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View Full Version : transparent aluminum(star trek) is real !!!



dan s
01-09-2009, 01:57 AM
I was watching "how stuff works" tonight and the has a segment on transparent aluminum. :eek: I thought it was just something they made up for star trek, but its real.

http://en.wikipedia.org/wiki/Aluminium_oxynitride

tony ennis
01-09-2009, 01:59 AM
Yep. And when you anodize aluminum, you're really converting the surface to a thin layer of sapphire.

lazlo
01-09-2009, 02:00 AM
That's pretty cool, but the Wiki links to an Air Force article from 2005.
So have they had transaparent aluminum armor for almost 4 years now? :)

http://www.af.mil/news/story.asp?id=123012131

dan s
01-09-2009, 02:03 AM
So have they had transaparent aluminum armor for almost 4 years now? :)

http://www.af.mil/news/story.asp?id=123012131

how stuff works said they are still testing, but they said it could stop a 50 cal round. I think I caught the tail end of the demonstration video (walked out to the shop, to check on the ban saw).

dan s
01-09-2009, 02:15 AM
I found the manufactures technical data sheet, it's a very interesting material. The melting point is so high you could use it for a viewing port on a kiln/furnace.

http://www.surmet.com/docs/Product_sheet_ALON.pdf

lazlo
01-09-2009, 02:23 AM
Reading the Air Force article in more detail, it's not aluminum, it's an aluminum oxide: a.k.a. a derivative of sapphire (saphire = Al2O3 = aluminium oxide).

In other words, it's a transparent ceramic, and not a transparent metal :)

.RC.
01-09-2009, 02:33 AM
Where do you get this Aluminum and does it differ from the much more common Aluminium??? :D

Bruce Griffing
01-09-2009, 02:45 AM
As Robert points out, this material is not metallic. But there are transparent metallic materials. Or to be more proper - degenerate semiconductors. Indium tin oxide (ITO) is an example. Useful because it conducts electricity and is also transparent to visible light. LCD's use it as LC control electrodes. (more recently they use a close relative of ITO).

macona
01-09-2009, 03:53 AM
Germanium is transparent.. To far IR.

airsmith282
01-09-2009, 08:36 AM
i always been interest in communacations and futureistic stuff as well and have found over the years alot of what we see on tv is true in real life and has been for usualy a number of years before we the public get to really see it ,. these days i just laugh off the stuff when i see it on tv and tell the wife look something else that they been hidding again herhee llololol..

Your Old Dog
01-09-2009, 09:13 AM
Reading the Air Force article in more detail, it's not aluminum, it's an aluminum oxide: a.k.a. a derivative of sapphire (saphire = Al2O3 = aluminium oxide).

In other words, it's a transparent ceramic, and not a transparent metal :)

Maybe so but they billed it last night on the program as transparent aluminum. I saw the program myself and found confirmation in what various guys here have said about cleaning aluminum and that it starts to oxidize post haste causing problem with those "wonder rods" used for welding/brazing it.

Circlip
01-09-2009, 09:49 AM
Yep, and the Bling King's favourite -- Chrome is transparent.

Regards Ian.

Lew Hartswick
01-09-2009, 10:34 AM
Reading the Air Force article in more detail, it's not aluminum, it's an aluminum oxide: a.k.a. a derivative of sapphire (saphire = Al2O3 = aluminium oxide).

In other words, it's a transparent ceramic, and not a transparent metal :)
Just EXACTLY as window glass is a transparent form of silicon.
So what is the big deal??? :-)
...lew...

loose nut
01-09-2009, 10:51 AM
Want something cooler from "Star trek".

The British are working on electromagnetic shielding for there armored vehicles, saw it on one of those future weapons type shows.

They fired a shaped charge at it, might have been an RPG 7, can't remember for sure, but it barely scratched the paint. The E/M shielding disrupts the formation of the gas jet when the weapon detonates so there is just a regular blast with no penetration.

Beam me up Scotty!

Evan
01-09-2009, 10:54 AM
The big deal is that it combines extreme hardness with extreme shatter resistance which is a very rare combination and makes it suitable as transparent armour. It has been shown to resist multiple 50mm impacts in a form entirely suitable for use as a windshield or aircraft canopy.

It isn't aluminum oxide but aluminum oxynitride.

lynnl
01-09-2009, 02:19 PM
Yeah I also watched that program last night. Very interesting. Covered everything from mining the bauxite to several finished products, as well as some of the ongoing R&D.
They also showed some aluminum foam panels being developed to withstand explosive forces (e.g. IED's in Iraq).

I recall a lively discussion here some time ago about aircraft aluminum. One segment showed a huge Alcoa plant in Davenport Iowa that rolled down big 12" thick slabs (billets) into aircraft wing skin panels. One of the plant reps said the skins are all the 70 series aluminum ...at least the upper surface, he didn't say what the bottom skin is, but implied it was a different alloy. No mention was made of the fuselage skin, nor wing spars or other structural members. (The acft in question was a Boeing 777 btw)

Another interesting feature was some $121K aluminum engines for the drag racing market carved (CNC) out of billets (there's that word again). I think they said they produced something over 2000 hp. Was surprised to see one guy manually lifting a V8 block to put it into the heat treat oven. ...course he was a pretty husky guy. It didn't show how they get the coolant passages cut through the block. That's a puzzle to me.

If you get the chance to watch that, I'm sure any member here would enjoy the program.

quasi
01-09-2009, 03:12 PM
50mm???????? I think you maybe mean .50 cal. A 50mm is the caliber of the rapid fire cannon on the front of Canada's frigate's.

lathehand
01-09-2009, 03:39 PM
Drag race engines often have no cooling passages. They run for such a short length of time they don't overheat. Some production blocks that are used have their passages filled with epoxy to gain strength.
I did machine work for a guy who raced.

John Stevenson
01-09-2009, 03:51 PM
You know what this means ?

Transparent BILLET :eek:

.

loose nut
01-09-2009, 04:47 PM
How would you ever find them :eek: :eek: :eek:

lynnl
01-09-2009, 05:02 PM
Drag race engines often have no cooling passages. ....

I did not know that.
(...there's probably something else I don't know, but I don't know what it might be.)

lazlo
01-09-2009, 05:20 PM
You know what this means ?

Transparent BILLET :eek:

If it were transparent aircraft billet, I'd be more impressed :p

Evan
01-09-2009, 05:34 PM
I did mean 50 cal, not 50mm. I think in metric a lot these days as that is what I use on the CNC mill. However, I am trying to imagine a tank with picture windows in the turret.


One of the plant reps said the skins are all the 70 series aluminum ...at least the upper surface, he didn't say what the bottom skin is, but implied it was a different alloy

There are several 7000 series alloys that have been developed to overcome the problems with 7075. The difference between 7000 series and 2000 series is that the 2000 series is primarily alloyed with copper and the 7000 series with zinc.

ckelloug
01-09-2009, 05:51 PM
Actually, I saw a research article about making aluminum transparent many years ago. The effect only works for a very small area (which may have only been a few atoms) and for a very short time so I suppose it's not actually transparent aluminum in the sense we think of it from the star trek episode.

The effect was based on this: If you bombard a tiny sample of aluminum with a laser of some wavelength (It's been years so I have no idea which one) then the majority of the valence electrons are kicked to higher energy levels. Because they are not in the ground state, they are temporarily unable to absorb photons of the wavelengths in visible light which would normally be absorbed. The aluminum remains transparent until the electrons come back down by emitting photons of whatever wavelength they emit.

So, real aluminum can be made transparent temporarily, it's just that the effect is extremely transient and over a very small area.

--Cameron

darryl
01-09-2009, 06:41 PM
I'm waiting for the bendable ceramic alloys to come out. No more broken coffee cups:)

Evan
01-09-2009, 09:07 PM
You mean this?

http://www.news.cornell.edu/releases/March02/Wiesner.materials.deb.html

philbur
01-09-2009, 09:31 PM
Nice one:)

Phil


I did not know that.
(...there's probably something else I don't know, but I don't know what it might be.)