Low-Cost AlON Materials for IR Window Applications

Infrared weapon and sensor systems often operate in extremely harsh environments. This places stringent requirements on the mechanical and thermal shock properties of the IR window material. Currently, sapphire appears to be the material of choice formany IR window applications. Nevertheless, there are certain disadvantages of sapphire. First, the costs of fabricating, polishing and finishing sapphire are very high. Second, due to its anisotropic structure, sapphire must be produced in singlecrystal form to satisfy all the requirements for IR windows. Apparently, an alternative lower cost material for IR windows is needed. In this Phase I research, Nanomat, Inc. will demonstrate that transparent AlON components can be manufactured costeffectively and can replace sapphire for IR window applications. The consolidation of AlON powder will be carried out to obtain transparent AlON compacts. The optical properties, mechanical properties, thermal shock property and durability of the AlONcompacts will be evaluated. AlON materials have a wide variety of commercial and defense applications, including IR windows, missile domes, scanner window, metal vapor lamp envelopes, high temperature windows and transparent armor systems. Due to itschemical stability at high temperatures, AlON can also be used as refractories in metallurgical and materials industries.