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University
Of Virginia Scientists Discover Amorphous Steel
Material is three times stronger than conventional steel and non-magnetic
July 2, 2004 --
Scientists at the University of Virginia have announced
the discovery of a non-magnetic amorphous material that is three
times stronger
than conventional steel and has superior anti-corrosion properties.
A future variation of the new material, called DARVA-Glass 101,
could be used for making ship hulls, lighter automobiles, tall
buildings, corrosion-resistant coatings, surgical instruments and
recreational equipment. The scientists say commercial use of the
material could be available within three to five years.
The
material, made up of steel alloys that possess a randomized arrangement
of
atoms -- thus “amorphous steel” -- was
discovered by modifying an earlier version of amorphous steel known
as DARVA-Glass 1 reported by the U.Va. researchers at the Fall
2002 meeting of the Materials Research Society. In May of this
year they reported on DARVA-Glass 101 in the Journal of Materials
Research.
“Amorphous
steels can potentially revolutionize the steel industry,” said
Joseph Poon, professor of physics at U.Va. and one of the U.Va.
researchers who discovered the material and is now making alterations
of it for possible
future use in mass production.
The
other U.Va. researchers nclude Gary
Shiflet, professor of materials science and engineering, and
Vijayabarathi Ponnambalam,
materials physicist. Their project
is sponsored by the Defense Advanced Research Projects Agency’s
Structural Amorphous Metals Program.
According
to Shiflet, researchers have been trying for years to make amorphous
steel in sizes
large enough to have practical
use. The
U.Va researchers have succeeded in producing large-size
amorphous steel samples that can be further scaled up. They achieve
this by adding a small dose of a rare earth element or yttrium
to
DARVA-Glass 1. The researchers believe that the large size
rare earth or yttrium
atom causes destabilization of the competing crystal structure
wherein the significant atomic level stress can lead to
the
formation of the amorphous structure. These discoveries
make the U.Va.
researchers optimistic that the material will be economically
available within
the decade.
In
a separate work, a group led by C.T. Liu, a materials scientist
at the Oak Ridge National Laboratory in
Tennessee,
has also
reported on large size amorphous
steel similar to DARVA-Glass 101 in the June issue of Physical Review
Letters, also by modifying the DARVA-Glass 1 discovered
by the U.Va scientists.
Poon
said the amorphous steel is extremely strong, but brittle in
its current state. “We
need to toughen the material more,” he said. “We
can always make it better.”
According
to Shiflet, amorphous steel can be machined as
well as manipulated like a plastic.
The
material is of particular interest to the Navy for making non-magnetic
ship hulls, particularly for submarines, which are
detectable by
the magnetic field
of their hulls. The amorphous steel that the U.Va. team is refining
is non-magnetic, potentially making a ship invisible to magnetism
detectors and mines that
are detonated by magnetic fields. The new material also may be
useful for producing
lighter but harder armor-piercing projectiles. The publicly traded
company
Liquidmetal Technologies owns an exclusive license to the amorphous
steel invented by the
U.Va. scientists.
Other
possible uses include recreational equipment such as tennis racquets,
golf clubs and bicycles as well as electronic
devices.
Poon
can be reached at 434-924-6792 or sjp9x@virginia.edu. Contacts:
Fariss Samarrai, (434) 924-3778 or Charlotte Crystal, (434) 924-6858 |