Tiny but mighty precipitates toughen a structural alloy

Scientists at the Department of Energy’s Oak Ridge National Laboratory and the University of Tennessee, Knoxville, have found a way to simultaneously increase the strength and ductility of an alloy by introducing tiny precipitates into its matrix and tuning their size and spacing. The precipitates are solids that separate from the metal mixture as the alloy cools. The results, published in the journal Naturewill open new avenues for advancing structural materials.

Ductility is a measure of a material’s ability to undergo permanent deformation without breaking. It determines, among other things, how much a material can elongate before fracturing and whether that fracturing will be graceful or catastrophic. The higher the strength and ductility, the tougher the material.

“A holy grail of structural materials has long been, how do you simultaneously enhance strength and ductility?” said Easo George, principal investigator of the study and Governor’s Chair for Advanced Alloy Theory and Development at ORNL and UT. “Defeating the strength–ductility trade-off will enable a new generation of lightweight, strong, damage-tolerant materials.”