Transparent aluminum armor

Air Force testing new transparent armor

A lot of folks have noted this already, but a reader tipped me off and I finally looked into it a bit more. Of course, a lot of folks are bringing up Scotty and the transparent steel used in Star Trek IV, so I won’t even bother mentioning it here. Here’s what we’re (not) looking at:

The new armor combines the transparent ALONtm piece as a strike plate, a middle section of glass and a polymer backing. Each layer is visibly thinner than the traditional layers.

ALONtm is virtually scratch resistant, offers substantial impact resistance, and provides better durability and protection against armor piercing threats, at roughly half the weight and half the thickness of traditional glass transparent armor, said the lieutenant.

In a June 2004 demonstration, an ALONtm test pieces held up to both a .30 caliber Russian M-44 sniper rifle and a .50 caliber Browning Sniper Rifle with armor piercing bullets. While the bullets pierced the glass samples, the armor withstood the impact with no penetration.

In extensive testing, ALONtm has performed well against multiple hits of .30 caliber armor piercing rounds — typical of anti-aircraft fire, Lieutenant La Monica said. Tests focusing on multiple hits from .50 caliber rounds and improvised explosive devices are in the works.

The lieutenant is optimistic about the results because the physical properties and design of the material are intended to stop higher level threats.

“The higher the threat, the more savings you’re going to get,” he said. “With glass, to get the protection against higher threats, you have to keep building layers upon layers. But with ALONtm, the material only needs to be increased a few millimeters.”

The stuff is still very difficult to make and costs about four or five times as much a traditional glass armor. Even at that price, though, it will still be worth it for many applications. One thing that might help mitigate the high cost is the stuff’s resistance to scratching. In Iraq, for instance, windshields on armored Humvees need to be replaces when sand damage renders them unusable. If this ALONtm can outlast four or five standard windshields, it’s already worth it economically even if you discount the advantage of weight, which is substantial.


  1. I wonder if it can be moulded? (I imagine so, regular Aluminium can). If so, it’d be perfect for aircraft canopies and windows. Bird-proof and bullet-proof. I guess the other question is, will curved sections of it distort the image behind it? That’s another issue for fighter canopies. Compared to the cost of a plane, it seems the cost of using this material for canopies and windows would be negligible.

  2. I wonder if it can be moulded? (I imagine so, regular Aluminium can).’ I think calling this stuff Aluminum is a misnomer. It really sounds more like a clear ceramic, with some Aluminum mixed in. The techniques for manufacturing it and bending it would be more similar to glass than to metal. Somewhere else I read that manufacturing bent pieces could be tricky, and early applications would likely be for flat pieces. IIRC, the wording was that its possible to manufacture curved pieces, but hard (i.e. expensive).

  3. BTW, as a closet Trekker, I gotta say this. In ST-IV, they WERE talking about ‘transparent aluminum’ as stated by the disbeliving gentleman in the polymers company.