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Objective, Dome Material/Fabrication: Mid-wave material Extreme environmental durability Technology available to ‘form’ into a monolithic hyper-hemispherical configuration Accurate and repeatable High-speed optical fabrication process Cost effective combination of materials and processing.
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Objective, Dome Material/Fabrication: • Mid-wave material • Extreme environmental durability • Technology available to ‘form’ into a monolithic hyper-hemispherical configuration • Accurate and repeatable High-speed optical fabrication process • Cost effective combination of materials and processing
Material Option(s) review: • Spinel. • Silicon • ALON
Foreign Object Damage, testing: • Testing on ALON, Silicon and Fused Silica. • Being performed at UDRI • Simulate aircraft foreign object damage from take-off/landing (20 m/s to 75 m/s) • Testing being conducted by launching 3/8” diameter granite projectiles into the window samples using a .50 caliber bore compressed-gas gun. • Parts rigidly mounted at 450 AOI • A laser photodetector system has been employed to measure the projectile impact velocity • All parts are being photographed before and after test
Strength of Material, Improvement, ALON • The objective of the ALON strength enhancement program were to increase the strength of ALON so that high thermal shock resistant domes could be made. • Several years of fabrication/thermal processing development yielded a significant increase to the ultimate strength of ALON
Strength of Material, Improvement, ALON Successful Thermal Shock-testing of Domes + much higher ultimate strength exhibited by equi-biaxial flexure testing of plano samples validates the modified material process’