Slashdot Mirror
Transparent Aluminum a Reality
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."
Grr...
See also here for earlier developments in this area.
Opportunity knocks. Karma hunts you down.
Surface composition is a big factor in penetration resistance- try slashing open steel plate with chromoly when it's polished versus roughly plasmacut- the rough plate will catch batter.
www.vrogy.com/blog
"[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz
Sapphire which is basically a crystal of aluminium oxide has been synthetised almost 100 years ago and is commonly used nowadays. Some non-scratch watches use that instead of glass.
"A great democracy must be progressive or it will soon cease to be a great democracy." --Theodore Roosevelt
Here's the history behind the difference (from the Wikipedia article):
Scotty doesn't trade the formula for transparent aluminium for a small run of the stuff. He trades for a quantity of perspex.
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.
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.
Humvees normally cost the military about $125,000 each. Installing Level I (the highest) armor costs an additional $125,000. http://www.reflector.com/news/content/shared/news/ world/stories/08/11TROOPS_ARMOR.html/ The article in the link states that the military's goal is to get every Humvee in the fleet to that state of armor. So $16,560 to $24,840 is therefore reasonable for an entire fleet to have.
Thinnish coating of aluminum oxide on glass/plastic multilayer laminate improves its strength and scratch resistance.
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.
It is not unusual for metals to be increased in strength after polishing or grinding, as a method of stress relief. Ceramics, while beyond my experience, are likely similiar.
IIRC, the whale enclosure was made of plexiglass. They bought it with the formula for transparent Al, but the manufacturer wouldn't have had time to tool up to make the new material.
"In a June 2004demonstration, an ALONtm test pieces held up to both a .30 caliber Russian M-44 sniper rifle [...]"
Never trust a journalist to get gun facts straight.
The M44 is a carbine version of the Mosin-Nagant, 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. The M44 has a short barrel so a steel-cored 7.62x54R 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 would be likely to have handy.
Scotty didn't exchange the formula for a small run of transparent aluminum, it would have taken years for the plant to study the formula and tool up their factory to produce the stuff. He traded the formula for a large, thick sheet of plexiglass or similar that the company would have had on hand or actually be able to manufacture at that time.
University - a box of academia nuts.
the website of the TM and Patent holder
http://www.surmet.com/alon.html
This story is starting to become almost a yearly tradition on Slashdot.
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
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
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.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
I would think that some compound containing aluminium is as close to transparent aluminium that we'll ever get.
To be fair this is a different material than the previous two articles, the first two describe an alumina glass, whereas this article describes an aluminum oxynitride ceramic.
To be even fairer, alumina isn't alumin{i}um and neither is alumin{i}um oxynitride, but all the headlines imply that it is.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Anything is transparent if you make it thin enough. Weren't the early space helmet visors gilded?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Polishing (like case hardening) belongs to a normal metallic property called work hardening. You work a metal it will become harder (but normally also more brittle). In fact it is rarer to have a metal that won't work harden than not. Time to go back to metal shop!!
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.
Of all the Universal Constants, here's one I know: Nice guys finish last
ask and you shall recieve.
/C 30-200C: 5.65x10-6; 30-400C: 6.40x10-6 30-600C: 6.93x10-6; 30-900C: 7.50x10-6 .633 m, 1.777 @ 1.06 m 1.722 @ 3.39 m, 1.653 @ 5 m (Note: Refractive Index is composition dependent)
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
Actually, no. Current ceramic rifle plate technology for human-worn body armor does not shatter when hit with a single round. See here.
"In 1808, Humphry Davy originally proposed the name alumium while trying to isolate the new metal electrolytically from the mineral alumina. In 1812 he changed the name to aluminum to match its Latin root. The same year, an anonymous contributor to the Quarterly Review, a British political-literary journal, objected to aluminum, and proposed the name aluminium."
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.
This story is starting to become almost a yearly tradition on Slashdot.
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.
They have a pic on their photo page at http://www.af.mil/photos/index.asp:
.30 caliber armor-piercing bullet fired from 25 yards away using a Russian M-44 sniper rifle. Shown is the test piece, which demonstrates the armor's ability to stop penetration from armor-piercing threats. (U.S. Air Force photo)
Low-res and high-res.
Cutline:
WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- This ground-finish transparent armor test piece withstood the impact of a
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.
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.
Aah, change is good. -- Rafiki
Yeah, but it ain't easy. -- Simba
Transparent Aliminum has been around for all our lifetimes: Sapphire = Aluminum Oxide. My watch has a sapphire crystal... Yours might too.
Well, according to the article, the aluminum took armor piercing rounds from a 50 cal Browning Sniper rifle without breaking like the glass armor did. Also it weighs less, it doesn't scratch as much, (providing better visibility), it has a longer lifetime so it doesn't have to be replaced as often and therfore may be cheaper in the long run. Read the article next time - it answers a lot of your questions.
so you are saying it all worked out as planned?
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.
[i have an opinion and i am not afraid to use it]
Quote: in both [English and Latin], the spoken words are emitted from the caudal orifices of the speakers
Have you stopped to think what a caudal 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!