Program Manager: Ms. Sharon Beermann-Curtin
The Nano-Composite Optical Ceramic (NCOC) Program will use new nano-composite materials with improved mechanical and optical properties to develop infrared windows with increased performance over existing materials in the 3-5 µ regime. Additionally, innovative processing and shape forming techniques will bring revolutionary operational capabilities at a reduced cost.
Infrared seekers used for the guidance of high-velocity missiles require protective domes or windows made from materials that exhibit a combination of good optical properties, such as high transmittance at useful wavelengths, and excellent mechanical and thermal properties, including high strength (at operational temperatures) and thermal shock resistance. Polycrystalline materials with nano-sized grains can leverage the optical and mechanical properties of its constituent phases to increase the mid-wave infrared range of usable wavelengths from 4 µ to
5 µ at elevated temperatures (500−1000 °C) where the current material of choice, sapphire, fails. Additionally, a ceramic (polycrystalline) dome with large dimensions and/or aerodynamic shape can be fabricated to near net shape, eliminating some of the costly grinding. Moreover, the aerodynamic shape reduces the thermal load on the dome and mitigates the effects of particle impact.
Key objectives of this program include developing a material and processes to make infrared windows and aerodynamically shaped domes with optical and mechanical capabilities that exceed those of single crystal sapphire for midwave infrared (3-5 µ) operation. Phase I goals are to achieve midwave infrared optical transmission comparable to that of spinel with mechanical properties comparable to those of sapphire. Phase II goals are to decrease optical scatter and to increase mechanical and thermal shock capabilities to exceed those of sapphire. Phase I deliverables will be polished disks. Phase II deliverables will be polished disks, polished hemispheric domes, and polished aerodynamically shaped domes.
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