LLNL’s computationally designed alloys capture best paper of the year award

Lawrence Livermore National Laboratory (LLNL) researchers have been recognized with the Journal of Alloys and Compounds’ 2024 best paper award for their publication, “Microstructural, phase, and thermophysical stability of CrMoNbV refractory multi-principal element alloys.”

The paper examines alloys that have the potential to operate at high temperatures, a feature that enables more efficient engines and mitigates greenhouse gas emission.

“Critical applications in aerospace, energy, and power generation require operating at higher temperatures to achieve higher efficiencies with less fossil fuel,” said LLNL researcher and paper author Jibril Shittu. “Ultimately, with improved alloys, we can reduce the carbon footprint of each of these sectors.”

Current alloys struggle to withstand temperatures over 1000 degrees Celsius (C) while maintaining their structural integrity. Ceramic materials can handle the heat, but they are brittle and difficult to engineer.

To address these challenges, the team examined refractory multi-principal element alloys, specifically mixtures of chromium, molybdenum, niobium and vanadium. For this class of metals, survivability at high temperatures depends on their microstructural and thermophysical stabilities.

Using LLNL’s Materials Acceleration Platform, a computational framework, the scientists narrowed the field of possibilities from 4.6 million to three testable options. They measured mechanical strength and other features of the alloys at a range of high temperatures.

However, testing these properties is not an easy feat. Furnaces and other equipment are mostly developed for superalloys that melt at about 1000–1200 C. This required the authors to redesign and stand up capabilities that were previously nonexistent.  

Although one of the alloys showed exceptional strength above 1000 C, another performed even better.

“Cr₇Mo₁₈Nb₃₅V₄₀ maintains microstructural, phase, and thermophysical stability at all relevant operating temperatures needed to satisfy high-temperature stability and survivability,” said Shittu. “This result highlights the need for high-temperature stability and survivability of alloys over exceptional strength as a design criterion.”

This award-winning publication demonstrates that LLNL’s computational framework can be used to identify viable new alloys for any tailored application. Such a capability cuts alloy discovery and validation time from years to months.

“The strength of our science at LLNL lies in collaboration, by pooling diverse skill sets and perspectives,” said Shittu. “Making a significant research impact of this nature can only be realized by bringing the unique experience and expertise of every team member to the table for a comprehensive and well-rounded solution. This success is truly a team effort.”

This work was supported by LLNL’s Laboratory Directed Research and Development program (22-SI-007).