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.
"It has probably the best combination of strength and toughness that has ever been achieved," said Robert O. Ritchie, a materials scientist at Lawrence Berkeley National Laboratory who is one of the authors of a paper describing the new glass. "It's not the strongest material ever made, but it's certainly one of the best with a combination of strength and toughness."
In other words, 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.
