Graphite Fiber

Name:
Graphite Fiber
Detailed information:
High-tensile fibers or whiskers made from (1) rayon, (2) polyacrylonitrile, or (3) petroleum pitch.

Properties:

(1) Amorphous structure, oxidizes readily, requiring silicon carbide coating. Resistant to acids and bases, including hydrogen fluoride; tensile strength 50,000–150,000 psi, elastic modulus 4–9 million psi, temperature limit in oxidizing atm 500C, self-lubricating, resistant to electricity, lightweight. (2) Polycrystalline structure, tensile strength up to 350,000 psi, elastic modulus up to 70 million psi, smooth surface, lightweight. (3) Properties similar to (2).

Derivation:

(1) Heating rayon in air at 1400–1700C. (2) Heating polyacrylonitrile in air at 220C (20 h) to oxygenate, then in hydrogen to 1000C (24 h) to carbonize, finally in argon at 2500C (2 h). (3) Heating pitch materials (petroleum residues, asphalt, etc.) to carbonization temperature.

Available Forms:

Filament, yarn, fabric, whiskers. Fibers may be 7–8 microns in diameter.

Use:

Heating pads (combined with glass fiber), protection clothing, polyester and epoxy composites for jet engine components, spacecraft, compressor blades, airframe structure, electrodes for spark-hardening metals, flame-proof textile products, engineering thermoplastics.

See Fiber; Whiskers; Composite; Carbon, Industrial.