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UCLA Creates Super-Strong, Super-Light Metal (ucla.edu)
An anonymous reader writes: Engineers working on planes, rockets, and other vehicles are always looking for new metals to make their creations lighter and stronger. A new invention from UCLA demonstrates "record levels of specific strength — how much weight a material can withstand before breaking — and specific modulus — the material's stiffness-to-weight ratio." The metal is mostly (86%) magnesium, but infused with an even dispersal of ceramic silicon carbide nanoparticles (abstract). A key part of their work was preventing the nanoparticles from clumping, since they attract each other if left alone. "To counteract this issue, researchers dispersed the particles into a molten magnesium zinc alloy. The newly discovered nanoparticle dispersion relies on the kinetic energy in the particles' movement. This stabilizes the particles' dispersion and prevents clumping."
This stuff has limitless possibilities. Everything from knives to bumpers to bike frames....the list of potential applications is endless.
Better cellphone cases. Better engines and electric motors. Better ballistic armor. Better tools. Better antennas. Better vehicles that fly/float/roll.
Just cruising through this digital world at 33 1/3 rpm...
Uh, you would be wrong...
My wife and I had one of the grilles in this series. We got the recall notice right after thoroughly cleaning the grille for the first time. Normally the inside of the chamber is protected by a layer of oxidation, but a thorough cleaning scrapes the oxide layer off and exposes fresh magnesium. Ours didn't catch fire, but after we got the recall notice we looked into it and apparently the first heavily-documented case of the grille burning was after the owners thoroughly cleaned it and probably exposed fresh magnesium right before using it again.
Magnesium is used successfully for other applications, but usually with the fire-risk considered an acceptable tradeoff. Engine blocks, with steel liners for the cylinder walls and with aluminum cylinder heads so that the magnesium isn't directly exposed to flame, and in wheels that should be safe unless a tire failure results in a skidding bare wheel scraping against pavement are both common in racing. The very term, "mag wheel," is based on the use of magnesium wheel, even if most are now aluminum for street-legal uses.
For the right applications this alloy could be very good. Just don't make barbecue grilles out of it.
Do not look into laser with remaining eye.
the bulk metal is difficult to ignite.
Magnesium alloys are very good heat conductors so applying flame to one area of a large solid piece of magnesium alloy won't ignite it, any more than, say, aluminium alloy materials as the heat is ducted away from to contact point. On the other hand magnesium powder, thin ribbon or wire will burn without too much effort.
Acquaintances of mine who put some magnesium-alloy aircraft wheel hubs in a bonfire were somewhat disappointed by the lack of performance until one of them rigged up a feed of pure oxygen into the bonfire at which point they lit off quite nicely.
According to the Wikipedia article on Magnesium rims, the bulk metal is difficult to ignite. This mirrors my own experience - it's hard to ignite a strip of magnesium for a chemistry demonstration.
The power tools were off limits without supervision when I went to high school. This apparently became a hard rule a few years before, when the shop teacher walked in on a student who had a magnesium automotive wheel in the lathe, and was up to his knees in magnesium ribbon, in the form of long, curly shavings.
Yes, it's hard to light, but ribbon is much easier to get going than a block, and there's a lot of heat from metal working. (I hear one way to light a block is to curl up a tapered shaving and light the end of it.) Once it's lit it's nearly impossible to extinguish. (It burns in water, for instance, sucking out the oxygen and releasing hydrogen. It burns in carbon dioxide, similarly releasing a black cloud of carbon dust. Hit it with either of those types of extinguisher and it just gets more violent.) If the kid had managed to light those shavings they'd have tangled in his pants and followed him around as he tried to escape.
(I haven't tried it, but I bet an electric arc would light off a block of magnesium just fine...)
This stuff might be somewhat safer: I'd expect the nanoparticles to interfere with making long, thin, shavings.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way