History
of Carbon and Graphite Foams
Carbon foams were
first developed by researchers in the late 60’s as a reticulated vitreous
(glassy) carbon foam. Ford (1) reported on carbon foams produced by
carbonizing thermosetting organic polymer foams through a simple heat treatment.
Then, Googin et al. (2) at the Oak Ridge Atomic Energy Commission Laboratory
reported the first process dedicated to controlling the structure and material
properties of carbon and graphitic foams by varying the precursor material
(partially cured urethane polymer). In the several decades following
these initial discoveries, many researchers explored a variety of applications
for these materials (3-12) ranging from electrodes to insulating liners
for temperatures up to 2500°C. In fact, reticulated carbon foams
have been used as the template for many of the metal and ceramic foams currently
used in industry. In the 1970’s, research focused primarily
on producing carbon foams from alternative precursors. For example,
Klett, R. (6) at the Sandia National Laboratories produced the first carbon
foams from cork, a natural cellular precursor. Others worked on various
processing and precursor changes in an attempt to modify properties and
reduce cost. The majority of these carbon foams were used for thermal
insulation, although some structural applications were found.
In the early 1990’s,
researchers at the Wright Patterson Air Force Base Materials Lab pioneered
mesophase-derived graphitic foams, specifically for replacing expensive
3-D woven fiber performs in polymer composites and as replacements for honeycomb
materials (13-20). Their work was centered on developing a highly
structural material that was lightweight, and to date, exhibits the highest
specific strength of carbon foams. Concurrently, Ultramet Corp, performed
research on RVC foam and used chemical vapor deposition (CVD) as a technique
to place pyrolytic graphite on the glassy carbon ligaments of RVC, producing
3-D carbon structures with high-modulus ligaments.
With the goal of producing very inexpensive
carbon foams, researchers at West Virginia University developed a method
that used coal as a precursor for high strength foams with excellent thermal
insulation properties (21-24). In 1997, Klett, J. (25-35) at
the Oak Ridge National Laboratory (ORNL) reported the first graphitic foams
with bulk thermal conductivities greater than 40 W/m·K (recently,
conductivities up to 180 W/m·K have been measured (36)).
By combining an open cellular structure with a thermal conductivity to weight
ratio of greater than 200 (compared to 45 for copper), this material presents
a unique opportunity to radically change the approach to solving many heat
transfer problems. This graphite material has been examined for the
core of heat transfer devices such as radiators and heat sinks, evaporative
cooling and phase change devices. Furthermore, the ability of the graphite
foam to intercalate lithium and absorb acoustic energy makes them candidates
for several applications beyond thermal management.
References
- W. Ford, Method of Making Cellular Refractory
Thermal Insulating Material, US Patent 3,121,050, 1964.
- J. Googin, J. Napier, M. Scrivner, Method
for Manufacturing Foam Carbon Products, US Patent 3,345,440, 1967.
- F. C. Cowlard, J. C. Lewis, Journal of
Materials Science 2, 507-512 (1967).
- W. F. Knippenberg, B. Lersmacher, Phillips
Technical Review 36, 93-103 (1976).
- T. Noda, M. Inagaki, S. Yamada, Journal
of Non-Crystalline Solids 1, 285-302 (1969).
- R. D. Klett, High Temperature Insulating
Carbonaceous Material, US Patent 3,914,392, 1975.
- A. Bonzom, A. P. Crepaux, A.-M. E. J.
Montard, Process for Preparing Pitch Foams and Products so Produced, US
Patent 4,276,246, 1981.
- B. Ettinger, S. Wolosin, Refractory Porous
Bodies, US Patent 3,666,526, 1972.
- H. Luhleich, e. al., Method of Making
Carbonaceous Bodies, US Patent 3,927,187, 1975.
- R. Marek, W. Udichak, Foam Carbonization
and Resulting Structure, US Patent 3,922,334, 1975.
- H.-G. Franck et al., Process for Making
a Foam from a Composition Comprising Bituminous Masses, a Novolac, and Hexamethylenetetramine,
US Patent 3,784,487, 1974.
- C. Vinton, C. Franklin, Method for the
Preparation of Carbon Structures, US Patent 3,927,186, 1975.
- J. W. Hager, Materials Research Society
Symposium Proceedings 270, 41-46 (1992).
- J. W. Hager, D. P. Anderson, 21st Biennial
Conference on Carbon Extended Abstracts 1993.
- J. W. Hager, D. P. Anderson, 40th International
Sampe Symposium, Anaheim, California, May 8-11 1995.
- J. W. Hager, M. L. Lake, Materials Research
Society Symposium Proceedings 270, 29-34 (1992).
- J. W. Hager, J. W. Newman, N. Johannes,
F. H. Turrill, Carbon Artifacts and Compositions and Processes for Their
Manufacture, US Patent 6,013,371, 2000.
- S. S. Sandhu, J. W. Hager, Materials Research
Society Symposium Proceedings 270, 35-40 (1992).
- K. Kearns, 21st Annual Conference on Composites,
Materials, and Structures, Cocoa Beach, Florida, January 26-31 1997.
- K. M. Kearns, Process for Preparing Pitch
Foams, US Patent 5,868,974, 1999.
- A. H. Stiller, P. G. Stansberry, J. W.
Zondlo, Method of Making a Carbon Foam Material and Resultant Product, US
Patent 5,888,469, 1999.
- A. H. Stiller, A. Yocum, J. Plucinski,
Method of Making a Reinfoced Carbon Foam Material and Related Product, US
Patent 6,183,854, 1999.
- A. H. Stiller, P. Stansbery, J. Zondlo,
Method of Making a Carbon Foam Material and Resultant Product, US Patent
6,346,226, 2001.
- A. H. Stiller, P. Stansbery, J. Zondlo,
Method of Making a Carbon Foam Material and Resultant Product, US Patent
6,241,957, 1999.
- J. Klett, Proceedings of the 1998
43rd International SAMPE Symposium and Exhibition, Part 1 (of 2), Anaheim,
California, U.S.A., May 31-June 4 1998.
- J. Klett, Journal of Composites in Manufacturing
15, 1-7 (1999).
- J. Klett, Process for Making Carbon Foam,
US Patent 6,033,506, 2000.
- J. Klett, Pitch-Based Carbon Foam and
Composites, US Patent 6,261,485, 2001.
- J. Klett, Pitch Based Foam with Particulate,
US Patent 6,287,375, 2001.
- J. Klett, Method for Extruding Pitch Based
Foam, US Patent 6,344,159, 2002.
- J. Klett, Pitch Based Carbon Foam and
Composites, US Patent 6,387,343, 2002.
- J. Klett, Method of Casting Pitch Based
Foam, US Patent 6,398,994, 2002.
- J. Klett, T. Burchell, Pitch Based Carbon
Foam Heat Sink with Phase Change Material, US Patent 6,399,149, 2002.
- J. Klett, T. D. Burchell, Science and
Technology of Carbon, Strasbourg, France, July 8-9 1998.
- J. Klett, C. Walls, T. D. Burchell, Carbon
'99, Charleston, SC, July 11-16 1999.
- J. W. Klett, A. McMillan, N. Gallego,
“Carbon Foam for Electronics Cooling” (National Laboratory Fuel Cell Annual
Report, FY 2002).