North Carolina State University researchers use eggshells to strengthen magnesium alloys

Researchers at North Carolina State University have developed a method to strengthen magnesium alloys by incorporating finely ground eggshells directly into the manufacturing process. Because eggshells are approximately 95 percent calcium carbonate, they serve as an effective calcium source to improve the mechanical properties of the metal.

This technique, known as friction stir extrusion, uses pressure, friction, and heat to mix the eggshell powder into a magnesium block. This process converts the calcium carbonate into calcium oxide and reactive calcium, creating compounds like Mg₂Ca that reinforce the alloy.

By using eggshell waste, manufacturers can bypass the energy-intensive and complex steps required to extract and process calcium from mined ores. This approach offers a more sustainable, inexpensive, and less energy-intensive supply chain for producing high-strength, lightweight magnesium alloys used in the automotive, aerospace, and biomedical industries.