Materials scientists working on a collaborative project between the California Institute of Technology and the U.S. Department of Energy’s Lawrence Berkeley National Laboratory have managed to produce an incredible breakthrough: a new type of metallic glass.
What’s even more amazing is the new superglass has a durability and strength beyond any other man-made material. It rids itself of the brittleness of glass while maintaining integrity and strength while being more lightweight.
The metallic glass in use today has brittleness and durability issues. The new material overcomes those problems.
Information about the revolutionary glass is featured in Nature Materials.
One of the authors of the paper describing the new glass, materials scientist Robert O. Ritchie, Ph.D., Sc.D. , and a professor at U.C. Berkeley, told Nature Materials: “It has probably the best combination of strength and toughness that has ever been achieved. It’s not the strongest material ever made, but it’s certainly one of the best with a combination of strength and toughness.”
Ritchie is part of the team that worked on the material at the Lawrence Berkeley National Laboratory.
Glassy materials are notorious for their brittleness and tendency to shear. The shears lead to crack, so most glass alloys are not very useful over the long haul.
The new material overcomes that problem. Unlike the commercial versions of metallic glass used the past few years to make novel sports accessories like baseball bats and golf clubs, the new damage-tolerant material is a palladium micro-alloy that features a much higher “bulk-to-shear” stiffness ratio.
“Because of the high bulk-to-shear modulus ratio of palladium-containing material, the energy needed to form shear bands is much lower than the energy required to turn these shear bands into cracks,” Ritchie said. “The result is that glass undergoes extensive plasticity in response to stress, allowing it to bend rather than crack.”
Strength and toughness usually don’t show up in the same material. If a material is strong, it’s often brittle—and if tough, it’s usually not that strong.
Steel is a good example of something both tough and brittle. Creating glass with the properties of steel has been a dream of materials scientists for almost a century.
The new glass that Ritchie and the other scientists have created is better than steel. That bears repeating: the new glass alloy is tougher and stronger than steel.
Yet it’s still glass.
The applications are limited only by the imagination. Ritchie envisions the future of materials like this used for things as diverse as aircraft, ships and submarines, bridges, even girders that might hold the weight of 150 story super-skyscrapers.
“For a bridge, a ship, a spacecraft, for engine material, you would like to combine strength and toughness,” Ritchie explained. “This does provide a means of doing that in quite frankly the most unlikely of all materials, a glass.”
At present the process needed to create the glass is very expensive and time-consuming. As the years progress though, metallic glass will be showing up in the most unlikely places.
