Carbon fiber has received quite a bit of attention lately, primarily due to its extensive use in Boeing’s high-tech, lighter weight 787 Dreamliner airplanes. But most Americans likely will experience this modern material in a more down-to-earth vehicle, now that automakers increasingly are turning to carbon fiber when planning and building new cars.
Some recent examples:
* The Chevrolet Corvette Stingray’s roof and hood are made with carbon fiber.
* BMW uses the material to make the passenger frame of its high production i3 electric car.
* Ford has partnered with The Dow Chemical Company to create more car parts using carbon fiber.
Beyond autos and aerospace, carbon fiber already is used to make sporting goods, wind energy turbines, military equipment, America’s Cup racing boats and more. It’s said to be up to 10 times stronger than steel yet four times lighter. And its use is expected to double or even triple by 2020.
So ... just what is carbon fiber? And why should American car drivers (and passengers) care?
Made mostly of carbon atoms, carbon fiber is an incredibly small diameter fiber, usually between 5 and 10 microns across (a micron is a millionth of a meter or about 0.000039 inches). These fibers are bundled to form thread that often is woven into a fabric.
We all learned in chemistry class that a diamond—one of the hardest natural substances—is composed of carbon atoms arranged in a particular lattice. So it’s not surprising that carbon fiber is stiff, strong and light, plus resistant to chemicals and tolerant of high temperatures. It sounds ideal for making stuff.
In fact, on its own, carbon fiber often is not ideal. It usually needs to be combined with other materials to provide the properties needed for a racecar chassis or airplane fuselage or prosthetic limb or tennis racket or fishing rod or bicycle frame.
Combined with what other materials? Typically plastics.
The term “carbon fiber” when used in layman terms most often refers to “carbon-fiber-reinforced plastics” - that is, a composite made up of carbon fibers plus some type of plastic. Or some combination of plastics and perhaps some other materials. Since “carbon-fiber-reinforced plastics” is a mouthful, many people simply shorten it to: “carbon fiber” or “carbon fiber composite.” And the “plastics” get forgotten.
Combining carbon fiber with plastics is sort of like adding rebar (“reinforcing bar”) to concrete, which creates “reinforced concrete.” The combination of carbon fiber and plastics results in materials with superior qualities, including exceptional strength and durability.
As mentioned above, new cars likely will see rapid growth in the use of carbon-fiber-reinforced plastics (often abbreviated CFRP). To date, CFRP auto components—chassis, spoilers, roofs, hoods and many internal and external parts—largely have been employed in higher-end luxury or performance cars due to high manufacturing costs. Today many automakers (e.g., Ford, Mercedes, General Motors, BMW) are investing heavily in CFRP applications, now that costs are coming down and new technologies allow these components to be produced more quickly.
So ... why should we care? Because increased use of CFRP can reduce vehicle weight, improve fuel economy and contribute to safety.
* Weight/fuel economy: As noted above, CFRP is much stronger than steel yet lighter, so car components can be made lighter. That’s one reason behind the Ford and Dow partnership—to help reduce auto weight 750 pounds by 2020. Just a 10 percent reduction in vehicle weight can increase fuel efficiency 6 to 8 percent over the life of today’s cars.
* Safety: CFRP auto components can have a higher “energy-absorption” rate than steel, which can contribute to improved safety in a collision. High-speed racecars, for example, today are made largely with CFRP, which has led to reduced weight, improved performance—and enhanced safety. Like other safety advances developed for the racetrack, CFRP components now are headed toward mainstream use in the family car.
This marriage of carbon fiber and plastics already has contributed to advances in products as diverse as motorcycles, laptops and helicopters. Based on research and development by automakers, it now appears poised to contribute to our next commute.