Carbon Black
Description
CARBON BLACK is an industrially manufactured COLLOIDAL CARBON material in the form of spheres and of their fused aggregates with sizes below 1000 nm.
See: COLLOIDAL CARBON.
Notes
CARBON BLACK is a commercial product manufactured by thermal decomposition, including detonation, or by incomplete combustion of carbon hydrogen compounds and has a well‐defined morphology with a minimum content of tars or other extraneous materials.
For historical reasons, however, CARBON BLACK is popularly but incorrectly regarded as a form of SOOT. In fact, in many languages, the same word is used to designate both materials. CARBON BLACK is manufactured under controlled conditions, whereas SOOT is randomly formed. They can be distinguished on the basis of tar, ash content, and impurities.
Attempts in the literature to create a general term, “aciniform carbon,” which would cover both CARBON BLACK and SOOT, are not yet generally accepted.
See: SOOT.
Carbon–Carbon Composite
Description
CARBON–CARBON COMPOSITE is a CARBON FIBER‐reinforced carbon matrix material. The carbon matrix phase is typically formed by solid, liquid, or gaseous pyrolysis of an organic precursor material. The matrix is either GRAPHITIZABLE CARBON or NON‐GRAPHITIZABLE CARBON, and the carbonaceous reinforcement is fibrous in form. The composite may also contain other components in particulate or fibrous forms.
See: CARBON FIBER, GRAPHITIZABLE CARBON, NON‐GRAPHITIZABLE CARBON.
Carbon Cenospheres
Description
CARBON CENOSPHERES are porous to hollow carbonaceous sphere‐like particles (frequently in the size range of a few to several hundreds of micrometer diameter) formed during pyrolysis, also in the course of combustion, of carbonaceous liquid droplets (e.g. heavy fuel) or solid particles (e.g. coal).
Carbon Cloth
Description
CARBON CLOTH is a textile material consisting of CARBON FIBERS oriented at least in two directions.
See: CARBON FIBERS.
Notes
CARBON CLOTH is not necessarily woven.
Carbon Electrode
Description
A CARBON ELECTRODE is an electrode for an electrical application. In its green state it comprises GRANULAR CARBON material bound with PITCH. The GRANULAR CARBON material may be either NEEDLE COKE, fine‐grained or isotropic COKE, or reclaimed GRAPHITE powder. Electrodes for use in steel production can only be manufactured from NEEDLE COKE, and the green electrodes are fired at temperatures above around 2800 K to produce highly graphitic electrodes (GRAPHITE ELECTRODES). The other GRANULAR CARBON materials may be used for aluminum electrodes where the duty is not so severe, and the green electrodes are generally fired to lower temperatures.
See: COKE, GRANULAR CARBON, GRAPHITE, GRAPHITE ELECTRODE5, GRAPHITIC CARBON, GRAPHITIZATION HEAT TREATMENT, ISOTROPIC CARBON, NEEDLE COKE, PITCH.
Notes
In both cases it is essential that the GRANULAR CARBONS and the PITCH binders used in the production of the green electrodes have a low sulfur content as the release of sulfur during the high‐temperature firing can lead to the production of significant porosity.
See: GRANULAR CARBON, PITCH, PUFFING.
Carbon Felt
Description
CARBON FELT is a textile material consisting of, in approximation, randomly oriented and intertwined CARBON FIBERS.
See: CARBON FIBERS.
Notes
CARBON FELTS are usually fabricated by CARBONIZATION of organic felts, but they can also be produced from short CARBON FIBERS.
See: CARBON FIBERS, CARBONIZATION.
Carbon Fiber
Description
CARBON FIBERS are fibers (filaments, tows, yarns, rovings) consisting of at least 92% (mass fraction) CARBON, usually in the NON‐GRAPHITIC stage.
See: CARBON, NON‐GRAPHITIC CARBON.
Notes
CARBON FIBERS are fabricated by pyrolysis of organic precursor fibers or by growth from gaseous hydrocarbons. The use of the term GRAPHITE FIBERS instead of CARBON FIBERS as often observed in literature is incorrect and should be avoided. The term GRAPHITE FIBERS is justified only if three‐dimensional crystalline order is confirmed, e.g. by X‐ray diffraction measurements.
See: GRAPHITE FIBERS.
Carbon Fiber Fabrics
Description
CARBON FIBER FABRICS are woven textile materials made of CARBON FIBERS.
See: CARBON FIBERS.
Carbon Fibers Type HM
Description
CARBON FIBERS TYPE HM (HIGH MODULUS) are CARBON FIBERS with a value of Young’s modulus (tensile modulus) larger than 300 GPa (nearly 30% of the C11 elastic constant of a graphite single crystal).
See: CARBON FIBERS.
Notes
The level of the tensile modulus of CARBON FIBERS is controlled by the degree of preferred orientation of the layer planes in the direction parallel to the fiber axis. C11, the elastic constant of graphite single crystals in the direction of the layer planes, is 1060 ± 20 GPa.
In general, the ratio of tensile strength to tensile modulus is smaller than 1 × 10−2 for CARBON FIBERS TYPE HM (but the tensile strength is influenced by flaws in the fibers and may be improved in the future).
CARBON FIBERS TYPE UHM (ULTRAHIGH MODULUS) have moduli of elasticity in excess of 600 GPa, surpassing 50% of the theoretical C11 number. Such high values of Young’s modulus can be achieved most readily in MESOPHASE PITCH‐BASED CARBON FIBERS (MPP‐BASED