Cornell Researchers develop method to control metal microstructure for stronger parts
February 13, 2025
Researchers from Cornell University, Ithaca, New York, have found a way to control the changes in the microstructure of metals during Additive Manufacturing by adjusting alloy composition, said to result in stronger and more reliable metal parts. The findings, published in Nature Communications, provide insight into the phase changes that occur during the metal AM process and could improve materials used for Additive Manufacturing.
“A major problem is that most of the materials we print form column-like structures that can weaken the material in certain directions,” stated senior author Atieh Moridi, assistant professor and an Aref and Manon Lahham Faculty Fellow in the Sibley School of Mechanical and Aerospace Engineering, in Cornell Engineering. “We discovered that by adjusting the composition of the alloys, we can essentially disrupt these column-like structures and make a more uniform material.”
By adjusting the ratio of manganese to iron in their starting material, the team disrupted columnar grain growth, reduced grain size significantly, and enhanced the yield strength of the finished metal.
“Microstructural features, like grain size, are the building blocks that govern material performance and properties” Moridi said. “The material composition controls the phase stability, which was the key for us to control the microstructure.”
The column-like grain structures form and grow in a fraction of a second during the phase change in the manufacturing process, which is why scientists had previously struggled to study this phenomenon, said the study’s first author, Akane Wakai, Ph.D. ‘24.
“The difficult part was trying to resolve these very short spans of time where the material goes from liquid state to solid state,” Wakai shared. This is because the final product retains no trace of its earlier state.
The utilised the Cornell High Energy Synchrotron Source to overcome this issue by obtaining fraction-of-a-second data about their materials during the manufacturing process. In the best-performing sample, Moridi shared, “we found evidence of an intermediate phase that can help disrupt those column-like grains and refine the grain structure.”
Understanding the material properties of the starting alloy and resulting phase changes could establish a new foundation for selecting metals in Additive Manufacturing.
“The findings from this research can be used for real-life applications to create more reliable materials that enable even better performance,” Wakai said. “Not too far into the future, we’ll start seeing 3D printed metal parts, even in consumer products like cars or electronics.”
Improving the reliability of AM metals would significantly benefit the manufacturing industry. Wakai noted that Additive Manufacturing of metal has a “freedom of design that can lead to weight reduction, shortened manufacturing time, minimised material waste, and can create features that are otherwise really difficult or impossible to fabricate through conventional methods.”
Collaborators included researchers from NASA and the University of Pittsburgh. The research was funded by the US Department of Energy, National Science Foundation, and NASA.
