High Quality Spinel Powders for Missile Dome Applications

Smart weapons are widely used to improve targeting efficiency, minimize collateral damage and avoid civilian causalities. For optical target recognition and guidance, infrared, and visible frequencies are used, requiring the use of transparent missile domes. The domes must transmit infrared and visible light with high resolution and low signal loss while being exposed to extreme conditions. Sapphire is one of the few materials whose mechanical and optical properties meet operational constraints. Unfortunately, sapphire domes are very expensive because of the excessive shaping needed to produce a dome shape. Spinel has been qualified for domes in several missile systems and can be hot-pressed to near net shape, significantly reducing the grinding needed and thereby greatly reducing cost. Unfortunately, impurities in the starting materials adversely affect the yields and quality of the transparent spinel domes. In the Phase I project TDA developed precursor powders that we used to make a transparent spinel part of high quality. In the Phase II project we will optimize our powders to further improve the quality of the final parts and scale up powder production in order to supply spinel parts makers with the high quality powders they need to make trial and initial production runs.