Morphing Metals 121
aarondubrow writes "Imagine a metal that 'remembers' its original, cold-forged shape, and can return to that shape when exposed to heat or a magnetic pulse. Like magic out of a Harry Potter novel, such a metal could contract on command, or swing back and forth like a pendulum. Believe it or not, such metals already exist. First discovered in 1931, they belong to a class of materials called 'shape memory alloys (SMA),' whose unique atomic make-up allows them to return to their initial form, or alternate between forms through a phase change."
News? (Score:5, Informative)
SMAs have been well known about for decades, well written about for decades, just what is the point if this article?!
Re:News? (Score:5, Informative)
SMAs have been well known about for decades, well written about for decades, just what is the point if this article?!
I remember reading this in Popular Science (from Jan 1988):
http://books.google.com/books?id=dQEAAAAAMBAJ&pg=PA78&ots=kS_1AvijAF [google.com]
Anyone read TFA? (Score:5, Informative)
"These shape memory materials have many applications," said Raymundo Arroyave, assistant professor of mechanical engineering and materials science at Texas A&M. "Despite being heavily studied for the past twenty to thirty years, most of these materials are limited to work at relatively low temperatures."
In other words, yes - the materials have existed for ages and people know that (anyone ever worn memory-flex glasses, for instance?), but there is now work underway to make the substances more useful in more difficult conditions - TFA mentions aerospace and automotive.
Cheers,
Ian
From TFA (Score:5, Informative)
“These shape memory materials have many applications,” said Raymundo Arroyave, assistant professor of mechanical engineering and materials science at Texas A&M. “Despite being heavily studied for the past twenty to thirty years, most of these materials are limited to work at relatively low temperatures.” “This new class of high temperature shape memory alloys can be used in sensing and actuation at temperatures upwards of 200 Celsius, which is very important for the aerospace and the automotive industries,” Arroyave said.
IOW what's new (or rather isn't actually yet) is "it works at higher temperatures". And that they are trying to find the new materials by simulating them with a supercomputer. Or so they hope, because "Computational materials science has a reputation for overselling and underperforming, according to Arroyave, but by all measures, the field is maturing by leaps and bounds."
Re:News? (Score:3, Informative)
You used to be able to buy glasses with frames made from this, especially for kids - the idea being you could sit on them, scrunch them up in a bag and they'd just straighten out with body heat, when you put them on. Obviously you got scratch resist lenses too.
They seem to do them for adults now too http://www.framesdirect.com/flexon/ [framesdirect.com]
Mark
Wow. (Score:3, Informative)
You mean like those bendable glasses (spectacles) are made of? The ones you can sit on and not break. The ones that have been around for long enough to be known by the layman.
Re:Yes and? (Score:5, Informative)
Are you kidding me? I use Nitinol [wikipedia.org] (the main shape memory alloy) every time I put on my glasses. Many shape memory alloys exhibit a behavior other than the heat-activated shape memory effect: superelasticity [wikipedia.org]. That is what allows me to bend my frames [youtube.com] in all kinds of weird ways without having the metal permanently deform.
Re:Yes and? (Score:4, Informative)
Nitinol is also used many permanent implantable medical devices such as stents http://www.euroflex-gmbh.de/pdfs/medical.pdf [euroflex-gmbh.de] [PDF] and having developed a few devices with Nitinol, it is simply amazing to see it work.
Re:News? (Score:1, Informative)
After reading TFA, it said they discovered the fundamentals of SMAs are different than previously believed. Supercomputer simulations are being used to determine what other atomic structures can have multiple modes with different equalibriums. They propose they can discover more principles of SMAs, and it will lead to new ones being developed (at least in simulation).
Re:News? (Score:3, Informative)
Actually if you read the link. I know what am I thinking read the link on slashdot.
This is about creating high temp SMAs and using super computers to model them instead of melting metal testing repeat.
It is actually kind of interesting in a very geeky science way.
Re:terminator (Score:3, Informative)
It works with Keanu Reeves.
Having seen several Keanu films... no it doesn't.