Metallic Glass - tougher than nails :o)

Materials scientists in California have made a special metallic glass with a strength and toughness greater than any known material, using a recipe that could yield a new method for materials fabrication.

The glass, a microalloy made of palladium, has a chemical structure that counteracts the inherent brittleness of glass but maintains its strength. It’s not very dense and it is more lightweight than steel, with comparable heft to an aluminum or titanium alloy.

Some tougher materials exist, but they are less strong; there are stronger materials, but they’re not as tough. To grasp this, you have to define the the difference between strength and toughness. Strength refers to how much force a material can take before it deforms. Toughness explains the energy required to fracture or break something; it describes an object’s ability to absorb energy. Most of the time, these qualities are mutually exclusive. “The holy grail is to get both those properties at the same time,” Ritchie said.

Think of a ceramic mug — it’s pretty strong, maintaining its shape while handling hot and cold temperatures with ease. But it’s not very tough — there’s no give, no bendy quality to stop it from shattering when it falls to the floor. On the other hand, a rubber band is tough, stretching and contorting to wrap itself around your newspaper, your carton of eggs and a myriad other objects. But it’s weak, and it doesn’t take much energy for it to deform and break, snapping back on you with a painful recoil.

Ideal structural materials are both strong and tough; steel is a good example. The new glass has a far better combination of strength and toughness than any steel.

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