Science

New alloy claimed to have higher strength-to-weight ratio than any other metal

New alloy claimed to have high...
A sample of the high-entropy alloy (Photo: North Carolina State University)
A sample of the high-entropy alloy (Photo: North Carolina State University)
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A sample of the high-entropy alloy (Photo: North Carolina State University)
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A sample of the high-entropy alloy (Photo: North Carolina State University)

When it comes to metal that's being used in the automotive or aerospace industries, the higher its strength-to-weight ratio, the better. With that in mind, researchers from North Carolina State University and Qatar University have developed a new alloy that reportedly has a low density similar to that of aluminum, but that's stronger than titanium.

The material is a type of high-entropy alloy, meaning that it's made up of at least five metals in more or less equal amounts. In this case, those metals are lithium, magnesium, titanium, aluminum and scandium.

"It has a combination of high strength and low density that is, as far as we can tell, unmatched by any other metallic material," said NCSU's Dr. Carl Koch, senior author of a paper on the research. "The strength-to-weight ratio is comparable to some ceramics, but we think it’s tougher – less brittle – than ceramics."

He additionally informed us that while carbon fiber very likely has a higher strength-to-weight ratio than the alloy, it also wouldn't be as tough – in other words, the alloy would be more likely to bend under an amount of stress that would cause the carbon to fracture.

More work still has to be done in the testing of the alloy, along with establishing a practical production method. Koch and his colleagues are also looking into replacing or eliminating the scandium that makes up 20 percent of the material, as it's very expensive.

The research paper was published this week in the journal Materials Research Letters.

Source: North Carolina State University

7 comments
David Mott
Scandium could probably be replaced with scarfium, but then oxygen depletion becomes an issue. IAIA.
Jay Finke
Sounds like this would make a nice engine block, requiring less oil to lubricate ? I hope to see one day a direct inject gas 500 hp V8 engine, with sealed lubrication, that could be picked up with one hand.. how cool would that be.
Eric Pesola
Suggested name for new allow... "Adamantium"
Michael Erdmier
Clicked on the article partly to know the name of the new alloy. I say we just go with Eric's above and call it "Adamantium", lol.
David Clarke
It seems a bit strange to make the alloy with scandium, and then try to find a substitute. It was always expensive. Is expense a consideration?
kalqlate
@David Colton Clarke - "Is expense a consideration?" Perhaps not during experimentation and discovery. However, when considering a place for it in the market, you don't want your wonder alloy priced out of the market when other lower-cost materials might perform the job decently well.
Slowburn
@ David Colton Clarke Because the way that atoms interact is not completely understood after you design an alloy you still have to make physical tests to see if it matches predictions. Spending a fortune to find a substitute and then finding that the original alloy wouldn't form as predicted is embarrassing.