Translucent concrete and now transparent Aluminum

[g__day]

A ceramic research lab in Dresden, Germany, has developed transparent Alumina by subjecting fine-grained (I'm guessing extremely fine-grained) aluminum to a whopping 1200 degrees Celsius ...the result of which is amazingly light but three times tougher than hardened steel of the same thickness, and it's see-through

http://www.rense.com/general20/transparentalum.htm

and only this morning tanslucent concrete!

http://optics.org/articles/news/10/3/10/1

Light transmitting concrete is set to go on sale later this year.

The days of dull, grey concrete could be about to end. A Hungarian architect has combined the world’s most popular building material with optical fiber from Schott to create a new type of concrete that transmits light.

Letting the light in

A wall made of “LitraConâ€￾ allegedly has the strength of traditional concrete but thanks to an embedded array of glass fibers can display a view of the outside world, such as the silhouette of a tree, for example.

“Thousands of optical glass fibers form a matrix and run parallel to each other between the two main surfaces of every block,â€￾ explained its inventor Ã￾ron Losonczi. “Shadows on the lighter side will appear with sharp outlines on the darker one. Even the colours remain the same. This special effect creates the general impression that the thickness and weight of a concrete wall will disappear.â€￾

 

[zidane1strife]

Interesting materials. Hopefully these are cheap enough to allow for quick widespread use.

 

[Tagrineth]

Dude.

Star Trek IV.

 

[Nathan]

A ceramic research lab in Dresden, Germany, has developed transparent Alumina by subjecting fine-grained (I'm guessing extremely fine-grained) aluminum to a whopping 1200 degrees Celsius ...the result of which is amazingly light but three times tougher than hardened steel of the same thickness, and it's see-through

They appear to be a bit confused. Toughness is a measure of the ability of a material to absorb impacts. Ceramics suck at absorbing impacts. Steel varies from being very good to being very bad. It's quite likely they meant it was three times as hard as steel, which wouldn't surprize me (Though it's still quite a meaningless comparison). Titanium nitride and other similar compounds have been used been used on cutting tools for years because their exceptional hardness improves tool life dramatically.

 

[pax]

I had read about transparent aluminium a while back... bout a year or 2 ago...

 

[Nathan]

The only practical application I can think of for this is some sort of uber anti-scratch coating. You certainly couldn't use it for bullet proof windows. :?

 

[g__day]

Who knows if they meant toughness or hardness - but if it is say 3 times stronger or tougher than say peralite steel that is very, very impressive!

It all depends on its crystaline structure and if it can be further doped I guess.

 

[pax]

Cd's and dvd's sure could use some help!... Where are those new tdk discs that are scratch proof supposedly???

 

[PC-Engine]

This transparent aluminum sounds like it could be sprayed on to surfaces using plasma coating. There's already diamond coated tweeter domes using plasma spraying available among other applications. I guess this aluminum could be a cheaper substitute. Maybe even as a clearcoat on automotive or aircraft paint finishes. Also since it's aluminum it can also aid in heat dissipation on the exterior of aircraft.

 

[Nathan]

Who knows if they meant toughness or hardness - but if it is say 3 times stronger or tougher than say peralite steel that is very, very impressive!

It all depends on its crystaline structure and if it can be further doped I guess.

It couldn't be toughness. Materials with high toughness absorb impact energy by plastically deforming. Ceramics, by their nature, are brittle, so they will always have low toughness. Generally speaking, toughness and hardness are complete opposites

 

[kyleb]

Cd's and dvd's sure could use some help!... Where are those new tdk discs that are scratch proof supposedly???

probably locked away in some riaa vault as it would hurt sales.

 

[RussSchultz]

Generally speaking, toughness and hardness are complete opposites

No wonder why jello wiggles so: it is a cosmic contradiction.

 

[Nathan]

No wonder why jello wiggles so: it is a cosmic contradiction.

 

[g__day]

Nathan

Agree totally, but plastic and elastic deformation abilities depend on a material crystaline lattice and slip planes. If the Alumina oxide had the right crystaline structure it could be an amazing product whose abilities go far beyond hardness.

So if they now have hardness and clarity and they just need flexibility / toughness we could see some wonder uses come out for this material.

I wonder how hard it is to machine and/or weld - possible a complete nightmare requiring laser cutters.

 

[Nathan]

It's not just the lattice and slip planes, but also the bond type. I'm not an expert on this, so I'll have to enlist Google to help me.

http://www.mmat.ubc.ca/courses/mmat382/sections/cnc741.doc
http://www.mmat.ubc.ca/courses/mmat382/sections/cnc743.doc

As mentioned in the first document there are actually ceramics that will plasticly deform, which I wasn't aware of. But I can't imagine they'd ever be ductile enough to be considered tougher than steel.

 

[MfA]

That doc suggests plasticity will increase with decreasing grain size (this reminds me a bit of high carbon steel). Question is, how far can you take that effect?

 

[bloodbob]

Umm Transparent alumina isn't very new since of course it occurs naturally you can see through rubies can't you? please note they have other metal cations in them that give rubies their colour ( Cr 3+).

 

[MfA]

Applications of translucent (polycrystalline alumina seem abundant after a little googling ... so maybe they really did meant toughness, otherwise it is hard to see what was so novel about it.

 

[Nathan]

That doc suggests plasticity will increase with decreasing grain size (this reminds me a bit of high carbon steel). Question is, how far can you take that effect?

To the nanoscale, apparently. Though the results seem mixed here.

http://www.wtec.org/loyola/nano/06_02.htm

 

[Nathan]

Applications of translucent (polycrystalline alumina seem abundant after a little googling ... so maybe they really did meant toughness, otherwise it is hard to see what was so novel about it.

But we're still left with an almost meaningless comparison. Steel has such a huge range of toughness. Hell, all you have to do is stick mild steel in liquid nitrogen and it'll break like glass when you hit it.