No. 18 - Carbon Fiber

The pioneering efforts of Union Carbide scientists Roger Bacon and Leonard Singer led to the development of carbon fiber in 1963. The discovery opened the door for designers and engineers to create parts with unmatched stiffness and strength per pound in military aircraft, aerospace, automotive, and sporting goods.

Union Carbide’s Par ma, Ohio, technical center (now GrafTech International) was the focal point of that firm’s carbon-fiber research effort. There, Bacon in 1958 demonstrated the ultra-high strength of graphite in filament form. Seven years later, continuously processed high-performance carbon yarn, made from a rayon precursor, was commercialized. In 1970, Singer produced truly graphitic fibers, leading to the commercialization of carbon yarn derived from liquid crystalline pitch.

In the 1960s, developers of military aircraft raced to use these new stiff, high-strength, lightweight reinforcement materials. Until then, the only available reinforcement was glass, although boron fibers were also coming on the scene. The Cold War fueled a heavy defense buildup and there was considerable focus on developing high-strength, lightweight materials for higher-performing aircraft. Defense contractor Grumman, led by chief materials engineer George Lubin, was at the forefront of bringing carbon-fiber composites into commercial use in military aircraft.

In the mid-1960s, a range of graphite-reinforced epoxy composite parts such as wing tips, nose cones, tail caps, trailing edges of wings, and air-inlet ducts were developed for military jets such as Lockheed’s F-104 Star fighter, LTV Aerospace’s A-7A Corsair II, Grumman’s W2F-Hawkeye (with a carbon-fiber propeller), and the Phantom F4. These materials were also used later in full stabilizer bars and wings for the F-14 TomCat, built in 1967 and believed to be one of the most carbon composite-intensive fighter planes at the time.

Carbon-reinforced composites were also used on window frames and exterior panels for NASA’s later Apollo space capsules, as well as positioning brackets for the lunar excursion module. These materials were typically 40% graphite, 20% boron fiber, and 40% epoxy.

The commercial aircraft industry followed aerospace’s lead and began using carbon fiber in the mid-1970s. Boeing led the charge with its 727 jet, and other aircraft manufacturers soon followed.

Since its invention, carbon fiber has been burdened by its high manufacturing cost, which resulted in limited use in mass-produced cars. In the 1970s, the material was used in truck axles and won extensive use in racing cars (Formula One and Indy), concept cars, luxury vehicles, and high-end sports cars like GM’s Corvette.

Today, carbon-fiber composites enjoy strong growth, bolstered by the decision by Boeing to make extensive use of these materials in its newest aircraft, the 787 Dreamliner, due in 2007.

Though still a small market, consumer products made of carbon-fiber composites have seen growth in bicycles, fishing rods, golf clubs, and tennis rackets. And recently, there has been increased use in high-end cars like the Maybach 57S, Porsche GT, and BMW M6 coupe and in accessories for lower-priced cars.