Metal or glass? Both

"Metallic glass" sounds like an oxymoron, but it's Todd Hufnagel's goal. Hufnagel, a researcher at Johns Hopkins University, hopes to create a metallic glass in bulk form with superior strength, elasticity, and magnetic properties that will not crystallize at higher temperatures. A glass is any material that can be cooled from a liquid to a solid without crystallizing. Most metals crystallize as they cool, arranging their atoms into a highly regular spatial pattern called a lattice. If crystallization does not occur, and the atoms settle into a nearly random arrangement, the final form will be a metallic glass. Hufnagel and associates are researching the deformation of glass alloys at high rates; and the phase transformation or crystallization window between liquid and solid states, when the material is soft enough to be molded; as well as new combinations of alloys. "Metallic glass is highly elastic, bending 2 to 3% before it permanently changes shape," Hufnagel says. This makes it a useful material for springs. The first commercial application to date is golf club heads. Mountain bike manufacturers are calling about the possibility of using the material as a shock absorber. Because metallic glass would not shrink, yet is extremely flexible, it may be ideal for injection molding, Hufnagel adds. Other applications: engine parts, electric transformers, and military applications, such as armor-piercing projectiles. FAX: (410) 516-5251.