Earlier this year, a story about an ultra-strong, flexible glass called Gorilla glass hit the web. But now….
A glass that is stronger and tougher than steel has been developed in the lab in a collaboration between the Lawrence Berkeley National Laboratory and the California Institute of Technology (Cal-Tech), funded by the Department of Energy Office of Science.
This glass can bend, if subjected to stress, rather than shatter. The new kind of strong glass material is a microalloy with palladium, a metal with a high “bulk-to-shear” stiffness ratio that counteracts the intrinsic brittleness of glassy materials.
The initial samples of the new metallic glass were microalloys of palladium with phosphorous, silicon and germanium that yielded glass rods approximately one millimeter in diameter. Adding a fifth metal, silver, to the mix enabled the Cal Tech researchers to expand the thickness of the glass rods to six millimeters.
“The rule of thumb is that to make a metallic glass we need to have at least five elements so that when we quench the material, it doesn’t know what crystal structure to form and defaults to amorphous,” says Robert Richie, the lead author of “A Damage-Tolerant Glass” just published the research in the journal Nature Materials.
Ritchie holds joint appointments with Berkeley Lab’s Materials Sciences Division and the University of California (UC) Berkeley’s Materials Science and Engineering Department.
Co-authors were Cal-Tech’s William Johnson; one of the pioneers in the field of metallic glass fabrication, and Marios Demetriou, who actually made the new glass with funding from the National Science Foundation, and Maximilien Launey, Glenn Garrett, Joseph Schramm and Douglas Hofmann who joined Ritchie and Johnson in characterization and testing at UC Berkeley, funded by the DOE.
In earlier version, the Berkeley-Cal Tech collaboration stopped microscopic cracks from becoming “shattered” glass fragments, by building micro-structural barriers with the metals.
In this new phase, the group takes it a step further. By making the glass able to bend, it can’t even develop a crack to lead it to eventually shatter.
In the process, they have created a new kind of a glass that is stronger and tougher than any material known.
Potentially, a solar roof protected within a glass that’s stronger than steel would need a great deal less roofing infrastructure to hold it up, reducing both solar (and roofing) prices. The research was funded by the Department of Energy and the National Science Foundation.