Polycrystalline Alumina Ogive Missile Domes

The increasing missile velocities coupled with higher sensor performance requires commensurate improvements in window and dome performance so that they do not limit the imaging capability of the sensors. Sapphire is the most durable, commercially available infrared missile dome material. The machining and polishing of sapphire into more aerodynamic dome shapes, such as an ogive, is a difficult and expensive endeavor. CeraNova proposes to produce ogive missile domes of its already demonstrated transparent polycrystalline alumina (PCA). Polycrystalline alumina can be cast into difficult shapes. Like sapphire, PCA offers excellent erosion and wear resistance due to its high hardness, combined with good strength and toughness. CeraNova has produced transparent PCA disks that meet or exceed the capabilities of sapphire in demanding applications. The uniform polycrystalline microstructure, increased hardness and toughness, and near-net shape processing of CeraNova PCA present significant advantages in infrared window and dome applications for high speed missiles. In the program proposed here, CeraNova use a powder process to produce near-net shape hemispherical and ogive PCA domes to meet or exceed final polished dimensional tolerances and surface finishes required for missile applications. Preliminary experiments have verified the feasibility of this method producing high density sintered centimeter size samples.