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
s 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.
