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Morphing Metals
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."
Are we to expect a slew of articles about 80 year old discoveries now?!
SMAs have been well known about for decades, well written about for decades, just what is the point if this article?!
People should not be afraid of their governments - Governments should be afraid of their people.
The point:
"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
“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."
Fandroids hate facts.
Are you kidding me? I use Nitinol (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. That is what allows me to bend my frames in all kinds of weird ways without having the metal permanently deform.
Nitinol is also used many permanent implantable medical devices such as stents http://www.euroflex-gmbh.de/pdfs/medical.pdf [PDF] and having developed a few devices with Nitinol, it is simply amazing to see it work.