The US Air Force Research Laboratory at Wright-Patterson Air Force Base is testing a new kind of transparent armor, clear aluminum aluminum oxynitride, that can stop hardcore .30 and .50 caliber armor-piercing bullets. From a press release:
ALONtm is a ceramic compound with a high compressive strength and durability. When polished, it is the premier transparent armor for use in armored vehicles, said. 1st Lt. Joseph La Monica, transparent armor sub-direction lead
“The substance itself is light years ahead of glass,” he said, adding that it offers “higher performance and lighter weight.”
Traditional transparent armor is thick layers of bonded glass. 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.