Replacing Aluminum Parts with 3D-Printed Carbon Fiber

Recently, countries around the world are facing a major shortage of aluminum that began at the start of the pandemic, which has led to steep price increases in aluminum. Since January 2021, aluminum prices have shot up by over 50%, and experts project the prices are expected to rise more in 2022 due to limited supply and high production costs.

According to Jyske Bank, the worldwide aluminum shortage can be traced back to usual suspects of labor shortages, the pandemic, and the ongoing supply chain crisis. It has also been on an upswing due to increased spending on consumer goods due to stimulus packages and increased investments in sustainable technology that rely on the use of aluminum (such as wind turbines, electric cars) and Chinese production and consumption of aluminum.

In light of this aluminum shortage, Markforged Carbon Fiber offers a suitable alternative, as many of our customers use it to replace parts made out of machined aluminum. Carbon Fiber has the highest strength-to-weight ratio of Markforged reinforcing fibers. Six times stronger and eighteen times stiffer than Onyx, Carbon Fiber reinforcement is commonly used for parts that replace machined aluminum.

What is Carbon Fiber?

Carbon fiber is made up of carbon atoms organized into thin, strong crystalline filaments just 5-10 microns in diameter. In modern manufacturing, several thousand carbon fiber are bundled into tows and combined with other materials to form a composite.

When joined with a thermoplastic or thermoset resin matrix, carbon fiber tows can take various forms for use in engineering applications.

Carbon fiber's specific material properties make it ideal for a wide variety of applications, which include:

• • High stiffness and tensile strength (as strong as aluminum)
• • Far lower relative density than steel and aluminum
• • Resistance to heat and chemicals

What makes Carbon Fiber an ideal replacement for aluminum?

Using Continuous Fiber Reinforcement (CFR), carbon fiber can achieve a similar strength to aluminum, with the ability to replace machined components in application. This is due to its enhanced stiffness, impact resistance, heat resistance, and durability.

CFR allows flexibility in how users can implement continuous fibers in their parts - users can control how much carbon fiber is inserted into parts, as well as where specifically in the parts the carbon fiber tows are placed.

Carbon Fiber properties

Compared with 6061 aluminum, 3D printed carbon fiber has a 50% higher strength-to-weight ratio in flexure, and a 300% higher ratio in a tensile moment. Carbon fiber continuous reinforcement has been used to create conformal jigs/fixtures and specialty tooling for some of the largest and most prestigious global business through to one-off end-use parts for high-end motorsport applications.

Furthermore, reinforced Carbon Fiber has a flexural strength of 540 MPa, compared to 6061-T6 aluminum (480 MPa).

Click here for a comprehensive rundown of Carbon Fiber strength measurements.