Forty years ago, a patent was issued by the United States Patent and Trademark Office, for a “Process for producing polycrystalline cubic aluminum oxynitride”; US Patent 4,241,000. It must have been a Christmas gift to the US Army, as the application was granted on December 23, 1980. The world’s toughest ceramic material has since been used extensively in military applications including optics, armored windows, and sensor domes such as those on heat-seeking missiles and laser-guided bombs.
Aluminum oxynitride was created by Raytheon Corporation for the Army, but today it is manufactured by Surmet Corporation and marketed as ALON. It is no doubt better known to the public as “transparent aluminum” thanks to the movie Star Trek IV: The Voyage Home (1986). You remember – Scotty and Dr. McCoy exchange the formula of see-through aluminum for enough plexiglass to build an aquarium tank large enough to transport two humpback whales into the future aboard their captured Klingon starship.
The process set forth in the patent application described a new ceramic alloy made of a mixture of the elements aluminum, oxygen, and nitrogen (not strictly aluminum despite what the moniker “transparent aluminum” suggests). The end product is as transparent as glass, but lighter and four times stronger. It’s also nearly as hard and scratch-resistant as sapphire (chemical formula: aluminium oxide). A relatively thin 1.6 inch thick pane of aluminum oxynitride can stop a .50 BMG (Browning Machine Gun) caliber bullet. Bullet-resistant glass (often incorrectly called bullet-proof glass) more than twice as thick (3.7 inches) cannot.
The big question is, after forty years why don’t we see ALON in civilian commercial products? The answer is cost, with ALON being several times more expensive than bullet-resistant glass. Hopefully, we’ll see the day when everyday things like eyeglasses and safety goggles are made with ALON. The one product I really want ALON in is smartphones, both the front display screen and back side of the phone. I’m tired of busted display screens: I want a phone that’s rugged enough to fall three or four feet onto concrete and survive unscathed.
Please enjoy this obligatory video; “Transparent Aluminum – Star Trek Technology is now Real” (3:49):
Question of the Night: What product(s) would you like to see made with
transparent aluminum?
