Now, glass that is stronger than steel

Scientists have developed a new type of glass that is stronger than steel, paving way for 'unbreakable' medical implants, mobile phones and other electronics.
Scientists at Yale University devised a dramatically faster way of identifying and characterising complex alloys known as bulk metallic glasses (BMGs), a versatile type of pliable glass that is 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.

"This should dramatically hasten the discovery of BMGs and new uses for them," said Schroers.

BMGs are metal alloys composed typically of three or more elements, such as magnesium, copper, and yttrium.
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, as well as in mobile phones, and other consumer electronics, said Schroers.

Schroers said there are an estimated 20 million possible BMG alloys. About 120,000 metallic glasses have been produced and characterised to date.
Using standard methods, it would take about 4,000 years to process all possible combinations, Schroers said. 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 millimetre 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.
The study was published in the journal Nature Materials.