How is Carbon Fiber Used in Automobiles?

A profoundly futuristic material, carbon fiber has been the staple material for performance cars for quite some time. It has been used in automobile manufacturing ever since the 1970s, with Mitsubishi pioneering the fabric. But the material is also widely utilized in aviation, spacecraft, the military field, civil engineering, and all kinds of sports. The question is, why is carbon fiber so popular and downright important?


McLaren Senna Carbon
McLaren is a major user of carbon fiber material.

To understand the difference, we must first grasp how steel and metals work in terms of material resistance. All metals behave the same, regardless of what kind of action they must withstand. Even if we stretch them, compress them, twist them, or anything along those lines, they behave mostly the same. Some metals will be stronger than others, while some sorts of metals act somewhat differently than others. This makes them incredibly versatile, while also being easy to work with.

Carbon Fiber Fabric

Carbon fiber doesn’t behave such as steel or other metals. As the name suggests, they are a fabric, or more simply put, a minuscule wire that’s woven into a fabric. This material is extremely strong along the wire’s direction, surpassing steel by a significant margin, even if we stretch them or pull them. However, if we push them on their side, or if we twist them, they are pitifully weak, so much so that specific cardboards might even be tougher than them.

To counteract this massive downside, they are immersed into a resin, called a matrix, that is usually some sort of epoxy. We cannot use just carbon fibers, because any sort of tug in the wrong direction will break the wires. Thus, naming the material “carbon fiber” is a bit misleading, the proper name being “carbon fiber composite.” Composite materials aren’t anything new by any stretch of the imagination. Cavemen built their homes out of wood or wheat strands and mud, with the former being the wire and the latter being the matrix. This matrix allows them to work along their suboptimal direction as well.

Carbon Fiber Composite

Moreover, another significant property of carbon fiber composite is that it’s a lightweight material, lighter than aluminum and a bunch of different metals. As such, with proper engineering, we can carefully pick and choose components that are not only heavy, but that also are only stressed in a singular direction. If they aren’t structural, they might be quite large, and designing these components out of carbon fiber composite might save tens or even hundreds of pounds in the final product.

With these in mind, we can now maybe understand why several parts are made from carbon fiber composite and why some won’t ever be. Koenigsegg makes their rims out of carbon fiber because the weight of the car pushes on the ground directly downwards; thus, those wheels will see mostly compression under the car’s weight, allowing us to point the carbon fiber wires directly towards the ground. The result will be strong and light wheels.

Composite Body Panels

Body panels can be manufactured out of carbon fiber composite, such as hoods, roofs, bumpers, and the like, making them strong enough in case of a crash but lightweight enough that the final car will be significantly lighter. The McLaren Senna Carbon is almost 400 pounds lighter than its regular counterpart, which for a car that weighs under 3,000 pounds is massive. Carbon fiber composite panels aren’t only reserved for the fastest cars out there. BMW, Toyota, Subaru, and several other manufacturers use carbon fiber composite materials too. Toyota, for example, uses carbon fiber composite extensively in their Fuel Cell Electric Vehicle, the Toyota Mirai, to manufacture the hydrogen tanks.

However, not all is rosy with carbon fiber. Its biggest drawback thus far is the material cost. Carbon fiber wires are incredibly thin, much thinner than even a strand of hair. Thus, making any component will be incredibly expensive because you will need a significant coil of wire just to create a simple part. A few parts will surpass thousands of dollars. As a definite price, on average one pound of carbon fiber is a bit over $10, while one pound of simple spring steel is $0.36. If we also take into consideration manufacturing costs because carbon fiber composite materials are difficult to work with, we can observe how the price can become quite steep.

Versatile Carbon Fiber

Carbon fiber is incredibly useful and versatile material. We can develop and push motorsports to their maximum, while also allowing us to improve regular commodities such as airplanes. Moreover, it can also permit some athletes to perform to the next level, in sports such as tennis or hockey. If we manage to manufacture them more affordably, we might notice significant improvements in regular cars too, be it from a safety point of view or a fuel economy point of view.


References


Gay, D., Hoa, S. V., & Tsai, S. W. (2003). Composites Materials: Design and Applications (1st ed.). CRC Press.

2019 McLaren Senna Carbon Specifications. The Car Guide.

THE DRIVE. (2014, April 22). Making 280mph Capable Carbon Fiber Wheels – /INSIDE KOENIGSEGG [Video]. YouTube.


See Also10 Things We Hate About Cars


Photo Attribution


Photo by Ishan Kulshrestha via Pexels.

Photo by Yoshi via Pexels.

Cristian Puscasu
Author: Cristian Puscasu
Cristian Pușcașu started loving cars and wanted to become a “racing driver” thanks to some computer game that lit the fire almost two decades ago. Since then, he came to his senses and decided that becoming an automotive engineer is more sensible, and pursued such a degree in his home country, Romania. Cristian decided to try writing about what he learned, in an attempt to correct certain misconceptions and to use his degree a bit unconventionally.

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