Islands without structure inside metal alloys could lead to more resistant materials

An international team of researchers has produced islands of amorphous and non-crystalline material within a class of new metal alloys called high entropy alloys.

This discovery opens the door to applications in all fields, from landing gears to pipelines, including automobiles. New materials could make them lighter, safer and more energy efficient.

The team, which includes researchers from the University of California at San Diego and Berkeley, as well as Carnegie Mellon University and the University of Oxford, details their findings in the Jan. 29 issue of Scientific advances.

“These have brilliant potential for increased strength and toughness, because metallic glasses (amorphous metals) have a much higher strength than crystalline metals and alloys,” said Marc Meyers, professor in the Department of Mechanical Engineering and UC Aerospace. San Diego, and the corresponding author of the article.

Using transmission electron microscopy, which can identify the arrangement of atoms, the researchers concluded that this amorphization is triggered by extreme deformation at high speeds. This is a new strain mechanism that can further increase the strength and toughness of these high entropy alloys.

The research is based on the founding work of Brian Cantor at the University of Oxford and Jien-Wei Yeh at National Tsing Hua University in Taiwan. In 2004, the two researchers led teams that reported the discovery of high entropy alloys. This sparked a worldwide search for new materials of the same class, motivated by many potential applications in the transport, energy and defense sectors.

“New developments and significant discoveries in metal alloys are quite rare,” Meyers said.