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 worked with Ames National Laboratory, Iowa State University, and Bruker Corp. to create a superalloy or high-performance metal alloy. This unusual composition makes it stronger than the state-of-the art materials used in gas turbine machines. The findings could have large-scale impacts in the energy and aerospace industries as well as in the automotive and automotive industries.
Andrew Kustas, Sandia scientist, said that the material has previously unattainable combinations of high strength and low weight. “We believe the additive manufacturing approach is part of why we were able to achieve this,” Kustas said.
The journal published the findings of the team. 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 facilities use heat to turn turbines into electricity. How hot the metal turbine parts are can limit 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 released into the environment.”
Sandia’s experiments demonstrated that the new superalloy, which contains 42% aluminum and 25% titanium, 13% nickel, 8% zirconium and 4-percent tantalum, was stronger at 800° Celsius (1.472° F) than other high-performance alloys such as those used in turbine parts. It also proved stronger when it was returned to room temperature.
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 researchers are seeking lightweight materials that resist high heat. Nic Argibay from Ames Lab said that Sandia is collaborating with the industry to investigate how alloys such as this might be used for automotive applications.
“Electronic structure theory, led by Ames Lab, was able to provide an explanation of the atomic origins these useful properties. We are now in process of optimizing the new class of alloys for manufacturing and scalability problems,” Argibay explained.
The research was supported by the Department of Energy and Sandia’s Laboratory Directed Research and Development (LDR&D) program.
Discovery highlights the changes 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 metal or plastic. As the molten material cools rapidly, the printer layers it and builds an object.
New research shows how this technology can also 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 stated, “Iron and some pinch of carbon changed our 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 or five elements or more within one material. This is when things get really interesting and challenging in materials science and metallurgical perspective.
Scalability and cost are two of the greatest 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. Because it can calculate all this and allow us to predict how a new material will perform before it is manufactured, our model takes much of the guesswork out metallurgy.
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. This means that the alloy may not be used in consumer goods, where cost reduction is a priority.
Kustas stated that despite all the caveats, Kustas believes that if this can be scaled and we can make a large part of it, it will be a 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.
