Accelerated Development of Edge Bonded ALON® Reconnaissance (Recce) Windows

Requirements for future reconnaissance (Recce) systems are driving the need for very large (~32x32-in), very high quality windows. At the present, the only window material available in the size and quality demanded by these applications is Cleartran or hot isostatic pressed (HIPped) ZnS. While it is available, this material is relatively weak and very soft. This requires large Cleartran windows to be made in substantial thicknesses (~1-in thick), making them very heavy. Furthermore, these very heavy and expensive windows are extremely susceptible to damage from environmental loading (i.e., rain and sand erosion) in the flight environment. For these reasons, the Air Force has long been interested in stronger, more durable, and lighter alternatives. High quality ALON® windows have been produced in sizes up to 17x30-in in size. The most rapid, and economical means to achieve much larger sizes is through the edge bonding of ALON blanks into larger blanks. During the proposed Phase I effort, the feasibility of such an approach will be demonstrated. BENEFIT: Successful completion of this program will result in availability of high quality, Edge Bonded ALON ® windows for high end reconnaissance applications