Found! Superhero of metals

New York, July 07: It could be the new superhero of metals. More than twice as strong as titanium and steel, it doesn’t rust and it can be cast like plastic and honed to an edge as sharp as glass.
And like any superhero, it has a weakness: if you heat it too much, it loses its strength. The alloy, discovered by California Institute of Technology, is called Liquidmetal, has already been used in golf clubs. And it may soon show up in cellphone casings, baseball bats and scalpels. Liquidmetal Technologies, the Lake Forest, California company that is trying to commercialise the alloy, is not shy about calling it revolutionary.

“It combines uniquely a material with exceptional properties and the ability to process the material to exceptional shapes,” says Dr Michael Ashby, an advisor to the company.

Liquidmetal’s surprising properties come of a structure different from ordinary metals. When a conventional metal cools, it forms grains, each a small crystal where the atoms are oriented in a grid. The boundaries between these grains are a metal’s weak points it’s where cracks can form and rust starts, for instance.

Scientists discovered in 1959 that if some alloys are cooled very quickly the atoms don’t have time to form crystals. Instead, they remain jumbled, as in a liquid or in glass.

However, the only way to cool the molten metal fast enough was to make it in thin strips or as a sprayed coating. The strips couldn’t be joined, because they were hard to forge, and heat allowed the atoms to crystallize again.

Because of their unique magnetic properties, the strips still found use in the anti-theft tags used by retail stores and in electrical transformers.

In 1992, Dr William Johnson and Dr Atakan Pekers at the Caltech discovered a way around the cooling problem. They made an alloy of elements that fit very poorly together: titanium, copper, nickel, zirconium and beryllium. These elements’ atoms are of different sizes so they don’t readily form crystals, even when cooled slowly. Pieces up to an inch thick could now be made. Bureau Report