By cooling slowly and then quickly, the scientists allowed tiny Christmas tree-like crystalline structures to grow through the metal. Rapidly cooling the rest of the metal maintains the glassy atomic structure. The crystalline structures stop any cracks from moving more than two to five microns in length. The glass gives the material its strength, while the Christmas tree-structures give it toughness. In subsequent stress tests the 1 to 10-centimeter pieces of glass were dramatically tougher than any previous metallic glass, a full order of magnitude more resistant to breaking and stronger than steel. "This is a major accomplishment," said William Nix of Stanford University. "One big advantage [of the new glass] is that it can be cast right to shape. Just pour it into a mold, let it freeze, and you have properties that are comparable to high-strength steel right from the get-go." Since the alloy is titanium and zirconium instead of steel, it weighs significantly less than steel. It also melts at much lower temperatures than steel, making it easier and faster to produce. "We could make an airplane out of metallic glass," said Launey. "But the problem is always the same. Processing these materials is kind of expensive." Related Links: |
advertisement
Put Discovery News on Your Site!
|
-
our sites
-
video
mobile
-
shop
-
stay connected
-
corporate
