The U.S. Department of Energy has selected Sebastian Kube, an assistant professor in materials science and engineering at the University of Wisconsin-Madison, to receive a 2025 DOE Office of Science Early Career Research Program award.
The award provides $900,000 in support over five years for outstanding early-career scientists at U.S. academic institutions and DOE national laboratories. The goal of these awards is to stimulate new research that has the potential to deliver the fundamental scientific discoveries and major scientific tools needed to transform our understanding of nature and advance the energy, economic and national security of the United States.
Kube will investigate the kinetics and atomic structure of metallic liquids in the supercooled liquid state and during solidification.
Humans have produced metal objects for millennia. While the processing techniques have significantly evolved from early casting techniques to advanced methods such as 3D additive manufacturing, the first step remains the same: The metal is first melted and mixed at high temperatures before being cooled and solidified.
The exact solidification pathway of a metal has a big impact on the final product and its properties, and understanding this pathway could help in the design and processing of new metals. This includes, for example, understanding how its viscosity evolves and how it forms crystal structures during the cooling process. Measuring these properties and mechanisms is extremely difficult, especially at the atomic scale and at “supercooled temperatures,” or temperatures far below the metal’s melting point.
One property is especially useful in revealing how the molten liquid evolves during cooling: A measurement called “liquid fragility” describes how quickly the melt’s viscosity slows down with decreasing temperature. In his research project, Kube will use the new film inflation method, which he developed at Yale University, to uncover the behavior of liquid fragility across hundreds of metals and alloys.
Combined with a suite of sophisticated tools, from synchrotron diffraction experiments and electron microscopy to molecular dynamics simulation and thermodynamic modeling, Kube and his students will develop a new mechanistic understanding of fragility in metallic liquids, describe the atomic structure, and predict the impact on glass formation and crystallization. Overall, the work will lead to predictive models to enable the targeted synthesis and processing of new specialized materials and alloys with practical applications in electricity generation, energy storage, aerospace and propulsion, and other next-generation technologies.
“Deciphering the complex behavior of metals in the liquid state is one of the great frontiers in current materials physics,” says Kube. “Compared to the solid state, which we have probed in depth for over a century, liquid metals are extraordinarily difficult to study experimentally and model accurately. We are still at the beginning of a long journey that promises the discovery of new physics and materials. We are very grateful for DOE’s support, which puts our team into the position to build a new research program in this field.”