Pyrograf-I is a vapor-grown carbon fiber (VGCF) produced via a fixed catalyst method. Pyrograf-I fibers have a diameter range of 3-20 microns, and a length range of 1-10 cm.
VGCF has been studied worldwide by a number of investigators and has been described in the carbon literature for the last thirty years. An excellent overview of research performed on VGCF and comparison to conventional carbon fibers is available in Graphite Fibers and Filaments. A table of the physical properties of Pyrograf-I before and after heat treatment is shown below. After heat treatment Pyrograf-I provides exceptional thermal conductivity.
Pyrograf I provides exceptional thermal conductivity, approaching the theoretical value of graphite, making it ideally suited to the most demanding thermal management applications.
|Property||As Grown||Heat Treated||Units|
|Fiber Diameter||3 to 20||3 to 20||microns|
|Coefficient of Thermal Expansion||-1.0||ppm/oC|
The key attributes of Pyrograf-I composites are not only their superior thermal conductivity, but their low density for a very high mass specific thermal conductivity. This metric is especially critical for weight sensitive applications such as aircraft and satellites.
VGCF is produced in a catalytic process from hydrocarbon gas. The purity of the carbon source and the mechanics of growth result in a highly graphitic fiber with physical properties approaching those of single-crystal graphite. The enhanced mechanical properties may enable engineered composites to be considered where previously only structural metals or advanced composites could be contemplated.
Owing to the very high thermal conductivity of Pyrograf-I, the material is solely used for thermal management applications. Whether the material is incorporated into carbon-carbon composites, metal matrix composites, or polymer composites, Pyrograf-I can significantly enhance the thermal conductivity of the composite system it is used in. Applications for Pyograf-I include heat-spreaders for consumer electronics, aircraft, and aerospace platforms, as well as integrated gate bipolar transistors for automobiles.
Contact Andy Palmer to discuss your thermal management project.
Mr. Andrew Palmer is a skilled Chemist directly involved in the majority of the contract work ASI performs for its clients. Andy is well versed in the production of ASI’s Pyrograf-I vapor grown carbon fiber and its derivative products for use in thermal management applications. He also has extensive experience in the fabrication of composite materials based upon ASI’s carbon nanofiber product lines. Andy works within a multi-disciplinary team of scientists and engineers to develop new products and materials to meet your thermal management needs.
. M.S. Dresselhaus, G. Dresselhaus, K. Sugihara, I.L. Spain, H.A. Goldberg, Graphite Fibers and Filaments, Springer-Verlag, New York (1988).