Radiation exposure may transform alloy resiliency

Researchers from the Department of Materials Science and Engineering at The Grainger College of Engineering, University of Illinois Urbana-Champaign, have found continuous irradiation can improve the resiliency of metal alloys instead of damaging them — a discovery that could transform the design and selection of materials for nuclear reactors and space applications. U. of I. faculty involved in this paper, which was published in Nature's Communications Materials in March 2025, include Assistant Professor Marie Charpagne, Professor Emeritus Robert Averback and Donald W. Hamer Professor Pascal Bellon. 

Why it matters

Most metals deteriorate when bombarded with radiation, but this team discovered that some polycrystalline alloys self-heal through reorganization of their internal microstructure under sustained radiation. In nuclear reactors and outer space applications, metals can spend long periods of time in conditions far from equilibrium, and this research promises improved resistance to the exposure such materials might encounter.

By the numbers

• The research team irradiated alloys with ion beams to damage levels of 30 displacements per atom (dpa) at 75°C, simulating extreme radiation environments
• The self-healing patterns formed at the nanoscale (particles 4-9 nanometers in size)
• These patterns developed both inside 50-nanometer grains and along grain boundaries, creating a global self-organization effect
• Modeling extends the experimental findings to  alloys relevant to practical, real-world applications

What they're saying

"What's remarkable about this discovery is that we've shown these materials can achieve a unique steady state regardless of their initial condition. The material essentially heals itself by continuously reorganizing into the same pattern even after significant disruption." -Assistant Professor Marie Charpagne 

“Another remarkable finding is that nanocrystalline alloys operating in nonequilibrium environment can develop self-organized and dynamically stable patterns across multiple length scales.” - Donald W. Hamer Professor Pascal Bellon 

How it works

1. Under continuous radiation, the alloy forms nanoscale precipitates both inside larger grains and along grain boundaries
2. These precisely sized and spaced particles create a stable, dynamical pattern that resists further damage
3. When a temporary change in irradiation conditions disrupts this pattern, the material automatically reorganizes back to this optimal structure
4. The phenomenon works through a delicate balance of radiation effects, including point defect production, chemical mixing and solute diffusion

The bottom line

The finding challenges conventional wisdom about radiation damage in materials. Rather than simply trying to resist damage, future materials could be designed to use radiation as a tool to create more resilient structures.

Illinois Grainger Engineering Affiliations 

Robert Averback is an Illinois Grainger Engineering professor emeritus in the Department of Materials Science and Engineering. 

Pascal Bellon is an Illinois Grainger Engineering professor in the Department of Materials Science and Engineering and is affiliated with the Materials Research Laboratory. He holds the Donald W. Hamer Professor appointment.

Marie A. Charpagne is an Illinois Grainger Engineering assistant professor in the Department of Materials Science and Engineering and is affiliated with the Department of Mechanical Science and Engineering, the Department of Aerospace Engineering, the Materials Research Laboratory and the Beckman Institute.