High-Thermal-Conductivity Densified Graphitic Foams as Novel Bearing Materials

doi:10.1002/9780470291313.ch66

Title: High-Thermal-Conductivity Densified Graphitic Foams as Novel Bearing Materials

Full Record
Other Related Research

Abstract

The high-thermal-conductivity graphitic foams (foam-reinforced carbon-carbon composites) developed at ORNL have been mainly used for thermal management, as in heat sinks for electronic circuit boards and highly-efficient automotive radiators. However, recent studies in our laboratory have rather unexpectedly revealed their potential as novel bearing materials. In addition to their low density and potential for weight savings, there are three primary tribological advantages of the graphitic foam materials: (1) their graphitic structures provide self-lubricating qualities, (2) their extraordinarily high thermal conductivity aids in the efficient removal of frictionally-generated heat, and (3) the pores in the foam serve both as wear debris traps and lubricant reservoirs. Previous studies on the densified graphitic foam (DGF) sliding against steel and alumina at relatively low speed (1 m/s) and low load (10 N), revealed their encouraging self-lubricating behavior, comparable to solid graphite while much better than bronze and polytetrafluoroethylene (Teflon{trademark}). In this study, pin-on-disk tests with higher speeds (2, 6, and 10 m/s) and higher loads (322 N) were conducted on DGF and graphite disks sliding against a DGF pin. The surface temperature on the graphite disk increased rapidly due to frictional heating and the friction coefficient increased proportionally with surface temperature when it wasmore »« less

Authors:

Qu, Jun ^[1]; Blau, Peter Julian ^[1]; Klett, James William ^[1]; Jolly, Brian C ^[1]

ORNL

Publication Date:: Sun Jan 01 00:00:00 EST 2006

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE Laboratory Directed Research and Development (LDRD) Program

OSTI Identifier:: 1003288

DOE Contract Number:: AC05-00OR22725

Resource Type:: Conference

Resource Relation:: Journal Volume: 27; Conference: the 30th International Conference & Exposition on Advanced Ceramics & Composites, Cocoa Beach, FL, USA, 20060122, 20060127

Country of Publication:: United States

Language:: English

Citation Formats


                    Qu, Jun, Blau, Peter Julian, Klett, James William, and Jolly, Brian C. High-Thermal-Conductivity Densified Graphitic Foams as Novel Bearing Materials.  United States: N. p., 2006. 
        Web.  doi:10.1002/9780470291313.ch66.

Copy to clipboard


                    Qu, Jun, Blau, Peter Julian, Klett, James William, & Jolly, Brian C. High-Thermal-Conductivity Densified Graphitic Foams as Novel Bearing Materials.  United States.  doi:10.1002/9780470291313.ch66.

Copy to clipboard


                    Qu, Jun, Blau, Peter Julian, Klett, James William, and Jolly, Brian C. Sun .  
        "High-Thermal-Conductivity Densified Graphitic Foams as Novel Bearing Materials".  United States.  
        doi:10.1002/9780470291313.ch66.

Copy to clipboard


                    
@article{osti_1003288,

  title        = {High-Thermal-Conductivity Densified Graphitic Foams as Novel Bearing Materials},

  author       = {Qu, Jun and Blau, Peter Julian and Klett, James William and Jolly, Brian C},

  abstractNote = {The high-thermal-conductivity graphitic foams (foam-reinforced carbon-carbon composites) developed at ORNL have been mainly used for thermal management, as in heat sinks for electronic circuit boards and highly-efficient automotive radiators. However, recent studies in our laboratory have rather unexpectedly revealed their potential as novel bearing materials. In addition to their low density and potential for weight savings, there are three primary tribological advantages of the graphitic foam materials: (1) their graphitic structures provide self-lubricating qualities, (2) their extraordinarily high thermal conductivity aids in the efficient removal of frictionally-generated heat, and (3) the pores in the foam serve both as wear debris traps and lubricant reservoirs. Previous studies on the densified graphitic foam (DGF) sliding against steel and alumina at relatively low speed (1 m/s) and low load (10 N), revealed their encouraging self-lubricating behavior, comparable to solid graphite while much better than bronze and polytetrafluoroethylene (Teflon{trademark}). In this study, pin-on-disk tests with higher speeds (2, 6, and 10 m/s) and higher loads (322 N) were conducted on DGF and graphite disks sliding against a DGF pin. The surface temperature on the graphite disk increased rapidly due to frictional heating and the friction coefficient increased proportionally with surface temperature when it was higher than 40 C. The DGF disk, however, ran much cooler due to the higher thermal conductivity, and more impressively, the friction coefficient remained low and constant even at elevated disk temperatures. This suggests high potential for the graphitic foam material in weight-sensitive, high-speed, and elevated temperature bearing applications.},

  doi          = {10.1002/9780470291313.ch66},

  journal      = {},

  number       = ,

  volume       = 27,

  place        = {United States},

  year         = {Sun Jan 01 00:00:00 EST 2006},

  month        = {Sun Jan 01 00:00:00 EST 2006}

}

Copy to clipboard

Conference:

DOI: 10.1002/9780470291313.ch66

Other availability

Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

Heat Exchangers for Heavy Vehicles Utilizing High Thermal Conductivity Graphite Foams

Conference James Klett, Ron Ott ; April McMillan

Approximately two thirds of the world's energy consumption is wasted as heat. In an attempt to reduce heat losses, heat exchangers are utilized to recover some of the energy. A unique graphite foam developed at the Oak Ridge National Laboratory (ORNL) and licensed to Poco Graphite, Inc., promises to allow for novel, more efficient heat exchanger designs. This graphite foam, Figure 1, has a density between 0.2 and 0.6 g/cm 3 and a bulk thermal conductivity between 40 and 187 W/m{center_dot}K. Because the foam has a very accessible surface area (> 4 m 2 /g) and is open celled, themore »« less
Full Text Available
Electrical and thermal conductivity of loose and fibrous graphitic carbon materials at high temperatures

Journal Article Etinger, I.A. ; Mal'tseva, L.F. ; Lyakhin, Yu.P. ; ... - Heat Transfer - Sov. Res., v. 5, no. 2, pp. 7-10
METAL FOAMS: NOVEL MATERIALS FOR AIR COOLING AND HEATING APPLICATION- PERFORMANCE UNDER DRY, WET AND FROSTING CONDITIONS

Conference Nawaz, Kashif ; Jacobi, Anthony

Metal foams have emerged as a potential material for advanced heat exchangers in air-cooling systems. The novel materials have a large surface-area-to-volume ratio and a tortuous structure which promotes flow mixing in heat exchanger applications. The current study provides an overview of the thermal-hydraulic performance of metal foam heat exchangers under dry, wet and frosting operations. The experiments have been conducted in a wind tunnels at a range of operating conditions varying air flow rate, inlet air temperature and relative humidity and the associated pressure drop and heat transfer rate have been measured. The impact of metal foam geometry hasmore »« less
Full Text Available
Prediction and measurement of thermal transport across interfaces between isotropic solids and graphitic materials.

Conference Hopkins, Patrick E. ; Norris, Pamela M. ; Smoyer, Justin L. ; ...

Due to the high intrinsic thermal conductivity of carbon allotropes, there have been many attempts to incorporate such structures into existing thermal abatement technologies. In particular, carbon nanotubes (CNTs) and graphitic materials (i.e., graphite and graphene flakes or stacks) have garnered much interest due to the combination of both their thermal and mechanical properties. However, the introduction of these carbon-based nanostructures into thermal abatement technologies greatly increases the number of interfaces per unit length within the resulting composite systems. Consequently, thermal transport in these systems is governed as much by the interfaces between the constituent materials as it is bymore »« less
Prediction and measurement of thermal transport across interfaces between isotropic solids and graphitic materials.

Conference Norris, Pamela M. ; Smoyer, Justin L. ; Duda, John Charles. ; ...

Due to the high intrinsic thermal conductivity of carbon allotropes, there have been many attempts to incorporate such structures into existing thermal abatement technologies. In particular, carbon nanotubes (CNTs) and graphitic materials (i.e., graphite and graphene flakes or stacks) have garnered much interest due to the combination of both their thermal and mechanical properties. However, the introduction of these carbon-based nanostructures into thermal abatement technologies greatly increases the number of interfaces per unit length within the resulting composite systems. Consequently, thermal transport in these systems is governed as much by the interfaces between the constituent materials as it is bymore »« less
Full Text Available

Similar Records