Metallic Glass

Metallic glass is a metallic material with an amorphous, non-crystalline atomic structure. Most glassy metals are alloys of several metals with high viscosities that prevent them from solidifying into the tightly ordered atomic structure of most metals and crystals.

Metallic Glass Yields Secrets Under Pressure – [ciw.edu]

Tuesday, March 16, 2010
Metallic glasses are emerging as potentially useful materials at the frontier of materials science research. They combine the advantages and avoid many of the problems of normal metals and glasses, two classes of materials with a very wide range of applications. For example, metallic glasses are less brittle than ordinary glasses and more resilient than conventional metals. Metallic glasses also have unique electronic behavior that scientists are just beginning to understand. In a new study, scientists at the Carnegie Institution used high pressure techniques to probe the connection between the density and electronic structure of a cerium-aluminum metallic glass, opening up new possibilities for developing metallic glasses for specific purposes.

Metallic glass: A drop of the hard stuff – [newscientist.com]

Metallic glass sounds like an oxymoron, and in a way it is. It describes a metal alloy with a chaotic structure. While metal atoms normally arrange themselves in ordered arrays, or crystals, the atoms in a metallic glass are a disordered jumble, rather like the atoms in a liquid or a glass. And although strictly speaking a metallic glass isn’t a liquid, because the atoms are fixed in place, one company is already marketing the stuff as “liquid metal”.

It is the unusual structure that makes metallic glass so promising. In crystalline metal alloys, the atoms are ordered within regions called “grains”, and the boundaries between the grains are points of weakness in the material. Metallic glasses, however, have no grain boundaries, so they are much stronger. Hit a crystalline metal with a hammer and it will bend, absorbing some of the energy of the blow by giving way along grain boundaries. But the atoms in an amorphous metal are tightly packed, and easily bounce back to their original shape after a blow (see Diagram). These materials lack bulky crystalline grains, so they can be shaped into features just 10 nanometres across. And their liquid-like structure means they melt at lower temperatures, and can be moulded nearly as easily as plastics.

Glass you can build with: Metallic glass that’s stronger and lasts longer – [physorg.com]

March 24, 2009
Now researchers at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California at Berkeley, working with colleagues at the California Institute of Technology, have solved the fundamental problem of poor fatigue resistance in bulk metallic glasses. The results are metallic glass alloys that are not only stronger than high-strength steel and aluminum alloys but more resistant to fatigue as well.


Under Pressure, Atoms Make Unlikely Alloys
– [ciw.edu]

Washington, D.C., 11 March 2009—Ever since the Bronze Age, humans have experimented with combining different metals to create alloys with properties superior to either metal alone. But not all metals readily form alloys, for some pairs of elements the atoms are too dissimilar.

Now researchers in an international team have discovered that previously impossible alloys can be created by subjecting atoms to high pressure―opening up possibilities for new materials in the future.

Previous studies have shown that at pressures thousand of times larger than atmospheric pressure atoms change their properties and combine under different rules, creating new materials. But the cerium-aluminum alloy produced at the Carnegie Institution’s Geophysical Laboratory breaks new ground in the development of alloys.

SEE ALSO:
Glass Grows Up
Liquid Glass
Quasicrystals

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