Transparent Aluminum a Reality 759
TuballoyThunder writes "Many of us remember the scene from Star Trek IV where Scotty barters the formula for transparent aluminum for a small run. It now appears that we can now add transparent aluminum to the science fact column."
Aluminium! (Score:3, Informative)
Transparent Alumin(i)um (Score:4, Informative)
Re:Super Polish (Score:1, Informative)
www.vrogy.com/blog [vrogy.com]
Note to mods: (Score:5, Informative)
Sapphire (Score:5, Informative)
Other things realizable by R-ing TFA (Score:5, Informative)
Re:How's it pronounced? (Score:5, Informative)
Here's the history behind the difference (from the Wikipedia article [wikipedia.org]):
Bad Trek Trivia (Score:4, Informative)
Dr. Nichols says it'll take him "years to even calculate the matrix". Besides that, the stuff they delivered and installed was clearly perspex - it would have been much thinner had it been transparent aluminium.
Re:Aluminium! (Score:1, Informative)
Re:Humvee Windshields (Score:3, Informative)
That's DoD prices, they always seem to have a zero more than seems reasonable, sometimes more. (there's been a few $500 toilet-seats and $300 hammers)
The current prices for similar glass-armor are quite high too, at $3 or so a square inch that Hummer windshield is still going to cost around $5000.
Re:Humvee Windshields (Score:5, Informative)
No news here (Score:3, Informative)
News for non chemical nerds, maybe. A bit ho hum for anybody familiar with the AMAZING see through properties of things like aluminumium oxide, aka rubies and saphires.
Re:Super Polish (Score:2, Informative)
Re:Aluminium! (Score:3, Informative)
Re:Aluminium! (Score:2, Informative)
Re:nearly, but not quite... (Score:2, Informative)
M-44 sniper rifle? (Score:5, Informative)
Never trust a journalist to get gun facts straight.
The M44 is a carbine version of the Mosin-Nagant [wikipedia.org], very short, easy to carry, but with nothing better than iron sights. It is about as far from a "sniper rifle" as anything you can see.
It has the coolest integral bayonet, though.
On the upside, the M-44 uses the same cartridge as the current Romanian "sniper" rifle, the PSL [wikipedia.org]. The M44 has a short barrel so a steel-cored 7.62x54R [wikipedia.org] projectile won't reach the same sort of velocities as it would out of a PSL rifle but it should be a pretty effective test against the sort of "armor piercing" light arms that any terrorist not carrying an RPG [wikipedia.org] would be likely to have handy.
Not quite correct (Score:4, Informative)
If anybody cares.... (Score:1, Informative)
http://www.surmet.com/alon.html [surmet.com]
Re:A Great Send-Off (Score:5, Informative)
Transparent Aluminum a Reality
On October 18th, 2005 with 231 comments
TuballoyThunder writes "Many of us remember the scene from Star Trek IV where Scotty barters the formula for transparent aluminum for a small run. It now...
Transparent Aluminum Is Here [slashdot.org]
On August 23rd, 2004 with 625 comments
Alien54 writes "Scientists in the US have developed a novel technique to make bulk quantities of glass from alumina for the first time. (link includes a...
Transparent Aluminium [slashdot.org]
On February 20th, 2002 with 368 comments
Lynx writes "As the german magazine Spiegel reports, scientists at the Fraunhofer Institute for Ceramic Technologies have developed a transparent tile made...
And that was from the first page of the search screen ordered by rank.
Re:transparent oxide-nitride, not a metal (Score:3, Informative)
I would think that some compound containing aluminium is as close to transparent aluminium that we'll ever get.
Re:A Great Send-Off (Score:4, Informative)
Re:A Great Send-Off (Score:5, Informative)
Re:transparent oxide-nitride, not a metal (Score:3, Informative)
Re:Super Polish (Score:5, Informative)
Go back? Ok, I'm in one every day.
While you're right about metals work hardening, you're wrong about how often it happens. Quite frankly, it doesn't unless you're either extremely stupid or even more so insane. Even soft magnetics like Cast Iron don't work harden until extremely high temperatures are reached. Something to the tune of 650-1100F, depending on the hardness rating you wish to achieve. If you're reaching temperatures that high before the part is finished, well, you're either cutting it off at the foundry or you're about to be fired. The methods used to actually harden materials in a noticeable fashion are specifically designed to superheat the part. Magnetics such as steel and any iron based material will be heated until red, blue or white hot to achieve hardening. This process is called annealing. Other metals are generally coated with a harder metal, not more than a thousand of an inch or two in thickness; this generally achieves the same affect.
Polishing however, is not generally meant to harden, and rarely does. When a part or surface is polished, part of that surface is actually worn away while polish is deposited. This is the only way to achieve mirror finish, if the part has been turned or faced the surface will have markings on it from the tools used to cut it. Polishing is the process of actually wearing away material to relieve the markings, and depositing polish to increase shine. People should note that the more reflective a metal surface is, the finer the finish. Mirror finish generally denotes a "256 dp finish", required often by aerospace or military applications. The dumbass of a parent knows nothing of what he's talking about, and needs himself to open up a machinist's handbook.
Re:Refractive index? (Score:1, Informative)
ALON
Density (g/cc) 3.688
Lattice Constant (Å) 7.946
Structure Cubic Spinel; Al(64+x)/3O32-xNx (2.75 x 5 )
Typical Grain Size (m) 250
Young's Modulus (GPa) 334
Shear Modulus (GPa) 135
Knoop Hardness (kg/mm2) 1800±74 @200 g load
Poisson's Ratio 0.239
Transmission Range (mm) 0.2 to 6.0
Fracture Toughness (MPa-m½) 2.0
Flexural Strength (MPa) 380 ± 34
Specific Heat (cal/g-C) 0.22
Compressive Strength (MPa) 2677
Thermal conductivity (W/m-K) 9.62 @75C; 7.11@270C 6.3@540C and 7.11@830C Thermal Expansion Coefficient
Index of Refraction (n, ) 1.790 @ 0
Dielectric Constant and Loss Factor (@1GHz) k = 9.19, tan = 31x10-5
Re:Actually this is a ceramic - nothing really new (Score:3, Informative)
No, you're wrong (Score:4, Informative)
So aluminum was the first spelling, which was later change by language nazis because it didn't sound right.
Don't blame us Americans for trying to be historically accurate.
Re:A Great Send-Off (Score:1, Informative)
It's worse than that: since each repost occurs at half the previous interval, we'll see the same story in January and March, with a singularity arising in October 2006.
Photo available (Score:2, Informative)
Low-res [af.mil] and high-res [af.mil].
Cutline:
WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- This ground-finish transparent armor test piece withstood the impact of a
Re:Aluminium Reality or Aluminum Realty? (Score:1, Informative)
Re:Super Polish (Score:3, Informative)
Or you're working a part by hand. Or the part does duty in a high vibration environment (copper fuel line are verboten on small airplanes for just this reason). Or you bend a heat treated nose gear on a hard landing and then try to bend it back into place.
It doesn't happen often in a machine shop, unless the machinist is explicity trying to do it, but metalsmiths all over the world take advantage/try to avoid work hardening in various situations.
BTW, a technical definition used in a machine shop may not be the common usage in the rest of the world. To the general world that I've been exposed to, work hardening is any increase in the hardness/brittleness derived from the stretching and shrinking involved in getting the metal to the desired shape. In this aspect, the gp is not necessarily off base. A stainless steel slapper is often used to 'polish' aluminum fairings, and the aluminum is harder after the process.
Sapphire is transparent Aluminum (Score:5, Informative)
Re:You joke, but... (Score:3, Informative)
Re:Humvee Windshields (Score:2, Informative)
i don't think they'd need better homvee windshields if it did.
and why would the corporations bombed into control of the oil fields be that much interested in lower oil prices? besides, the oil business is a very slow one, you don't just drive by with a tank and take away all the oil, even rebuilding previously existing infrastructure takes many years, more if you have to deal with partisan activity.
Re:Aluminium Reality or Aluminum Realty? (Score:3, Informative)
Have you stopped to think what a caudal [wordreference.com] orifice is, or where is it located?
Now I understand why I always have this funny accent when speaking English... in my mother language, the spoken words are just emitted from the mouth of the speakers. So many years attending language courses, and nobody ever told me!