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Mati Berman Falk
What is the basic difference between graphite epoxy composite and...
Well graphite is an allotrope of carbon and so one could say that composites made of carbon and graphite are same yet there is a difference. The degree of manufacture is quite different thus exhibit different properties. As such, they two shouldn't be used interchangeably
Well graphite is an allotrope of carbon and so one could say that composites made of carbon and graphite are same yet there is a difference. The degree of manufacture is quite different thus exhibit different properties. As such, they two shouldn't be used interchangeably
Graphite epoxy polymeric composite: Graphite particulate or Graphite flake is reinforced in epoxy resin matrix. Carbon epoxy polymeric composite: Carbon fibre having a particular aspect ratio is reinforced in epoxy resin matrix.
Graphite epoxy polymeric composite: Graphite particulate or Graphite flake is reinforced in epoxy resin matrix. Carbon epoxy polymeric composite: Carbon fibre having a particular aspect ratio is reinforced in epoxy resin matrix.
there is no difference. In both cases you have a carbon fibre reinforced epoxy resin (CFRP). Sometimes people use the term graphite fibres instead of carbon fibre which is not correct. There doesn't exist a graphite fibre. A graphite modification in common sense has a lattice distance of 0,335 nm.
HT (High tensile strength) carbon fibres based on PAN (polyacrylonitrile) normally have a lattice distance between 0,355 and 360 nm when treated at temperatures around 1400 - 1500 °C.
If such an HT fibre is post heat treated at temperatures around 2500 °C you get an lattice distance which is around 0,345 nm which is still far away from a graphite structure.
HM (High modulus fibres) carbon fibres based on mesophase pitch can reach around 2500 °C a lattice distance of around 0,342 which is also no graphitic lattice distance.
a literature reference you might find at Wilhelm Frohs, University of Karlsruhe (approx. 1988-1990)
there is no difference. In both cases you have a carbon fibre reinforced epoxy resin (CFRP). Sometimes people use the term graphite fibres instead of carbon fibre which is not correct. There doesn't exist a graphite fibre. A graphite modification in common sense has a lattice distance of 0,335 nm.
HT (High tensile strength) carbon fibres based on PAN (polyacrylonitrile) normally have a lattice distance between 0,355 and 360 nm when treated at temperatures around 1400 - 1500 °C.
If such an HT fibre is post heat treated at temperatures around 2500 °C you get an lattice distance which is around 0,345 nm which is still far away from a graphite structure.
HM (High modulus fibres) carbon fibres based on mesophase pitch can reach around 2500 °C a lattice distance of around 0,342 which is also no graphitic lattice distance.
a literature reference you might find at Wilhelm Frohs, University of Karlsruhe (approx. 1988-1990)
there is no difference. In both cases you have a carbon fibre reinforced epoxy resin (CFRP). Sometimes people use the term graphite fibres instead of carbon fibre which is not correct. There doesn't exist a graphite fibre. A graphite modification in common sense has a lattice distance of 0,335 nm.
HT (High tensile strength) carbon fibres based on PAN (polyacrylonitrile) normally have a lattice distance between 0,355 and 360 nm when treated at temperatures around 1400 - 1500 °C.
If such an HT fibre is post heat treated at temperatures around 2500 °C you get an lattice distance which is around 0,345 nm which is still far away from a graphite structure.
HM (High modulus fibres) carbon fibres based on mesophase pitch can reach around 2500 °C a lattice distance of around 0,342 which is also no graphitic lattice distance.
a literature reference you might find at Wilhelm Frohs, University of Karlsruhe (approx. 1988-1990)
there is no difference. In both cases you have a carbon fibre reinforced epoxy resin (CFRP). Sometimes people use the term graphite fibres instead of carbon fibre which is not correct. There doesn't exist a graphite fibre. A graphite modification in common sense has a lattice distance of 0,335 nm.
HT (High tensile strength) carbon fibres based on PAN (polyacrylonitrile) normally have a lattice distance between 0,355 and 360 nm when treated at temperatures around 1400 - 1500 °C.
If such an HT fibre is post heat treated at temperatures around 2500 °C you get an lattice distance which is around 0,345 nm which is still far away from a graphite structure.
HM (High modulus fibres) carbon fibres based on mesophase pitch can reach around 2500 °C a lattice distance of around 0,342 which is also no graphitic lattice distance.
a literature reference you might find at Wilhelm Frohs, University of Karlsruhe (approx. 1988-1990)
can you explain why my composites handbook does distinguish carbon from graphite? for instance, there is a section on "carbon and graphite yarns" which states: "
"Carbon yarns have higher surface area, higher electrical resistivity, and lower carbon assay and density than graphite yarns; the carbon yarns have a tendency to pick up more moisture, are wet with resin more easily, and provide lower-thermal-conductivity yarn-resin composites."
They go on to even distinguish carbon and graphite cloth, graphite-graphite composites, with graphite seemingly being extremely versitile in how it is used as a reinforcement for graphite-metallic alloys as well. Source: "Composite Materials Handbook" - Mel M. Schwartz ISBN: 0-07-055743-8
can you explain why my composites handbook does distinguish carbon from graphite? for instance, there is a section on "carbon and graphite yarns" which states: "
"Carbon yarns have higher surface area, higher electrical resistivity, and lower carbon assay and density than graphite yarns; the carbon yarns have a tendency to pick up more moisture, are wet with resin more easily, and provide lower-thermal-conductivity yarn-resin composites."
They go on to even distinguish carbon and graphite cloth, graphite-graphite composites, with graphite seemingly being extremely versitile in how it is used as a reinforcement for graphite-metallic alloys as well. Source: "Composite Materials Handbook" - Mel M. Schwartz ISBN: 0-07-055743-8
Graphite-epoxy and carbon epoxy composites can be extremely different from a general point of view, as there are indeed a lot of available carbon forms (carbon nanotubes, carbon blacks, short carbon fibres, graphite flakes, graphene, carbon onions, astralenes, etc.), and all these kinds of composites have indeed been already prepared and are still actively investigated. Depending on the kind of carbon and on their volume fraction, very different properties can be obtained. But as far as CFRP are concerned, the difference is less, as they always deal with carbon fibres which can be more or less graphitized, depending on the precursor and on the temperature at which they were prepared. Probably graphite-epoxy composites in this contex tjust means that the corresponding fibres were highly graphitized, that's all. Alain
Graphite-epoxy and carbon epoxy composites can be extremely different from a general point of view, as there are indeed a lot of available carbon forms (carbon nanotubes, carbon blacks, short carbon fibres, graphite flakes, graphene, carbon onions, astralenes, etc.), and all these kinds of composites have indeed been already prepared and are still actively investigated. Depending on the kind of carbon and on their volume fraction, very different properties can be obtained. But as far as CFRP are concerned, the difference is less, as they always deal with carbon fibres which can be more or less graphitized, depending on the precursor and on the temperature at which they were prepared. Probably graphite-epoxy composites in this contex tjust means that the corresponding fibres were highly graphitized, that's all. Alain
Hello, You are right, graphite is a form of carbon. The carbon fibers are not homogeneous and contain a percentage of amorphous carbon and another percentage of graphite, depending of the process used. If the process used a precursor PAN (polyacrylnitril), and if the temperature is higher than 2500°C, the graphite increased. The graphite fibers present a higher Young's modulus, but a lower strain at rupture, they are more brittle.
Hello, You are right, graphite is a form of carbon. The carbon fibers are not homogeneous and contain a percentage of amorphous carbon and another percentage of graphite, depending of the process used. If the process used a precursor PAN (polyacrylnitril), and if the temperature is higher than 2500°C, the graphite increased. The graphite fibers present a higher Young's modulus, but a lower strain at rupture, they are more brittle.
there are a lot of possibilities to create a composite material p.e. based on an epoxy matrix resin and carbon materials with different degree of graphitization (p.e. graphenes, carbon nanutubes, graphite flakes .....)
But: Carbon fibers nether will show a graphite lattice structure independent from their precursor (polyacrylonitrile or mesophase pitch), see attachement. They only form graphite-like sheets with increasing carbonization temperature parallel to the carbon fibre axis .
The resulting carbon structures are far away from a graphite material. So in any case the synonym "Graphite Fiber" is wrong and schould be avoided as well as the synonym "Graphite-Epoxy Composite"
there are a lot of possibilities to create a composite material p.e. based on an epoxy matrix resin and carbon materials with different degree of graphitization (p.e. graphenes, carbon nanutubes, graphite flakes .....)
But: Carbon fibers nether will show a graphite lattice structure independent from their precursor (polyacrylonitrile or mesophase pitch), see attachement. They only form graphite-like sheets with increasing carbonization temperature parallel to the carbon fibre axis .
The resulting carbon structures are far away from a graphite material. So in any case the synonym "Graphite Fiber" is wrong and schould be avoided as well as the synonym "Graphite-Epoxy Composite"
Well graphite is an allotrope of carbon and so one could say that composites made of carbon and graphite are same yet there is a difference. The degree of manufacture is quite different thus exhibit different properties. As such, they two shouldn't be used interchangeably
Well graphite is an allotrope of carbon and so one could say that composites made of carbon and graphite are same yet there is a difference. The degree of manufacture is quite different thus exhibit different properties. As such, they two shouldn't be used interchangeably
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Graphite epoxy polymeric composite: Graphite particulate or Graphite flake is reinforced in epoxy resin matrix.
Carbon epoxy polymeric composite: Carbon fibre having a particular aspect ratio is reinforced in epoxy resin matrix.
Graphite epoxy polymeric composite: Graphite particulate or Graphite flake is reinforced in epoxy resin matrix.
Carbon epoxy polymeric composite: Carbon fibre having a particular aspect ratio is reinforced in epoxy resin matrix.
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Dear Ajit,
there is no difference. In both cases you have a carbon fibre reinforced epoxy resin (CFRP). Sometimes people use the term graphite fibres instead of carbon fibre which is not correct. There doesn't exist a graphite fibre.
A graphite modification in common sense has a lattice distance of 0,335 nm.
HT (High tensile strength) carbon fibres based on PAN (polyacrylonitrile) normally have a lattice distance between 0,355 and 360 nm when treated at temperatures around 1400 - 1500 °C.
If such an HT fibre is post heat treated at temperatures around 2500 °C you get an lattice distance which is around 0,345 nm which is still far away from a graphite structure.
HM (High modulus fibres) carbon fibres based on mesophase pitch can reach around 2500 °C a lattice distance of around 0,342 which is also no graphitic lattice distance.
a literature reference you might find at Wilhelm Frohs, University of Karlsruhe (approx. 1988-1990)
Regards
Michael
Dear Ajit,
there is no difference. In both cases you have a carbon fibre reinforced epoxy resin (CFRP). Sometimes people use the term graphite fibres instead of carbon fibre which is not correct. There doesn't exist a graphite fibre.
A graphite modification in common sense has a lattice distance of 0,335 nm.
HT (High tensile strength) carbon fibres based on PAN (polyacrylonitrile) normally have a lattice distance between 0,355 and 360 nm when treated at temperatures around 1400 - 1500 °C.
If such an HT fibre is post heat treated at temperatures around 2500 °C you get an lattice distance which is around 0,345 nm which is still far away from a graphite structure.
HM (High modulus fibres) carbon fibres based on mesophase pitch can reach around 2500 °C a lattice distance of around 0,342 which is also no graphitic lattice distance.
a literature reference you might find at Wilhelm Frohs, University of Karlsruhe (approx. 1988-1990)
Regards
Michael
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Dear Thoguluva,
are you really sure? Do you have a link to a product using graphite flakes in epoxy?
With best regards
Joachim
Dear Thoguluva,
are you really sure? Do you have a link to a product using graphite flakes in epoxy?
With best regards
Joachim
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Dear Ajit,
there is no difference. In both cases you have a carbon fibre reinforced epoxy resin (CFRP). Sometimes people use the term graphite fibres instead of carbon fibre which is not correct. There doesn't exist a graphite fibre.
A graphite modification in common sense has a lattice distance of 0,335 nm.
HT (High tensile strength) carbon fibres based on PAN (polyacrylonitrile) normally have a lattice distance between 0,355 and 360 nm when treated at temperatures around 1400 - 1500 °C.
If such an HT fibre is post heat treated at temperatures around 2500 °C you get an lattice distance which is around 0,345 nm which is still far away from a graphite structure.
HM (High modulus fibres) carbon fibres based on mesophase pitch can reach around 2500 °C a lattice distance of around 0,342 which is also no graphitic lattice distance.
a literature reference you might find at Wilhelm Frohs, University of Karlsruhe (approx. 1988-1990)
Regards
Michael
Dear Ajit,
there is no difference. In both cases you have a carbon fibre reinforced epoxy resin (CFRP). Sometimes people use the term graphite fibres instead of carbon fibre which is not correct. There doesn't exist a graphite fibre.
A graphite modification in common sense has a lattice distance of 0,335 nm.
HT (High tensile strength) carbon fibres based on PAN (polyacrylonitrile) normally have a lattice distance between 0,355 and 360 nm when treated at temperatures around 1400 - 1500 °C.
If such an HT fibre is post heat treated at temperatures around 2500 °C you get an lattice distance which is around 0,345 nm which is still far away from a graphite structure.
HM (High modulus fibres) carbon fibres based on mesophase pitch can reach around 2500 °C a lattice distance of around 0,342 which is also no graphitic lattice distance.
a literature reference you might find at Wilhelm Frohs, University of Karlsruhe (approx. 1988-1990)
Regards
Michael
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can you explain why my composites handbook does distinguish carbon from graphite? for instance, there is a section on "carbon and graphite yarns" which states: "
"Carbon yarns have higher surface area, higher electrical resistivity, and lower carbon assay and density than graphite yarns; the carbon yarns have a tendency to pick up more moisture, are wet with resin more easily, and provide lower-thermal-conductivity yarn-resin composites."
They go on to even distinguish carbon and graphite cloth, graphite-graphite composites, with graphite seemingly being extremely versitile in how it is used as a reinforcement for graphite-metallic alloys as well.
Source: "Composite Materials Handbook" - Mel M. Schwartz ISBN: 0-07-055743-8
can you explain why my composites handbook does distinguish carbon from graphite? for instance, there is a section on "carbon and graphite yarns" which states: "
"Carbon yarns have higher surface area, higher electrical resistivity, and lower carbon assay and density than graphite yarns; the carbon yarns have a tendency to pick up more moisture, are wet with resin more easily, and provide lower-thermal-conductivity yarn-resin composites."
They go on to even distinguish carbon and graphite cloth, graphite-graphite composites, with graphite seemingly being extremely versitile in how it is used as a reinforcement for graphite-metallic alloys as well.
Source: "Composite Materials Handbook" - Mel M. Schwartz ISBN: 0-07-055743-8
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VOTE
Graphite-epoxy and carbon epoxy composites can be extremely different from a general point of view, as there are indeed a lot of available carbon forms (carbon nanotubes, carbon blacks, short carbon fibres, graphite flakes, graphene, carbon onions, astralenes, etc.), and all these kinds of composites have indeed been already prepared and are still actively investigated. Depending on the kind of carbon and on their volume fraction, very different properties can be obtained.
But as far as CFRP are concerned, the difference is less, as they always deal with carbon fibres which can be more or less graphitized, depending on the precursor and on the temperature at which they were prepared. Probably graphite-epoxy composites in this contex tjust means that the corresponding fibres were highly graphitized, that's all.
Alain
Graphite-epoxy and carbon epoxy composites can be extremely different from a general point of view, as there are indeed a lot of available carbon forms (carbon nanotubes, carbon blacks, short carbon fibres, graphite flakes, graphene, carbon onions, astralenes, etc.), and all these kinds of composites have indeed been already prepared and are still actively investigated. Depending on the kind of carbon and on their volume fraction, very different properties can be obtained.
But as far as CFRP are concerned, the difference is less, as they always deal with carbon fibres which can be more or less graphitized, depending on the precursor and on the temperature at which they were prepared. Probably graphite-epoxy composites in this contex tjust means that the corresponding fibres were highly graphitized, that's all.
Alain
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Hello,
You are right, graphite is a form of carbon. The carbon fibers are not homogeneous and contain a percentage of amorphous carbon and another percentage of graphite, depending of the process used.
If the process used a precursor PAN (polyacrylnitril), and if the temperature is higher than 2500°C, the graphite increased.
The graphite fibers present a higher Young's modulus, but a lower strain at rupture, they are more brittle.
Hello,
You are right, graphite is a form of carbon. The carbon fibers are not homogeneous and contain a percentage of amorphous carbon and another percentage of graphite, depending of the process used.
If the process used a precursor PAN (polyacrylnitril), and if the temperature is higher than 2500°C, the graphite increased.
The graphite fibers present a higher Young's modulus, but a lower strain at rupture, they are more brittle.
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Anyway,...
there are a lot of possibilities to create a composite material p.e. based on an epoxy matrix resin and carbon materials with different degree of graphitization (p.e. graphenes, carbon nanutubes, graphite flakes .....)
But:
Carbon fibers nether will show a graphite lattice structure independent from their precursor (polyacrylonitrile or mesophase pitch), see attachement. They only form graphite-like sheets with increasing carbonization temperature parallel to the carbon fibre axis .
The resulting carbon structures are far away from a graphite material. So in any case the synonym "Graphite Fiber" is wrong and schould be avoided as well as the synonym "Graphite-Epoxy Composite"
Michael
Anyway,...
there are a lot of possibilities to create a composite material p.e. based on an epoxy matrix resin and carbon materials with different degree of graphitization (p.e. graphenes, carbon nanutubes, graphite flakes .....)
But:
Carbon fibers nether will show a graphite lattice structure independent from their precursor (polyacrylonitrile or mesophase pitch), see attachement. They only form graphite-like sheets with increasing carbonization temperature parallel to the carbon fibre axis .
The resulting carbon structures are far away from a graphite material. So in any case the synonym "Graphite Fiber" is wrong and schould be avoided as well as the synonym "Graphite-Epoxy Composite"
Michael
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The term graphite fibers is justified only if three-dimensional crystalline order is confirmed (e.g. by X-ray diffraction measurements).
Ref:
P. Morgan, Carbon fibers and their composites, Taylor & Francis, 2005.
The term graphite fibers is justified only if three-dimensional crystalline order is confirmed (e.g. by X-ray diffraction measurements).
Ref:
P. Morgan, Carbon fibers and their composites, Taylor & Francis, 2005.
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From technical/manufacturers point of view, the difference between graphite and carbon fibers (made from PAN precursor) is as follows:
Carbon fibers are carbonized at ca. 1315°C and contain 93-95% of carbon.
Graphite fibers are carbonized at higher temperature ca. 1900-2480°C and thus contain higher amount of carbon - 99%.
My opinion is in agreement with Michael Heine who gave a full scientific background of the issue.
From technical/manufacturers point of view, the difference between graphite and carbon fibers (made from PAN precursor) is as follows:
Carbon fibers are carbonized at ca. 1315°C and contain 93-95% of carbon.
Graphite fibers are carbonized at higher temperature ca. 1900-2480°C and thus contain higher amount of carbon - 99%.
My opinion is in agreement with Michael Heine who gave a full scientific background of the issue.
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