A team of scientists at the University of California, Irvine has made a breakthrough that could change how we understand the way metals bend and deform under pressure.
For over 70 years, scientists believed that tiny lines called “slip bands”—which appear when metals are compressed—formed in a specific way described by a model from the 1950s.
But this new study, published in Nature Communications, shows that the old explanation might be incomplete.
Slip bands are important because they show how metals react to stress, which affects how strong and reliable materials are.
This matters for everything from jet engines to spacecraft to nuclear reactors—places where materials face extreme conditions and need to be tough.
The classic theory, created by Charles Frank and Thornton Read, said that slip bands form when defects in a material, called dislocations, multiply from the same starting point over time.
But the UC Irvine researchers, led by Associate Professor Penghui Cao, discovered something different.
By zooming in to the atomic level while compressing a very strong alloy made of chromium, cobalt, and nickel, they saw a new type of slip band form.
These “extended slip bands” appeared not because of one active dislocation source, but because some sources stopped working and new ones were activated dynamically as the metal was stressed.
The team used powerful tools—including a type of microscope that can see atoms and advanced computer simulations—to study how the alloy reacted during stress.
They found that there are two types of slip bands: confined slip bands, which are thin and have few defects, and extended slip bands, which have more internal flaws and spread across a larger area. This new behavior was not predicted by older theories.
Cao explained that the exact process of how slip bands form at such a small scale has remained unclear since the 1950s. Now, by watching what happens at the atomic level, his team has provided a clearer picture of how advanced materials behave when they’re under pressure.
These findings are especially important because new materials like the chromium-cobalt-nickel alloy—considered one of the toughest known—are being used more often in extreme environments.
Understanding how they react to stress helps engineers design safer and more reliable parts for high-stakes industries like aerospace and energy.
According to Cao, this research lays the groundwork for creating next-generation materials that are not only strong but also behave in predictable ways.
That means better performance, fewer surprises, and safer designs in everything from space travel to power plants.
Source: UC Irvine.
