Carbon Fiber VS Steel: Which Is Stronger?

The next time you come up with a great idea, think about designing the product in carbon fiber. Not only will your carbon fiber part look amazing, but it will be amazingly strong for its weight. What makes carbon fiber so strong? Keep reading to find out.

What is Carbon Fiber?

Carbon fiber is composed of carbon, a naturally occurring element, and has high tensile strength and stiffness due to its crystalline structure. It is used to fabricate high-strength, lightweight composite parts with the fiber embedded in a polymer matrix. The physics of carbon makes these parts very strong and incredibly rigid.

Carbon fiber has exceptionally high tensile stiffness. The modulus of elasticity (a measurement of a material’s resistance to deformation) for carbon fibers is between 150-760 gigapascals (GPa). The wide range is because the manufacturing process for carbon fiber can be modified to tailor stiffness and strength. Although many materials, including steel, can have high stiffness and tensile strength, the real benefits of carbon fiber are its strength-to-weight ratio and stiffness-to-weight ratio due to its low density (around 1.8 g/ cm3). As such, it is an ideal candidate for industrial applications such as:

• Robotics
• Metrology
• Terrestrial vehicles
  • cars
  • trucks
  • bikes
• Wind turbines
• Aircraft
• Aerospace structures

In many of these applications, heavier materials consume more energy, increase the loads on actuators and bearings leading to shorter life cycles, and make high-performance designs difficult to achieve.

Bonds and Structure

When you think of carbon, you usually think of pencil “lead.”That’s the brittle material that’s soft enough to write on a page. However, carbon fiber is another form of carbon that is much stronger than its pencil counterpart. Carbon fiber is made from carbon atoms joined together in a chain-like pattern. The long, tightly interlocked chains of carbon atoms in the microscopic crystalline structure provide the strength of carbon fiber that becomes apparent when the fibers are supported in an epoxy matrix.

There are two primary precursors used to make carbon fiber, polyacrylonitrile (PAN) and pitch, but PAN is the most common.

Carbon Fiber is Stiff

Its tightly bonded crystalline structure makes carbon fiber a stiff material. This makes it difficult to misshape so it can be used in a variety of applications. Whether your carbon fiber design is used in simple electronics or is built to strengthen an airplane, your carbon fiber project will retain the rigidity necessary in your lightweight structure.

Carbon Fiber vs. Steel: Which Is Stronger?

Steel has long been used to create sturdy, long-lasting, rigid structures. Carbon fiber is a relatively recent addition to structural materials, but its properties are impressive and unique. The following is a breakdown of the properties of these two materials and some examples of industries that are moving to carbon fiber.

How Does Steel Compare?

Steel has been a go-to material for a long time because of its high modulus of elasticity of around 200 GPa. This rigidity, and its relative abundance, have made it a ubiquitous material for manufacturing. But at a density of about 8 g/cm³ its weight can be very taxing on the machines it is meant to strengthen. This is about 5 times the weight of carbon fiber materials that would provide the same rigidity or better.

What Are Some Common Applications of Carbon Fiber?

Carbon fiber can be used to produce a wide variety of products. Anything that needs to be rigid and lightweight is a perfect candidate for carbon fiber composite materials. They’re popular options for phone cases since they offer great levels of protection from damage. They are being used increasingly in drones and unmanned aerial vehicles (UAVs) where the low weight contributes to a lighter structure and greater payload. In the automobile industry, new advancements in carbon fiber technology have the potential to cut the car’s weight nearly in half.

Also, carbon fiber doesn’t suffer from the thermal expansion of common metals like steel or aluminum. Medical imaging tables benefit from carbon fiber’s strength and stiffness, maintaining critical dimensions under load without breaking down over time, even after high doses of x-ray and gamma radiation.

How Easy is Carbon Fiber to Cut Compared to Steel?

Carbon fiber is easier to cut than steel. Its low weight facilitates handling and Rotary wheels or saws with diamond or tungsten-carbide blades easily cut carbon fiber composite and make fabrication easy.

While steel is a reliable material, the constant advancements in carbon fiber manufacturing make this material an ever-evolving source of innovation. Design a carbon fiber prototype with Element 6 Composites and bring your design to life.