MIT Engineers Develop Revolutionary 3D-Printable Aluminum Alloy

In a significant advancement for materials science and manufacturing, engineers at the Massachusetts Institute of Technology (MIT) have developed a 3D-printable aluminum alloy that is five times stronger than conventional aluminum and can withstand temperatures up to 400 degrees Celsius. This breakthrough, achieved through the integration of machine learning in alloy design, holds promise for revolutionizing industries reliant on high-performance materials.

By leveraging machine learning algorithms, the MIT team efficiently identified an optimal combination of aluminum and other elements, resulting in an alloy with exceptional strength and thermal stability suitable for additive manufacturing. This innovation paves the way for producing lighter, more durable components in sectors such as aerospace and automotive engineering.

The project originated from a 2020 MIT course led by Professor Greg Olson, where students were challenged to design a stronger printable aluminum alloy. Traditional simulation methods proved insufficient due to the complexity of material properties. To overcome this, the team employed machine learning techniques to efficiently analyze potential material combinations. By evaluating only 40 compositions—significantly fewer than the over one million combinations typically required—they identified an optimal mix of aluminum and other elements.

The new alloy exhibits a high volume fraction of small precipitates, contributing to its enhanced strength, surpassing previous benchmarks, including the wrought Al 7075 alloy. Produced via laser powder bed fusion (LPBF) 3D printing, the alloy benefits from rapid solidification that prevents precipitate growth, resulting in superior mechanical properties. After aging at 400 degrees Celsius for eight hours, the alloy achieves a tensile strength of 395 megapascals at room temperature, about 50% stronger than the best-known printable aluminum alloys.

The researchers anticipate that this printable aluminum could be utilized to manufacture stronger, more lightweight, and temperature-resistant products, such as fan blades in jet engines. Traditionally, fan blades are cast from titanium—a material that is more than 50% heavier and up to 10 times costlier than aluminum—or made from advanced composites. The adoption of this new alloy could lead to significant energy savings in the transportation industry.

This development aligns with ongoing efforts to enhance the properties of 3D-printed metals. For instance, researchers at the National Institute of Standards and Technology (NIST) discovered that incorporating quasicrystals into 3D-printed aluminum alloys can increase their strength, making them suitable for lightweight, high-strength applications such as airplane parts.

"If we can use lighter, high-strength material, this would save a considerable amount of energy for the transportation industry," said Mohadeseh Taheri-Mousavi, who led the work as a postdoc at MIT and is now an assistant professor at Carnegie Mellon University.

"Because 3D printing can produce complex geometries, save material, and enable unique designs, we see this printable alloy as something that could also be used in advanced vacuum pumps, high-end automobiles, and cooling devices for data centers," added John Hart, the Class of 1922 Professor and head of the Department of Mechanical Engineering at MIT.