Researchers from the US Department of Energy's Lawrence Berkeley National Laboratory and the California Institute of Technology have created a new type of metallic glass that may be the world's toughest known material. The new metallic glass is a microalloy featuring palladium, this mix prevents the glass from shattering under stress because it takes less energy to bend than to crack this new material.
Unfortunately, the production of this metallic glass is still too complicated for large-scale production. The researchers' first rod was just 1mm in diameter and only after adding silver to the mix were they able to reach a diameter of 6mm.
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.