Aluminum oxynitride: a transparent ceramic that can be bulletproof

(Aluminum oxynitride: a transparent ceramic that can be bulletproof)

Introduction: Scientists have not found a way to make metal aluminum transparent, but they have developed a transparent aluminum-based material that can achieve similar strength. This product is called aluminum oxynitride (AlON). Its hardness is 4 times that of quartz glass and 85% that of sapphire; AlON with a thickness of about 4cm is enough to block 50-caliber bullets, which is not possible with traditional laminated bulletproof glass. In addition to having strong hardness, it also has good elasticity. These characteristics make aluminum oxynitride have a very broad application prospect in the fields of national defense and aerospace.

Remarks: The use of steel core armor-piercing projectiles can deal with light armored targets with an armor thickness of less than 20 millimeters within 1000 meters, and the use of explosive incendiary bombs can destroy large, high-value targets such as radars and aircraft at a distance of 1500 meters. Using aluminum oxynitride bulletproof ceramics to replace bulletproof glass can reliably resist the destruction of military or other important equipment by sniper rifles or destroying objects at a smaller thickness and lower weight. The following will briefly explain the basic properties, preparation process progress and application of AION ceramics. 1. The performance of aluminum oxynitride ceramics 1. The basic characteristics of aluminum oxynitride. Aluminium oxynitride (γ-AlON, AION for short) is a kind of transparent polycrystalline ceramics. It is a brand-new polycrystalline infrared material. Infrared has high optical transmission performance. Its biggest advantage is that it has optical isotropy, and has good light transmittance in the mid-infrared band (transmittance of more than 80% in the wavelength range of 0.2 to 6.0 μm), and aluminum oxynitride also has good physical and mechanical properties. And chemical properties. Therefore, transparent AION ceramic is the preferred material for missile fairing, infrared window material and bulletproof armor material. To

2. Performance comparison of three commonly used mid-infrared materials. Table 1 shows the performance comparison of three commonly used mid-infrared materials: aluminum oxynitride (AlON), sapphire (sapphire) and spinel (MgAl204). Table 1 Commonly used mid-infrared material performance comparison material AlON sapphire spinel density (g/cm3) 3.7 3.98 3.59 bending strength 300 400 184 hardness (GPa) 185 220 152 optical transmittance (3-5μm) 85% 85% 85 % Dielectric constant 9.3 9.4 9.2 Dielectric loss 0.0022 0.0005 0.0027

3. The advantage of aluminum nitride material The optical performance of AlON transparent ceramic is equivalent to that of sapphire and spinel, and its bending strength is close to that of sapphire and significantly higher than spinel. The processing cost of window materials prepared from sapphire single crystals is very high, and it is difficult to obtain large-size products, while AlON ceramics can achieve the preparation of large-size and complex-shaped products through advanced ceramic preparation methods.

(Aluminum oxynitride: a transparent ceramic that can be bulletproof)