Why is carbon fiber so expensive?
2 Answers
Because carbon fiber offers numerous advantages, as detailed below: 1. High-performance carbon fiber possesses a series of irreplaceable superior properties, including being lightweight, high strength, high modulus, high-temperature resistance, corrosion resistance, erosion and splash resistance, as well as excellent designability and composability. 2. Lightweight: The most obvious benefit of applying carbon fiber to automobiles is vehicle lightweighting, which directly improves energy efficiency, acceleration, and braking performance. Generally, a 10% reduction in vehicle weight leads to a 6% to 8% decrease in fuel consumption, a 5% to 6% reduction in emissions, an 8% to 10% improvement in 0-100km/h acceleration, and a 2m to 7m shorter braking distance. 3. Safety: Lightweighting the body lowers the vehicle's center of gravity, enhancing handling stability and making the vehicle safer and more stable during operation. Carbon fiber composites have excellent energy absorption rates, with crash energy absorption capabilities six to seven times that of steel and three to four times that of aluminum, further ensuring vehicle safety. 4. Comfort: Carbon fiber composites have higher vibration damping; light alloys take 9 seconds to stop vibrating, while carbon fiber composites stop in just 2 seconds. 5. Reliability: Carbon fiber composites exhibit higher fatigue strength. The fatigue strength of steel and aluminum is 30-50% of their tensile strength, whereas carbon fiber composites can reach 70-80%, significantly improving material fatigue reliability in automotive applications. 6. Enhancing body development: Due to carbon fiber composites' superior designability compared to metals, they facilitate the platformization, modularization, and integration of body development. This allows for a hybrid body structure combining carbon fiber and metal platforms, which can achieve modularity and integration, greatly reducing the number of parts, lowering tooling investment, and shortening development cycles compared to traditional automotive body structures.
I've been in materials research for many years, and the high cost of carbon fiber lies in its expensive production process. Starting from extracting polyacrylonitrile fiber from petroleum, it first undergoes pre-oxidation treatment at 300 degrees, then gets baked in a carbonization furnace at over a thousand degrees for several hours. The entire set of equipment easily costs hundreds of millions, not to mention the workshop must maintain constant temperature and humidity, without even a speck of dust. The raw fibers that are finally produced then need to be impregnated with epoxy resin to form composite materials, with the entire layering process done manually without any errors. Most crucially, the yield rate is particularly low - if the temperature isn't controlled just right, the entire batch has to be scrapped. With all this hassle, the costs simply can't be reduced, so the high selling price is completely justified.
