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Maybe Scotty DID alter the timeline
Topic Started: Jun 3 2005, 09:41 PM (312 Views)
Dwayne
Profanity deleted by Hoss
Quote:
 
Glass breakthrough

Scientists in the US have developed a novel technique to make bulk quantities of glass from alumina for the first time. Anatoly Rosenflanz and colleagues at 3M in Minnesota used a "flame-spray" technique to alloy alumina (aluminium oxide) with rare-earth metal oxides to produce strong glass with good optical properties. The method avoids many of the problems encountered in conventional glass forming and could, say the team, be extended to other oxides (A Rosenflanz et al. 2004 Nature 430 761).

Glass is formed when a molten material is cooled so quickly that its constituent atoms do not have time to align themselves into an ordered lattice. However, it is difficult to make glasses from most materials because they need to be cooled -- or quenched -- at rates of up to 10 million degrees per second.

Silica is widely used in glass-making because the quenching rates are much lower, but researchers would like to make glass from alumina as well because of its superior mechanical and optical properties. Alumina can form glass if it is alloyed with calcium or rare-earth oxides, but the required quenching rate can be as high as 1000 degrees per second, which makes it difficult to produce bulk quantities.

Rosenflanz and colleagues started by mixing around 80 mole % of powdered alumina with various rare-earth oxide powders -- including lanthanum, gadolinium and yttrium oxides. Next, they fed the powders into a high-temperature hydrogen-oxygen flame to produce molten particles that were then quenched in water. The resulting glass beads, which were less than 140 microns across, were then heat-treated -- or sintered -- at around 1000°C. This produced bulk glass samples in which nanocrystalline alumina-rich phases were dispersed throughout a glassy matrix. The new method avoids the need to apply pressures of 1 gigapascal or more, as is required in existing techniques.

The 3M scientists characterised the glasses using optical microscopy, scanning electron microscopy, X-ray diffraction and thermal analysis, and tested the strength of the materials with hardness and fracture toughness tests. They found that their samples were much harder than conventional silica-based glasses and were almost as hard as pure polycrystalline alumina.

Moreover, over 95% of the glasses were transparent and had attractive optical properties. For example, fully crystallized alumina-rare earth oxide ceramics showed high refractive indices if the grains were kept below a certain size.
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Dwayne
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Now imagine that ... transparent aluminum. And it sounds like from the process being used, that transparent steel, titanium and other materials are just over the horizon.
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DEFIANT
Commodore
Very intresting that they may have a new glass-like material. But did the article mention what's good about it (I read it, but I didn't see any mention)?
Will it be cheaper? Can it be 1 inch thick at 60 feet by 10 feet to withstand the pressure of 18,000 cubic feet of water instead of 6 inches?
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Dwayne
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DEFIANT
Jun 4 2005, 02:31 AM
Very intresting that they may have a new glass-like material. But did the article mention what's good about it (I read it, but I didn't see any mention)?
Will it be cheaper? Can it be 1 inch thick at 60 feet by 10 feet to withstand the pressure of 18,000 cubic feet of water instead of 6 inches?

Near the bottom of the article ...
Quote:
 
The 3M scientists characterised the glasses using optical microscopy, scanning electron microscopy, X-ray diffraction and thermal analysis, and tested the strength of the materials with hardness and fracture toughness tests. They found that their samples were much harder than conventional silica-based glasses and were almost as hard as pure polycrystalline alumina.

Moreover, over 95% of the glasses were transparent and had attractive optical properties. For example, fully crystallized alumina-rare earth oxide ceramics showed high refractive indices if the grains were kept below a certain size.

In other words, this stuff is almost as tough as traditional alumina (aluminum oxide) used in say, watches and electronics. What unique about this isn't the product itself, but the method used to manufacture it.
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DEFIANT
Commodore
Thanks.
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Fesarius
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Admiral
Quote:
 
Can it be 1 inch thick at 60 feet by 10 feet to withstand the pressure of 18,000 cubic feet of water instead of 6 inches?

Defiant,

Is that the transparent aluminum equation?
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DEFIANT
Commodore
^^^
Yes, I looked up the script just for that. What a waste of time...but somebody noticed......
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Dwayne
Profanity deleted by Hoss
Just to be clear, this isn't actually transparent aluminum, it's more like a ruby. But the process will allow them to make sheets of this stuff in very large quantities and it will be super strong compared to glass made of silica.
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Fesarius
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Admiral
Dwayne,

Thanks.

Defiant,

Yes, I notice many things on this Board--even when I don't comment on them. Like your Spacely Space Sprocket reference in the other thread--it ain't gettin' by me. ;)
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Dwayne
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Fes ... you are always welcome.
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Fesarius
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Admiral
^^^
Dwayne,

Thanks. Those are kind words. :yes:
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captain_proton_au
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A Robot in Disguise

I wonder how malleable it would be?

That is, will be see car bodies made from this stuff.

A see-through car would be cool
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Ngagh
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Huh?
captain_proton_au
Jun 4 2005, 03:53 PM
A see-through car would be cool

Now that would be cool.
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Ngagh
Jun 4 2005, 10:22 PM
captain_proton_au
Jun 4 2005, 03:53 PM
A see-through car would be cool

Now that would be cool.

Not if you wanted some back seat action.
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captain_proton_au
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A Robot in Disguise

Or you used the floor as a garbage bin
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