Worlds toughest Material

A collaboration between the Department of Energy's Lawrence Berkeley National Laboratory and the California Institute of Technology has developed a new form of metallic glass that is stronger and tougher than steel and may in fact be the world's toughest known material.

Robert Ritchie, one of the team's lead researchers comments: "These results mark the first use of a new strategy for metallic glass fabrication and we believe we can use it to make glass that will be even stronger and more tough."
Meaning the best may be yet to come.
In the world of material sciences, "strength" refers to a material's ability to withstand applied stress without failure (i.e. breaking, splintering, cracking). Whereas "toughness" refers to how much energy a material can absorb before failing—this is important for materials that are designed to withstand impact.
Glassy materials are inherently strong, but also very brittle (as in, not tough). Small shears can spread as cracks, resulting in material failure. However, the crystalline structure of metals can provide microstructual obstacles that can stop larger cracks from forming. It's difficult to shatter a sheet of metal with a hammer, but it's quite a different story for a sheet of glass.
The new metallic glass is a microalloy featuring palladium, a metal with a high "bulk-to-shear" stiffness that can counteract the brittleness of glassy materials. The palladium allows glassy materials to undergo extensive plasticity in response to stress—it takes less energy to bend than to crack.

"The addition of the palladium provides our amorphous material with an unusual capacity for extensive plastic shielding ahead of an opening crack," explains Ritchie. "This promotes a fracture toughness comparable to those of the toughest materials known. The rare combination of toughness and strength, or damage tolerance, extends beyond the benchmark ranges established by the toughest and strongest materials known."

But we shouldn't get enamored with fantasies of cars, buildings, and machines made from unbreakable materials quite yet. The production of this new metallic glass is still too intricate for the industrial scale. The original incarnation could only create rods that checked in at the 1 mm diameter mark. Only after the team added silver into the mix were the able to up the diameter to whopping 6 mm.

Still, this is a huge step towards the materials that will build a strong new future.