ScienceDaily: Researchers use 3D printing to create high-performance materials.
Researchers from Sandia National Laboratories discovered that a new 3D printed superalloy could be used to help power plants produce more electricity and less carbon as the world searches for ways to reduce greenhouse gas emissions.
Sandia scientists worked with researchers from 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 machinery. These findings could have wide-ranging impacts on the energy sector, as well as the aerospace industry and automotive industries. They also hint at a new class in similar alloys that are still to be discovered.
Andrew Kustas, Sandia scientist, said that the material can be used to access previously unattainable combinations of high strength and low weight. “We believe that additive manufacturing is a key reason why we were able to achieve this,” Kustas said.
The journal published the findings by the team. Applied Materials Today.
Material that can withstand high heat, which is crucial for power plant turbines
According to the U.S. Energy Information Administration, about 80% of electricity comes from nuclear power plants or fossil fuels. Both types of facilities use heat to turn turbines into electricity. How hot the metal turbine parts can get limits power plant efficiency. A turbine that can operate at higher temperatures can increase its efficiency, while also reducing the amount waste heat released into the environment, said Sal Rodriguez, a Sandia nuclear engineering engineer who did not take part in the research.
Sandia’s experiments demonstrated that the new superalloy, which contains 42% aluminum and 25% titanium, 13% nickel, 8% zirconium and 4% tantalum, was stronger at 800 degrees Celsius (1.472 degrees Fahrenheit). This was in contrast to many high-performance alloys such as those used in turbine parts. It also proved stronger when brought back down to ambient temperature.
Rodriguez stated that this is a win-win situation for both the environment and energy.
These findings could not only benefit energy, but other industries as well. Aerospace researchers are looking for lightweight materials that can withstand high heat. Nic Argibay, a scientist at Ames Lab, said that Sandia and Ames are working with industry to see how alloys such as this could be used for the automotive industry.
“Electronic structure theory, led by Ames Lab, was able to provide an explanation of the atomic origins these useful properties. We are now in the process optimizing this new type of alloys to address manufacturing challenges and scalability problems,” Argibay stated.
This research was supported by the Department of Energy and Sandia’s Laboratory Directed Research and Development program.
Discovery highlights advances in materials science
Additive Manufacturing, also known by 3D printing is a versatile manufacturing method that is energy-efficient. A high-power laser is used to flash-melt materials, usually plastics or metals. This is a common printing method. The printer then deposits the material in layers and builds an object as the molten material cools rapidly.
New research shows how the technology can be repurposed to make new materials. Sandia team members used the 3D printer to quickly melt powdered metals, then print a sample.
Sandia’s creation is also a significant shift in alloy development, as no single metal makes up more that half of the material. Steel is 98% iron, carbon, and other elements.
Kustas stated that “Iron with a pinch of Carbon changed the world.” There are many examples of combining two or three elements to create an engineering alloy. We are now able to combine four or five elements within one material. That’s when it gets really challenging from both a materials science perspective and a metallurgical perspective.
Scalability and cost are two of 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 computer-scale atomic modeling but was not directly involved in the study. “All these metals interact in microscopic, even atomic, levels. These interactions are what determine how strong, malleable, and what their melting point will be. Our model can calculate all this and allow us to predict the performance before we manufacture it.
Kustas acknowledged that there are many challenges ahead. One is that it may be difficult to produce large quantities of the superalloy without microscopic cracks. This is a common challenge in additive manufacturing. He also stated that the alloy is expensive because of the materials used. The alloy might not be suitable for consumer goods, where cost reduction is a priority.
Kustas stated, “With all those caveats it’s possible to scale this and make a bulk of this, it’s an amazing 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, and economic competitiveness. The main facilities are in Albuquerque and Livermore in New Mexico.