Researchers repurpose 3D printing to discover high-performance material — ScienceDaily
Researchers from Sandia National Laboratories discovered that a 3D-printed superalloy can help power plants produce more electricity and less carbon as the world searches for ways to reduce greenhouse gas emissions.
Sandia scientists collaborated with Ames National Laboratory and Iowa State University researchers to create a high performance metal alloy or superalloy. It has a unique composition that makes it stronger, lighter, and more durable than other state-of the-art materials currently used for gas turbine machinery. The findings could have wide-ranging implications for the energy sector and the aerospace and automotive sectors.
Andrew Kustas, Sandia scientist, said that the material has previously unattainable combinations of high strength and low weight. We believe that additive manufacturing is a key reason for our success.
The team published their findings and conclusions in the journal Applied Materials Today.
Material that can withstand high heat is essential for power plant turbines
According to the U.S. Energy Information Administration (USAEIA), about 80% electricity in the United States comes from either nuclear or fossil fuel power plants. Both types of power plants rely on heat to generate electricity. The temperature at which the turbines are heated can affect power plant efficiency. According to Sal Rodriguez, a Sandia nuclear engineer, turbines that can operate at higher temperatures will “convert more energy to electricity while reducing the amount heat that is released into the environment.”
Sandia’s experiments demonstrated that the superalloy, which includes 42% aluminum and 25% titanium, 13% nickel, 8% zirconium and 4-percent tantalum, was stronger at 800 Celsius (1,472 Fahrenheit) than other high-performance alloys such as those used in turbine parts. It also proved stronger when it was brought down to room temperatures.
Rodriguez stated, “This is therefore a win for more economic energy and the environment.”
The findings could also be beneficial to other industries, such as energy. Aerospace scientists are looking for lightweight materials that can withstand high temperatures. Nic Argibay, a scientist at Ames Lab, said that Sandia and Ames are working with industry to see how these alloys could be used in automotive manufacturing.
“Electronic Structure Theory led by Ames Lab was able atomic origins of these useful property and we are now optimizing this new alloy to address manufacturing and scalability issues,” Argibay stated.
This research was funded by the Department of Energy and Sandia’s Laboratory Directed Research and Development Program.
Discovery highlights advances in materials science
3D printing is also known as additive manufacturing. It is a flexible and efficient manufacturing process. Common printing techniques use a high-power laser to flash melt a material. This is usually a plastic or metal. After the molten material cools, and solidifies quickly, the printer deposits it in layers.
New research shows how this technology can be repurposed to make new materials. Sandia team members used 3D printers to quickly melt and print samples of powdered metallic metals.
Sandia’s creation is also a major shift in the development of alloys because no one metal makes up more that half of the material. Steel, on the other hand, is 98% iron and carbon combined with various other elements.
Kustas said, “Iron combined with a pinch carbon changed the world.” There are many examples where two or three elements have been combined to create an engineering alloy. We’re now starting to explore four to five elements or more within one material. That’s when the material science and metallurgical perspectives really start to be interesting and challenging.
Cost and scaleability are the biggest challenges.
Moving forward, the team is interested in exploring whether advanced computer modeling techniques could help researchers discover more members of what could be a new class of high-performance, additive manufacturing-forward superalloys.
“These are extremely complicated mixtures,” said Sandia scientist Michael Chandross. Chandross was an expert in atomic scale computer modeling but was not directly involved with the study. “All these metals interact on the microscopic — even atomic — level. These interactions are what determine how strong a material is, how malleable and how hot it will melt. The model can calculate all of this information and help us predict the performance of new materials before they are made.
Kustas stated that there are still challenges. One is that it may be difficult to make the superalloy in large quantities without microscopic cracks. This is a common challenge in additive manufacturing. The alloy’s materials are also expensive, he said. The alloy may not be suitable for consumer goods where cost is a major concern.
Kustas stated, “With all these caveats, this is scalable, and we can make bulk parts out of this, then it’s a big game changer.”
National Laboratories Sandia National is a multimission laboratory run by National Technology and Engineering Solutions of Sandia LLC. It is a wholly-owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy’s National Nuclear Security Administration. Sandia Labs carries out major research and development activities in nuclear deterrence. They also have responsibilities for global security, defense technologies, economic competitiveness, and energy technologies. The main facilities are in Albuquerque and Livermore in New Mexico.