Scientists use neutrons to discover strengthening behavior in alloys

Oak Ridge National Laboratory researchers have identified a mechanism in a 3D-printed alloy—termed "load shuffling"—that could enable the design of better-performing lightweight materials for vehicles.

One way to improve energy efficiency in vehicles is to make them lighter with aluminum-based materials. Researchers monitored a version of ORNL's ACMZ—aluminum, copper, manganese and zirconium—alloy for deformation that occurs when the material is under persistent mechanical stress at high temperatures.

Using neutron diffraction, researchers studied the material's atomic structure and observed that the overall stress was absorbed by one part of the alloy but transferred to another part during deformation. This back-and-forth shuffling prevents strengthening in some areas.

"Neutrons offer opportunities to study metallurgical phenomena in multiphase structural materials," ORNL's Amit Shyam said. "We've gained unprecedented insight into elevated-temperature material behavior that will allow us to design improved aluminum alloys for extreme conditions."

The research is published in the journal Acta Materialia.