US scientists develop 3D-printed 6-metal superalloy to improve turbines’ efficiency

Scientists at the US-based Sandia National Laboratory, in collaboration with the Ames National Laboratory, the Iowa State University, and Bruker Corp. used a 3D printer to create a high-performance metal superalloy with an unusual composition that makes it stronger and lighter than modern materials currently used in gas turbine equipment, the Sandia lab announced.

Experiments showed that a new superalloy of 42% aluminum, 25% titanium, 13% niobium, 8% zirconium, 8% molybdenum and 4% tantalum at 800°C (1,472°F) is stronger than many other high performance alloys, including those currently used in turbine parts, and is still stronger when brought back to room temperature.

Why it matters

“We’re showing that this material can access previously unobtainable combinations of high strength, low weight and high-temperature resiliency,” Sandia scientist Andrew Kustas said. “We think part of the reason we achieved this is because of the additive manufacturing approach.”

The material created also represents a fundamental shift in alloy development, as no single metal makes up more than half of the total.

“Iron and a pinch of carbon changed the world,” Andrew said. “We have a lot of examples of where we have combined two or three elements to make a useful engineering alloy. Now, we’re starting to go into four or five or beyond within a single material. And that’s when it really starts to get interesting and challenging from materials science and metallurgical perspectives.”

According to the researchers, density functional theory informed the alloy microstructure and the resultant temperature-insensitive hardness properties. The work was published in the Applied Materials Today journal.

According to the researchers, a number of difficulties still need to be overcome for the practical application of this alloy. For example, producing a new superalloy in large volumes without microscopic cracks can be difficult, which is a common problem in additive manufacturing. In addition, the materials included in the composition of the alloy are expensive, which limits its application.