World’s Toughest Material Has Bizarre Property, Scientists Find

Read on to learn more about this wonder substance that rivals Vibranium.

hard stuff

The hardest material on earth is a metallic alloy of chromium, cobalt and nickel. It’s 100 times stronger than graphene, a supermaterial that’s 200 times stronger than steel and 1,000 times lighter than paper.

While the researchers were previously aware that the material is tough, they were surprised to learn that it becomes even tougher when exposed to extremely cold temperatures. Other materials, including graphene, become increasingly brittle as temperatures drop, while this high entropy alloy (HEA) is extremely fracture resistant.

Robert Ritchie, a professor at the University of California Berkeley, senior faculty scientist at Lawrence Berkeley National Laboratory and co-author of the study, told Live Science, “The toughness of aluminum alloys used in aircraft is 35 megapascals per meter. This material has a toughness of 450 to 500 megapascals per meter… those are amazing numbers.”

MSE professors Ritchie, Minor, Asta and colleagues at Oak Ridge National Laboratory have created the world’s toughest material. The work focuses on an alloy of chromium, cobalt and nickel and shows a way to produce a ductile and very strong material pic.twitter.com/kllfvzfypO

— Berkeley MSE (@BerkeleyMSE) December 15, 2022

Applications in the real world

So what applications would be ideal for this tough alloy? It could be integrated into space infrastructure or used to build shatterproof containers for clean energy projects. A good application can be, for example, hydrogen storage tanks for hydrogen-powered vehicles. The problem is that nickel and cobalt are extremely expensive, so Ritchie says the alloy won’t be used outside of a lab anytime soon.

HEAs are made up of an equal mixture of elements, while other alloys are made up of one predominant element with other mixed elements. The chromium-cobalt-nickel alloy bends under pressure, and this malleability prevents it from breaking. It does not deform or break like other materials under strong pressure. In fact, it gets even stronger in colder temperatures.

Scientists first tested the alloy by exposing it to liquid nitrogen at temperatures around minus 321 degrees Fahrenheit. Instead of weakening, the alloy got stronger. The researchers then exposed the alloy to liquid helium, which can reach temperatures as low as minus 424 degrees Fahrenheit.

scale up

Compared to graphene, HEA was exponentially harder. According to physicist Dong Liu, a study co-author from Bristol University, graphene is strong but lacks damage tolerance. “It’s very brittle and it breaks just like a mug you throw on the floor and it shatters into pieces,” he told Live Science.

And while graphene may be tough, it only maintains its strength in the “nanometer” range while the chromium-cobalt-nickel alloy has been tested in cigarette pack-sized portions. This makes it a more practical material for common items.

Further research on the HEA needs to be done to determine its usability under real-world conditions. Ritchie, on the other hand, is keen on developing new alloys that are similarly tough and use a variety of different elements from the periodic table, creating “millions of new alloys.”

By Noelle Talmon, contributor to Ripleys.com