中红外光学材料的高温性能研究

红外光学材料是红外技术应用的基础之一。适用于3~5μm波段的中波红外光学材料正向高性能、大尺寸、低成本等方面发展,具有广阔的应用前景。介绍了尖晶石陶瓷、蓝宝石晶体和氟化镁多晶等中红外光学材料的基本性质,开展了制备技术、光学性能、力学性能和热学性能的研究,比较了温度对发射率、抗弯强度和热导率的影响。结果表明:尖晶石陶瓷具备较高的发射率;氟化镁多晶抗弯强度较差;蓝宝石晶体综合性能较佳,适用于制备基于高温应用的弧形光学器件。

Optical, mechanical and thermal properties of mid-IR materials under high temperature

Infrared optical materials as the base of infrared technology are developing in the direction of larger size and more competitive physicochemical properties.Mid-IR optical materials with positive optical,thermal and mechanical performance are favorable for the civil and military applications.The effect of temperature on emissivity,bending strength and thermal conductivity were investigated in the typical mid-IR materials such as MgAl2O4 spinel ceramics,sapphire crystal and MgF2 polycrystalline.The results show that MgF2 polycrystalline is with smallest emissivity while the thermal conductivity is also the lowest which going against high temperature operation.The bending strength in sapphire crystal is twice higher than those in MgAl2O4 spinel ceramics and MgF2 polycrystalline from 300 ℃ to 500 ℃.Further investigation on the effect of temperature on thermal conductivity indicates that sapphire crystal maintains high thermal conductivity as the temperature is raised.With the achievement of large sized sapphire crystal boule by assembly-line techniques,sapphire crystal is becoming the favorable host for high-temperature optical devices.