[goldendelicious]

Aluminium oxynitride or AlON is a ceramic composed of aluminium, oxygen and nitrogen. It is marketed under the name ALON by Surmet Corporation. AlON is optically transparent (≥80%) in the near-ultraviolet, visible and midwave-infrared regions of the electromagnetic spectrum. It is 4 times harder than fused silica glass, 85% as hard as sapphire, and nearly 15% harder than magnesium aluminate spinel. Since it has a cubic spinel structure, it can be fabricated to transparent windows, plates, domes, rods, tubes and other forms using conventional ceramic powder processing techniques. ALON is the hardest polycrystalline transparent ceramic available commercially. Combination of optical and mechanical properties makes this material a leading candidate for lightweight high-performance transparent armor applications such as bulletproof and blast-resistant windows and for many military infrared optics. AlON-based armor has been shown to stop multiple armor-piercing projectiles of up to 50 cal. It is commercially available in sizes as big as 18x35-inch monolithic windows. ALON can be fabricated as windows, plates, domes, rods, tubes and other forms using conventional ceramic powder processing techniques. Its composition can vary slightly: the aluminium content from about 30% to 36%, which has been reported to affect the bulk and shear moduli by only 1–2%.) The fabricated greenware is subjected to heat treatment (densification) at elevated temperatures followed by grinding and polishing to transparency. It can withstand temperatures of about 2100 °C in inert atmospheres. The grinding and polishing substantially improves the impact resistance and other mechanical properties of armor.

[SMGFan]

1986 film Star Trek IV: The Voyage Home.

https://en.wikipedia.org/wiki/List_of_Star_Trek_materials#Transparent_aluminum

[plain talk]

I love this article and post but it is paragraph challenged. :-).

[House Atreides]

Yes, I remember when Steve Jobs invented it ;-)

[Army Air Corps]

Ping.

[Army Air Corps]

Ping.

[hoagy62]

I wonder if they can use this stuff in spacecraft windows.

[Mr. Blond]

Can it be used to make the domes for Mars colonies?

[SpaceBar]

Aluminum oxide aka sapphire is transparent. A transparent compound with a metallic cation does not constitute a ‘transparent metal’.

[gaijin]

Later

[Boomer]

I wonder when it will be available for cars and motorcycle windshields. Soon I hope and at a price that doesn’t break the bank.

[NappyOne]

Nice images of the ISS cupola. After all these years it will be interesting to see if it can be replaced and what the procedure will be. Last time they redeployed a segment of the ISS was moving the port solar array from the Z1 truss to the P3 truss. You might say they got a few kinks along the way.

The NappyOne

[easternsky]

Welcome to Free Republic

[Nateman]

Sounds like it would be good to use in smart phones.

[fieldmarshaldj]

Has Dr. Nichols cashed in on in his find, yet ?

[Revolutionary]

Actually, this has been around for several years. Good stuff.

[wardaddy]

Cool for canning