Tough Metallic Glass

Metallic glasses were first demonstrated fifty years ago when a team from Caltech produced a paper on gold silicon alloys. Metallic glass is formed when metal atoms cool and solidify without forming a crystal structure. This makes them lightweight and elastic compared to conventional metallic structures. New versions of metallic glass containing palladium and silver show surprising combinations of strength and toughness.

Glasses tougher than steel – [blog.joerg.heber.name]

Glasses are very useful structural materials, because they are strong. You can stand on a glass table without it breaking. But once you put too much stress on a glass it breaks. Steels on the other hand are much tougher — which means that they show a much stronger resistance to fracture: rather than suddenly breaking under stress, steels tend to deform first. This toughness of steel is one of the obvious reasons why steel skeletons instead of glasses are used for the construction of large buildings.

This conception of glasses not being very tough is now made history by Marios Demetriou and colleagues from the California Institute of Technology and The University of California, Berkeley. They have discovered a glass that is not only strong, but also tough as steel. It is a metallic glass, which means that it dominantly consists of metal atoms. Like other metallic glasses it isn’t transparent, but looks like a normal metal — except that unlike crystalline metals its atomic structure is more or less random. The damage tolerance of this metallic glass, its combination of strength and toughness, is higher than any known material. ”It has been usual to regard metallic glasses as damage sensitive, but over recent years it has become increasingly recognised that they can be tough. This new paper marks a further decisive shift in showing that metallic glasses can be very tough indeed,” says Lindsay Greer from Cambridge University, who studies the properties of metallic glasses.

50 years of metallic glasses – [blog.joerg.heber.name]

New Glass Tops Steel in Strength and Toughness

Glass stronger and tougher than steel? A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of any known material, has been developed and tested by a collaboration of researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab)and the California Institute of Technology. What’s more, even better versions of this new glass may be on the way.

A damage-tolerant glass – [nature.com]

Here, a bulk glassy palladium alloy is introduced, demonstrating an unusual capacity for shielding an opening crack accommodated by an extensive shear-band sliding process, which promotes a fracture toughness comparable to those of the toughest materials known. This result demonstrates that the combination of toughness and strength (that is, damage tolerance) accessible to amorphous materials extends beyond the benchmark ranges established by the toughest and strongest materials known, thereby pushing the envelope of damage tolerance accessible to a structural metal.

SEE ALSO:
Metallic Glass
Glass Grows Up
Liquid Glass
Quasicrystals

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