鈥淕LASSY鈥� steel more than twice as hard and strong as the best quality conventional steel has been created. It could one day be used in everything from reinforced concrete to submarine hulls.
Metals ordinarily have a crystalline structure, with their atoms arranged in neat, orderly rows, but glassy materials are irregular and disordered. Glassy metals are stronger because the chaotic packing of the atoms prevents them slipping past each other. Metallurgists have already made some glassy metals, including a zirconium alloy that is used in tennis rackets and mobile phone casings. But glassy steel could only be produced in granule form.
Now a team led by Zhao Ping Lu at Oak Ridge National Laboratory in Tennessee has found a way to make glassy steel in bulk by adding small quantities of yttrium atoms to an iron alloy. It follows similar, pioneering work by Joseph Poon and his colleagues at the University of Virginia in Charlottesville. The yttrium atoms are larger than iron atoms, so the researchers believe they disrupt the crystalline structure. They have made rods more than a centimetre in diameter, and believe that the glassy steel could be used to create large structures using commercial melting and casting techniques (Physical Review Letters, vol 92, p 245503).
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