Fine Grained Conformal Spinel Blanks

Surmet will produce prototype, conformal spinel window blanks under the proposed Phase II effort. The particular geometry selection will be made in consultation with a Major Defense contractor who is developing conformal optics for real world applications, and be reviewed with our Navy COTRs. The conformal window will be at least 16x 16 in size and have a sag of at least 6. One potential geometry under consideration for the spinel conformal window, is the leading edge of an aircraft wing. During Phase II, Surmet will establish the processes and tooling required to: 1) select and define a particular conformal window shape for the effort, 2) form a spinel green blank, and 3) fully heat treat these conformal spinel green blanks to full optical density. Two full sized conformal window blanks will be produced. Coupons will be cut from large blanks and characterized with respect to, transmission, haze and clarity as well as strength. During the Phase II Option effort, Surmet will inspection polish one of these conformal blanks to a sufficient degree to allow inspection of the material for internal cracks and inclusions, and striae. However, the level of polish achieved will not be sufficient for transmitted wavefront measurements.