Through the performance of infrared window materials should meet the basic needs of the following:
High mechanical strength: infrared window materials must have high strength, load to decompression during high speed movement;
Good thermal stability: head of infrared window material should be the temperature shock aerodynamic changes and high heating, transmission ratio and refractive index should not change with temperature and remarkable changes;
Chemical stability: head of infrared window material is exposed in the air, should be able to prevent corrosion of salt solution or corrosive gases in the atmosphere, not easy to deliquescence.
High optical transmittance: must be able to effectively transmit ultraviolet to infrared radiation.
Good optical properties, optical scattering and refractive index homogeneity;
To meet the requirements of the large size of the window.
Sapphire single crystal as a kind of excellent filtering material, in the ultraviolet, infrared, visible light has good transmittance, can meet the requirements of multi-mode compound guidance, at the same time, sapphire crystal has high mechanical strength, good chemical stability, good high temperature resistance, high strength, high hardness, can also meet the high supersonic missile the wave-transparent material demands.
In the material preparation, sapphire single crystals can be grown, and then forming, the same properties and crystal properties of the finished products, and other materials by powder hot pressure casting sintering, its performance than the original should be slightly lower, so the sapphire single crystal has become the advanced countries in high-speed aircraft, missiles and other selected excellent wave infrared window material.