3D‑Printed Carbon Fiber: A Superior Alternative to Aluminum Amid Global Shortages

Aluminum Shortage Drives Demand for New Materials

Since early 2021, aluminum prices have surged over 50%. Market analysts project this trend will persist for at least the next two years, creating supply constraints across many industries.

According to Jyske Bank, the global shortfall stems from three key drivers: stimulus‑fueled consumer spending, rapid growth in sustainable technologies that rely on aluminum (e.g., wind turbines and electric vehicles), and China’s expanded production and domestic consumption.

Why 3D‑Printed Carbon Fiber is the Logical Replacement

Markforged’s Carbon Fiber technology offers a compelling alternative for components traditionally machined from aluminum. Carbon Fiber boasts the highest strength‑to‑weight ratio among our reinforcing fibers—six times stronger and eighteen times stiffer than Onyx, our short‑fiber composite.

When combined with a Composite Base like Onyx, continuous fiber reinforcement can produce parts that rival the performance of 6061‑T6 aluminum. The material is extremely stiff, strong, and can be automatically printed in complex geometries, enabling optimized, lightweight designs.

What is Carbon Fiber?

Carbon fibers consist of tightly packed carbon atoms forming crystalline strands 5–10 microns in diameter. In production, thousands of these strands are bundled into tows and integrated with thermoplastic or thermoset matrices to create engineering composites.

Key advantages include:

• High stiffness and tensile strength comparable to aluminum
• Significantly lower density than steel and aluminum
• Excellent resistance to heat and chemicals

Carbon Fiber as a Viable Aluminum Substitute

Continuous Fiber Reinforcement (CFR) allows carbon fiber to match aluminum’s strength while adding superior stiffness, impact resistance, heat tolerance, and durability.

CFR offers designers flexibility: you can specify the amount and placement of fiber within a part, tailoring reinforcement to precise load paths.

Carbon Fiber Properties vs. Aluminum

Compared with 6061‑T6 aluminum, 3D‑printed carbon fiber offers a 50% higher strength‑to‑weight ratio in flexure and a 300% increase in tensile performance. It also achieves a flexural strength of 540 MPa, surpassing aluminum’s <480 MPa.

See our comprehensive strength data sheet for detailed measurements.

How 3D Printing with Carbon Fiber Works

Markforged printers first build the outer shell and infill using Onyx— a thermoplastic infused with short‑strand carbon fibers—via fused filament fabrication (FFF). A secondary nozzle then inlays long‑strand CFR, selectively reinforcing perimeters, key features, or entire layers based on load requirements.

Want to Learn More?

Speak with a 3D printing specialist today.

Resources

• Introductory Guide: 3D Printing with Carbon Fiber
• Carbon Fiber Strength Measurements (ASTM)