented. Both drained and undrained thermal expansion coefficients for Athabasca oil sand were determined by means of heating experiments in the temperature range 20–300 °C. The thermal pore pressure generation coefficient was evaluated in undrained heating experiments under constant total confining stresses and under constant effective confining stresses. The equipment and experimental methods developed during this study are appropriate for determination of thermal expansion and pore pressure generation properties of oil sands and other unconsolidated geologic materials. Key words: thermal expansion, oil sand, tar sand, thermal pore pressure generation, heat consolidation, thermal consolidation, coefficient of thermal expansion, thermal stresses, ground heating, thermally enhanced oil recovery, thermoelasticity, undrained heating.

scholarly journals Behaviour of flange joints in Steam Generator under thermal loads

2021 ◽  
Vol 309 ◽  
pp. 01082
Author(s):  
N. Rino Nelson
Keyword(s):  
Thermal Expansion ◽  
Contact Stress ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Pressure Vessels ◽  
Thermal Loads ◽  
Internal Fluid ◽  
Linear Behaviour ◽  
Loading And Unloading ◽  
Differential Thermal Expansion

Pressure vessels such as steam generators are subjected to high temperature, in addition to high pressure during the operating condition. Flanges and bolts are made up of different materials whose coefficient of thermal expansion varies. Usually, thermal expansion in bolts is greater than that of flanges. At elevated temperatures bolts expand more than that of flanges, resulting in decrease of compression in connected members achieved during assembly stage, which in turn decreases the contact stress in gasket. This can lead to leakage of internal fluid. The loss in gasket contact stress due to differential thermal expansion can be nullified by using sleeves of higher thermal expansion between the flange-nut and flange-bolt head interfaces. At higher temperatures sleeves expand more than bolts and flanges, pushing the flanges closer towards each other, thus decreasing gap created due to differential thermal expansion. The behaviour of gasketed blind flange joint with and without sleeves is analysed and the performances are compared under thermal loads. The non-linear behaviour of gaskets is included by specifying the loading and unloading characteristics with hysteresis.

scholarly journals Thermally conductive poly(ether ether ketone)/boron nitride composites with low coefficient of thermal expansion

2021 ◽  
Vol 56 (17) ◽  
pp. 10326-10337
Author(s):  
Barun Ghosh ◽  
Fang Xu ◽  
Xianghui Hou
Keyword(s):  
Thermal Expansion ◽  
Boron Nitride ◽  
Thermal Management ◽  
Coefficient Of Thermal Expansion ◽  
Weight Ratio ◽  
Thermal Dissipation ◽  
Ether Ether Ketone ◽  
Poly Ether Ether Ketone ◽  
Thermally Conductive ◽  
Ether Ketone

AbstractThe substantial heat generation due to miniaturization and high-degree integration of electronic devices is one of the major issues to facilitate efficient thermal management in power electronics. Though epoxy-based composites have shown great interest in different applications such as laminated circuit board, electronic component encapsulations, and potting, they have low application temperature (up to 150 °C) and higher mismatch of coefficient of thermal expansion (CTE) between the heat source and heat sink. Here, poly(ether ether ketone) (PEEK) composites reinforced with hexagonal boron nitride (hBN) nanoplatelets have been developed by liquid mixing and re-melting method for a step change in composite materials with lower CTE and significantly improved thermal dissipation capability. The lowest achieved CTE is 2.1 µm m−1 K−1, and the highest thermal conductivity is 1.04 W m−1 K−1 in PEEK/hBN composites at 30 wt% hybrid hBN content (hBN platelets with two different sizes, i.e. 70 nm and 500 nm, taken as 1:1 weight ratio), due to the formation of thermally conductive inter-filler networks. The composites show negligible variation in K with the working temperature up to 250 °C. The developed composites also exhibit excellent electrical insulation properties; thus, they will have good potential in thermal management for power electronic applications. Graphical abstract

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