In probing mysteries of glass, researchers find a key to toughness

Glass doesn't have to be brittle. In a paper published online Feb. 26 , a Yale University team and collaborators propose a way of predicting whether a given glass will be brittle or ductile - a desirable property typically associated with metals like steel or aluminum - and assert that any glass could have either quality. Ductility refers to a material's plasticity, or its ability to change shape without breaking. "Most of us think of glasses as brittle, but our finding shows that any glass can be made ductile or brittle," said Jan Schroers, a professor of mechanical engineering and materials science at Yale, who led the research with Golden Kumar, a professor at Texas Tech University. "We identified a special temperature that tells you whether you form a ductile or brittle glass." The key to forming a ductile glass, they said, is cooling it fast. Exactly how fast depends on the nature of the specific glass.