Materials

Novel alloy boasts unparalleled elasticity at room temperature

Scientists have developed a novel alloy with a high degree of elasticity
Sheng Xu et al.
Scientists have developed a novel alloy with a high degree of elasticity
Sheng Xu et al.

While most metals feature some degree of elasticity, some respond better than others to being bent out of shape. Scientists experimenting with the makeup of these materials have developed a novel, copper-based alloy they say would be simple to produce at scale, and boasts unparalleled elasticity at room temperature.

For a metal to have high elasticity, it needs to be easily stretched and deformed, measured by what’s called Young’s modulus, while still being strong enough to return to its original form. Integrating these properties into metals and alloys is a tricky balancing act, with one often compromising the others, but through careful engineering materials can be produced to meet specific requirements for everyday applications.

One example is stainless steel, which has a high tensile strength and is resistant to a wide range of temperatures and corrosion, and is therefore used in everything from cookware, to operating theaters, to outer space. You mightn’t know it by looking at your saucepan, but stainless steel even has a tiny amount of give in it, with an elastic strain value of <0.2%.

This goes for many metals and alloys, which in their bulk form exhibit an elastic strain value of under 1%, (though on micro and macro scales this figure sits at about 10%). Engineers at Tohoku University have put forward a new copper-based alloy that takes these type of bulk metals into flexible new terrain.

The team’s copper-based single crystalline alloy in bulk form is remarkably strong and features an exceptionally high tensile elastic strain of 4.3% at room temperature, which is said to be unmatched among such materials. It does so in a way that defies what’s known as Hooke’s law, which says that the elasticity of a material is proportional to the stress applied, by being highly elastic even when subjected to only small amounts of stress.

This type of material could be put to use in everything from more flexible sporting goods to advanced medical implants that better conform to the human body. The scientists are now exploring these possibilities while further studying the performance of the alloy to ascertain its functional fatigue after such large deformations. Promisingly, they say the cyclic heat treatment used to prepare the alloy’s single crystals is a simple process that lends itself well to mass production.

"Our bulk alloy can be used as spring materials with high recoverability, and they could also be applied to devices that employ strain-mediated sensors, such as stretchable electronics" said Sheng Xu, who led the research. "The new alloy's low Young's modulus resembles human bones and therefore has the potential for use in medical applications."

The research was published in the journal Nature

Source: Tohoku University

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6 comments
vince
Wouldn't it be cool if they could make car bodies and frames from a metal that could endure a 30 mph crash and after the crash rebound back to it's original form? Man that would put 50% of all body shop's out of business !
Noah Tall
WOW! We could make Robots out of the stuff, human bones like, maybe muscle too.
The material made with a memory, can heat up a few degrees, melt, pour under a door, reconstitute, and the come get ya,
like in Robocop.
Neat-O!
Bob Stuart
First off, a lot of stainless steel lacks carbon, and is often half the strength of aluminum alloy. Second, Young's Modulus is usually not much affected by alloying, so this may be big news that way. An elastic range over 4% is also very big news in any metal. However, instead of seeing the actual numbers, including tensile strength, I just got a word salad that leaves me wondering what has been accomplished.
Mark T.
"Bulk single crystals of Cu69Al17Mn14 (in atomic percent) with an L21-type ordered BCC structure (β phase) were prepared in the form of sheets of ~60 mm long by abnormal grain growth induced by cyclic heat treatment." - For those who like to know what they are looking at.
Ancliff
A video would have been a real plus
ReservoirPup
@Bob Stuart: yep, stainless steel is a very diverse bunch. They can be only stainless in the name, e.g. AISI 430. AISI 304 is much closer to what the author meens😉