A Faster Way to Sort through BMG Alloys
Posted on: 04/17/2014
Scientists at Yale University have devised a significantly 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.
BMGs are metal alloys 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, as well as in mobile phones, and other consumer electronics.
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. The Yale researchers believe that their 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. The alloy elements are mixed at various controlled ratios, yielding thousands of millimeter size and micron thick samples.
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