High modulus carbon fibers

High-performance carbon fiber including high-strength carbon fiber, high-modulus carbon fiber, mid-modulus carbon fiber, etc. 

From 1964 to 1975, spurred by the growing awareness of the potential properties of carbon fibers, high-modulus and high-strength carbon fibers from rayon, PAN, and pitch were invented, developed, and commercialized, opening up an explosive growth in the "high performance" composites Industry. 

Structural reinforcement of concrete coltrmrts by carbon fiber high-resistemce/high-modulus fabrics... 

Laying up of carbon fiber high-resistance/high-modulus fabric with factored arranged fibers and later treatment by a special break-bubble roller... 

Reinforcement of masonry vaults realized by carbon fiber high-resistance/high-modulus fabrics Reinforcement of masonry vaults realized by carbon fiber high-resistance/high-modulus fabrics should follow the procedure described below ... 

There are three categories of carbon fibers standard modulus (approximately 250 GPa), intermediate modulus (approximately 300 GPa), and high modulus (above 300 GPa). 

Fibers for spedal applications (high modulus fibers, elastomeric fibers, carbon fibers, high temperature-resistant... 

Carbon and Graphite Fibers. Carbon and graphite fibers (qv) are valued for their unique combination of extremely high modulus and very low specific gravity. Acrylic precursors are made by standard spinning conditions, except that increased stretch orientation is required to produce precursors with higher tenacity and modulus. The first commercially feasible process was developed at the Royal Aircraft Fstablishment (RAF) in collaboration with the acrylic fiber producer, Courtaulds (88). In the RAF process the acrylic precursor is converted to carbon fiber in a two-step process. The use of PAN as a carbon fiber precursor has been reviewed (89,90). 

Fig. 1. Specific strength and Young s modulus of various engineering materials where CF = carbon fiber HM/UHM = high modulus/ultrahigh modulus ...

Carbon fibers are generally typed by precursor such as PAN, pitch, or rayon and classified by tensile modulus and strength. Tensile modulus classes range from low (<240 GPa), to standard (240 GPa), intermediate (280—300 GPa), high (350—500 GPa), and ultrahigh (500—1000 GPa). Typical mechanical and physical properties of commercially available carbon fibers are presented in Table 1. 

Mechanical Properties and Stability at Elevated Temperature. One increasingly important characteristic of carbon fibers is their excellent performance at elevated temperatures. Strength tested in an inert environment remains constant or slightly increases to temperatures exceeding 2500°C. Amoco s high modulus pitch carbon fiber P-50 maintains approximately 80% of room temperature modulus at temperatures up to 1500°C, then decreases more rapidly to 30% at 2800°C (64). The rapid decrease in modulus is a result of increased atomic mobiHty, increa sing fiber plasticity. 

W. Watt, "Chenhstry and Physics of the Conversion of Polyacrylonitrile Fibers into High Modulus Carbon Fibers," in Ref. 6. 

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