Advancements in predicting the composition of metallic glasses will help the Air Force meet the requirements of tomorrow's technologies.

AFRL scientists made significant progress in developing bulk metallic glasses to improve the durability and performance of aerospace components. They also successfully created working scientific models that can predict the composition of new metallic glasses, a capability that helps researchers determine in advance whether a particular glass can be manufactured in bulk form. As a direct result of their effort, researchers recently discovered several new bulk metallic glasses. Their work also led to the successful development of a new technique to illustrate the topology of amorphous (noncrystalline) metal alloys.

This illustration shows 4 candidate atomic clusters with efficient atomic packing for solute atoms with respective coordination numbers of 9, 10, 12, and 13. These clusters illustrate the local atomic structure in many metallic glasses.
These advancements will enable the Air Force (AF) to develop metallic glasses with the exceptional functional properties required to meet the demands of tomorrow's crucial technologies. Thus, these research results facilitate the development of tougher, higher-performance aerospace components that will benefit the AF, commercial aviation, and industry in general.

As materials with exceptional functional properties— magnetic and structural qualities, in particular—metallic glasses have tremendous potential. However, most metallic glasses must be cooled very quickly, at rates faster than approximately 1000°C/sec. Achieving these high cooling rates typically requires that one dimension of the produced material measure <0.5 mm. Only a few bulk metallic glasses exhibit critical cooling rates low enough to produce bulk pieces >1 mm.

Since research in metallic glasses began about 40 years ago, today's researchers had no basis for determining—prior to manufacturing—whether a new alloy could be produced in bulk form. There existed no clear, reliable methodology for predicting new bulk metallic glass compositions. AFRL research conducted over the past 2 years has remedied this limitation by providing useful predictive models based on the number and sizes of atoms.