Transparent Aluminum

Aluminum oxynitride or transparent aluminum (marketed under the name ALON by Surmet Corporation) is a transparent ceramic composed of aluminum, oxygen and nitrogen. ALON is optically transparent (≥ 80%) in the near-ultraviolet, visible and midwave-infrared regions of the electromagnetic spectrum. Transparent aluminum was made for various defense applications like sensor windows, transparent armor, windows for laser communications and speciality IR domes with different shapes.

Transparent aluminum is a transparent polycrystalline ceramic with a cubic spinel crystal structure made of nitrogen, oxygen and aluminum. It is four times harder than fused silica glass, 85% harder than sapphire and 15% harder than magnesium aluminate spinel. The material remains solid up to 1200°C (2190°F). It has good corrosion resistance and resistance to damage from radiation and oxidation. The compressive strength of transparent aluminum is 2.68 GPa, Flexural strength is 0.38-0.7 GPa, Fracture toughness is 2 mPa.m^1/2, Knoop hardness is 1800 kg/mm², poisson ratio is 0.24, Shear modulus is 135GPa and the Young modulus is 334GPa.

This wonder material is made from powdered aluminum oxynitride, a pile of white powder. It is poured into a rubber mold (which will depend on whatever shape is desired to be formed) and placed under pressure in a process called isostatic pressing. Oxford scientists have created a transparent form of aluminum by bombarding the metal with the world's most powerful soft X-ray laser. Aluminum armor can deflect the same rounds from small-caliber weapons as traditional bulletproof glass, but it will still be more clearly transparent even after being shot. Transparent aluminum armor can be anywhere from three to five times as much to produce as traditional bulletproof glass.