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It has long been thought that plastic and steel
were the best materials to use in building large products. These new "shapeless
alloys" combine the strength of steel with the molding capability of
plastic.
Dr. Bill Johnson of Caltech, Pasadena, Calif., has
studied metals with liquid atomic structures for over 30 years. He
eventually teamed up with Dr. Atakan Peker of Liquidmetal
Technologies, Lake Forest, Calif. Peker further helped Johnson develop
the idea of creating thick liquid metals that form glass without the
need for rapid cooling.
Johnson began working in the field in the early
1980s with colleagues at NASA's Jet Propulsion Laboratory. NASA and
Liquidmetal Technologies cooperated on research using the microgravity
conditions available flying on the space shuttle. Extensive
experiments on liquid metals were conducted onboard the International
Microgravity Laboratory flight in 1994 and again in 1997 on the
Microgravity Science Laboratory mission. The work was sponsored by
NASA, Caltech and the U.S. Department of Energy to create new
materials for aerospace.
Johnson has continued this research on the ground
using electrostatic levitation and laser heating. In this process
small spheres are held up in a vacuum and melted by a laser beam. NASA
sponsors two high-vacuum electrostatic levitator facilities for this
research at NASA Marshall Space Flight Center, Huntsville, Ala., and
at Caltech.
Johnson and Peker were able to create a new form of
mixed metals that went from a liquid to a solid at room temperature.
The liquid included a mix of elements: zirconium, titanium, nickel,
copper, beryllium.
Instead of having to quickly cool a liquid metal to
become solid, it cooled and hardened itself at room temperature to
avoid crystallization and become a glass. They named this liquid metal
"Vitreloy." This metal showed massive strength: a one inch wide bar
could lift 300,000 pounds, compared to a titanium bar of the same size
that could only lift 175,000 pounds. Although this material had super
strength, it lacked the attributes that make metals tough. Vitreloy,
was more robust than window pane glass, but still cracked.
The successful method used to toughen Vitreloy and
create Liquidmetal is the same method used to process plastics. In
2000, Johnson and graduate student Paul Kim improved Vitreloy's
toughness while giving it the flexibility to allow it to be made into
many different shapes. Now, the new line of Liquidmetal alloys is on
the rise.
It has been proven that Liquidmetal can handle lots
of stress without losing its shape and is three times more elastic
than other alloys. To test these characteristics, an experiment was
set up. In the experiment, three marble-sized balls made of steel were
dropped from the same height into their own glass tubes. Each tube had
a different type of metal plate at the bottom: steel, titanium,
Liquidmetal. Once each ball was dropped they were left to bounce. The
balls hitting the steel and titanium plates bounced for 20 to 25
seconds. The ball hitting the Liquidmetal plate bounced for 1 minute
and 21 seconds. During the experiment, this was the only ball that
bounced outside its tube.
Liquidmetal Technologies Inc. has an exclusive
license for this product and is finding more uses for it. Plates for
golf equipment were one of the early products in 1996. Now it is being
considered by the U.S. Department of Defense as an armor and
anti-armor material.
HEAD Racquet Sports showed its interest in the
material in 2003 and used it for a new tennis racquet line that
ultimately became the world's top-selling new technology racquet that
same year. Now the Liquidmetal alloy is finding its way into any
number of consumer goods, including, cell phone cases and parts, a
Rawlings baseball bat, HEAD skis and more. The technology is also
being considered for several upcoming aerospace applications. |
