Transparent Aluminum glass created

[Krimson Klaw]

http://physicsweb.org/articles/news/8/8/9

Glass breakthrough
11 August 2004

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.


Aluminate glasses
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 (see figure) 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.

The link actually has some pictures of the different shades of aluminum glass. This is awesome news that would make Scotty proud. Amazing how sci-fi can drive things in the real world. Thanks Roddenberry!

[Kguku]

So how long before someone transports a whale in a speaceship?

[Akaran_D]

yttrium

Oh how I hated those damn Ssra Temple weapons.

[Niffoni]

Hel-lo computer!

Any word yet on if it's even concievably possible to make a woman with an 80s hairstyle remotely hot?

[miir]

Hel-lo computer!

Any word yet on if it's even concievably possible to make a woman with an 80s hairstyle remotely hot?

Hawt!

[Xatrei]

Pat always scared me.

[Marbus]

IMHO both Star Trek and Star Wars have done a lot for technology during the past 30 years. Why? Because they put the ideas into the minds of children who dream. This is one of those dreams and a very great thing!

Marb

[archeiron]

This article is one of my new favorites. I regret not doing metallurgy instead of stupid electrical engineering!

Another intersting topic (which I believe was covered here) is http://www.liquidmetal.com/technology/

Maybe, I should go back to university and do an M.A!

[Winnow]

Hel-lo computer!

Any word yet on if it's even concievably possible to make a woman with an 80s hairstyle remotely hot?

Oh man, Heather Locklear was a hottie!



She wore 80's hair the best : )

[masteen]

She still is, and she still has that BIG 80's hair!

[Midnyte_Ragebringer]

So how long before someone transports a whale in a speaceship?

ROFL That was my first thought.