Shape-Memory Alloys
New Body Materials Are Fender Unbenders
Nitinol. Remember the name.
Someday you'll be swearing by it, while body shops are swearing at it.
Nitinol is a nickel-titanium alloy used to produce stents to keep veins and
arteries open. General Motors researchers are working with it, as well as
polymers, to create what they call shape-memory materials.
To illustrate, if you could apply shape-memory materials to humans, husband and
wife would slip into the same outfits for their 50th anniversary that they wore
to their wedding - with nary an alteration to the outfit or the spouses.
Of course, auto engineers are devoted to coming up with more practical, yet
equally far out, applications.
Consider, for example, that Dad gets a dent in the car door that he doesn't want
Mom to know about - or vice versa. Or, son or daughter gets a dent in the door
they don't want Dad or Mom to know about.
Simple, said GM advance technology spokesman Dave Roman. "You grab a hair dryer,
run it over the dent, the dent disappears, and the door goes back to its
original shape."
"The properties in shape-memory alloys (metals) and polymers (plastics) have the
potential to be game changers, eventually leading to vehicles that can self-heal
in the event of damage or be designed to change color or appearance," said Alan Taub, executive director of research and development for GM.
"We'd probably do it with alloys first before polymers and probably on bumpers
first before body panels, but there is nothing in physics that rules it out or
stops it," Taub said.
Heat, stress, magnetic field or electrical voltage is all it takes to change
shape-memory materials.
Imagine body shops where the workers wield hair dryers rather than hammers or
mallets.
Fixing body panels would be an extreme use of the materials, but it's possible
and interesting to think about, Taub said.
He's hoping to offer some more practical applications in 2010. One example is
the air dam below the front bumper that adds to a car's sporty looks - and gets
scraped every time you pull up your steep driveway. With memory material, an
electrical charge applied by a button or fob when approaching the driveway could
change the dam's shape, raising it to prevent contact with the concrete apron.
- Jim
Mateja,
Chicago Tribune, Newsday, Sunday, May 13, 2007
This page was last updated on
05/14/07
.
