High Strength Spinel Sensor Windows

Spinel is a transparent polycrystalline ceramic whose combination of high hardness, light weight and broad band transmission (UV-Mid IR) properties make it ideal for transparent armor and reconnaissance pods and combined RF/laser communication windows. This Phase II SBIR program details a comprehensive approach to enhance the ballistic properties of Spinel by doubling its strength and minimizing the two primary contributors to the large scale manufacturing cost of Spinel armor: spinel powder and grinding and polishing costs. By improving the inherent strength of spinel new, lighter weight armor solutions can be developed for ground vehicles and aircraft. Based on encouraging Phase I results, the strength of spinel can be almost doubled utilizing glass or spinel coatings or by adjusting spinel's stoichiometric ratio. The goal is to successfully apply these strengthening techniques to large area spinel windows. The two remaining areas, spinel powder production and low cost grinding and polishing efforts build off previous small scale successes as well. Success in these areas promises to help overcome the first two of three hurdles that still confront the insertion and associated benefits of transparent spinel armor: 1)procurement costs, 2)strength optimization for ultimate ballistic performance and 3)large scale production capabilities.