The objective of the proposal is to reduce the cost of fabrication of sapphire optical hyper-hemispheres for submarine masts. Due to the nature of sapphire, deriving complex geometries from grown boules using current conventional fabrication techniques is one of the major contributors to cost. Removing excess material requires long diamond grinding cycles. New advances in ultrasonics have been incorporated by machine tool manufacturers to couple this technology with conventional diamond grinding techniques in order to accomplish orders of magnitude increases in stock removal with no impact on surface finish and sub-surface damage.
Benefit: The successful reduction of grinding times for sapphire will result in lower fabrication costs for hyper-hemispheres that result in lower procurement costs for the Navy. The technology will also permeate into other programs that utilize complex sapphire components and similarly will drive down those costs. It is anticipated that the benefits to the fabrication of sapphire will be applicable to other tough materials such as the many varieties of toughened ceramics.
Keywords: Closed-Loop Probe Metrology, Closed-Loop Probe Metrology, Sapphire, Grinding Time Reduction, Hyper-Hemispherical Window, Ultrasonic Assisted grinding, Enhanced Stock Removal
