Glasses strong as steel: A fast way to find the best

Scientists at Yale University have devised a dramatically faster way of identifying and characterizing complex alloys known as bulk metallic glasses (BMGs), a versatile type of pliable glass that's stronger than steel.

Using traditional methods, it usually takes a full day to identify a single metal alloy appropriate for making BMGs. The new method allows researchers to screen about 3,000 alloys per day and simultaneously ascertain certain properties, such as melting temperature and malleability.

"Instead of fishing with a single hook, we're throwing a big net," said Jan Schroers, senior author of the research, which was published online April 13 in the journal Nature Materials. "This should dramatically hasten the discovery of BMGs and new uses for them."

BMGs are composed typically of three or more elements, such as magnesium, copper, and yttrium (Mg-Cu-Y). Certain combinations of elements, when heated and cooled to specific temperatures at specific rates, result in materials with unusual plasticity and strength. They can be used for producing hard, durable, and seamless complex shapes that no other metal processing method can.

Already used in watch components, golf clubs, and other sporting goods, BMGs also have likely applications in biomedical technology, such as implants and stents, mobile phones, and other consumer electronics, said Schroers, who is professor of mechanical engineering and materials science at the Yale School of Engineering & Applied Science.

He said there are an estimated 20 million possible BMG alloys. About 120,000 metallic glasses have been produced and characterized to date.

Using standard methods, it would take about 4,000 years to process all possible combinations, Schroers has calculated. The new method could reduce the time to about four years.

The technique combines a process called parallel blow forming with combinatorial sputtering. Blow forming generates bubble gum-like bubbles from the alloys and indicates their pliability. Co-sputtering is used for fabricating thousands of alloys simultaneously; alloy elements are mixed at various controlled ratios, yielding thousands of millimeter size and micron thick samples.

"Instead of blowing one bubble on one material, we blow-form 3,000 bubbles on 3,000 different materials," Schroers said.

Since 2010, he and his research team have tested about 50,000 alloys using the new method and identified three specific new BMG . They are focused on 10 alloy families.

Ideal BMGs offer plasticity during the manufacturing process, durability, and biocompatibility, along with affordability, Schroers said. Some constituent elements can be costly.

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More information: "Combinatorial development of bulk metallic glasses" DOI: 10.1038/nmat3939
Journal information: Nature Materials

Provided by Yale University
Citation: Glasses strong as steel: A fast way to find the best (2014, April 13) retrieved 20 October 2019 from
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Apr 13, 2014
Calling these metals "glasses" is about as misleading - to the general public - as you can get.
SHAME on you Yale University PR department!!!

Apr 13, 2014
Why can't they call it glassy metals/alloys? English is not that hard. putting the "metallic" before the "glasses" make it an adjective. Like a "sour apple". It means the apple is sour, not sourness is the apple as is the equivalency of "metallic glass".

Apr 13, 2014
These boffins must be really desperate and longing for transparent aluminum. Why else they keep peddling glasses with metallic characteristics, according to grammatical rules? Science is supposed to be precise. Most metals are known to be crystalline, not amorphous like ordinary glass, so why not call these special ones amorphous metals/alloys? Pathetic PR.

Apr 13, 2014
Good comments, all...:-)
Skepticus' remark let's me know that the Star Trek phenomenon is not yet dead...:-) Long live Scotty!

Apr 13, 2014
Transparent aluminum already exists. It's called sapphire. It should be possible to make this in most any size in the near future. There are pics of 1ft dia windows somewhere on this site.

Apr 14, 2014
Can't we model these alloys mathematically? Via computer simulation seems like a much more efficient way to evaluate them.

Apr 14, 2014
Calling these metals "glasses" is about as misleading - to the general public - as you can get.
SHAME on you Yale University PR department!!!

Why shame on them? They don't get to decide. Physicists and chemists distinguish glass from crystal by its structure, not by transparency, which is the colloquial criterion. Plexiglass is not a glass to physicists and chemists either, but polymer. Aren't scientists supposed to care about about underlying structure? Do you think everything that is transparent and solid should be called glass? Those metallic glasses get their name from sharing a structure with window glass. The alternative to having a technical and a colloquial meaning for some words is to invent new words for each new idea, even if you don't know yet whether you will need a new word. That leads to accusations of needless jargon.

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