When auto racing was in its infancy, engineers considered metals the only materials capable of providing the racing vehicles with the necessary strength and rigidity.
These days, the automotive industry still uses various metals for different purposes. For instance, Formula One cars consist of over 20 aluminum alloys, 30 types of steel, titanium, magnesium, and Inconel. The latter is a heat-resistant nickel-chromium alloy.
In the early 20th century, industries first discovered plastic. It’s cheap, lightweight, and you can create plastic objects of any shape imaginable. On the contrary, one can barely build a plastic car as this material isn’t strong enough.
However, composite materials and carbon-fiber-reinforced polymers bring much more to the table.
They are five times stronger than steel and 70% lighter. Immense strength combined with low weight made them some of the most popular materials in car production.
The History of Carbon Composites
Some composites, such as fiberglass, appeared before carbon fiber. However, these days, engineers usually mean carbon fibers while speaking of composites.
Carbon fiber was invented at Farnborough, Britain, in 1963. Back then, it cost £136 per pound. It would equal £2,272 or $3,082 these days. Today, the carbon fiber price ranges between $7 and $9 per pound. It will continue to drop because the aerospace and automotive industries are increasingly optimizing carbon fiber production.
Although Great Britain was the first country to produce carbon fibers massively, many countries outperformed it. Thus, Japan invested millions of dollars into composite material research that later came in handy for the United States. Once scientists discovered the perspectives of this composite in aerospace and defense industries, its production exploded.
How to Fabricate Carbon Fibers?
There are plenty of composite materials besides carbon fiber. Thus, Formula One cars consist of over 50 composites besides metals. In particular, engineers use 30 carbon-fiber-reinforced composites. Many automotive brands use hundreds of composite materials based on Kevlar or Zylon.
For many years, plastic reinforced with carbon fibers has been the most used composite material. Moreover, carbon fiber producers apply different technologies to make the final product either super-hard or stiff.
First, carbon fibers as thin as one-tenth of the human hair get bundled. Afterward, one must tie up the bundles consisting of 1,000-12,000 fibers. The knotting pattern of fibers determines the final mechanical properties of the fibers, like strength or stiffness.
The simplest pattern consists of unidirectional fibers. As the name suggests, the bundled carbon fibers lie in one direction. It provides maximum strength in that direction. But such fibers can’t resist any perpendicular load. Meanwhile, most composite materials consist of interlaced fibers, which allows such materials to withstand omnidirectional loads.
However, it’s not just the carbon fibers themselves and the way they’re interlaced that give the end product its properties. The base plastic material also matters. It must be durable and heat-resistant. Formula One uses highly durable and heat-resistant plastic in its cars.
How to Produce Carbon Fiber Parts?
One has to apply sophisticated techniques to produce materials for Formula One cars. Check how it works below.
Engineers apply several carbon fiber layers to a specific template (that often consists of carbon fibers as well). It’s called lamination. It’s tricky to apply carbon fibers to a plastic mold by hand, so automotive brands use laser laying machines and other precision devices.
Afterward, these layers are coated with a silk-like substance to remove excess plastic from the template. In the end, the template gets covered in impermeable plastic.
Once lamination is complete, workers place the template in the vacuum chamber to let the fibers stick firmly to the plastic.
Then, they put the template in an autoclave, which is an enormous high-pressure furnace. Under the pressure of eight bars, the fibers compress, and any air gets squeezed. This technology makes the final carbon fiber parts 50% stronger than fiberglass, let alone steel.
Common Pitfalls of Carbon Fiber Fabrication
When assembling carbon fiber parts, you have to ensure they don’t get damaged in the process. It’s not like with steel parts when visual examination does the trick. You can observe the specimen and tell when it’s deformed or cracked.
Meanwhile, you will hardly differentiate between broken and undamaged carbon fiber details due to their multi-layered structure. After all, a seemingly intact carbon fiber part might have a crack somewhere between the first and the fifth layer.
Consequently, it can break in half in the wrong place at the wrong time. That’s why engineers use ultrasound scanners to check each carbon fiber for even the slightest imperfections.
The Future of Carbon Composites
Scientists do their best to make composites as durable as possible. However, they also sweat over plastic production techniques, including novel 3D printing methods, like selective laser sintering.
Furthermore, engineers are improving plastic properties. Thus, recently discovered carbon nanotubes might reshape the current automotive industry.
The Future of Metals in Formula One
Can we expect metal production breakthroughs of the same magnitude? Sure, we can.
Formula One has already been using nanotechnology to reinforce aluminum alloys with silicon and carbon. Steel alloys can still provide much use, as scientists regularly improve steel grades to increase their durability.