Application of an Infrared Transmitting Dielectric to Concave Spherical Surfaces

The dome for the Joint Common Missile (JCM) program is required to have a patterned metal mesh buried between inner and outer dielectric layers. Surmet has worked closely with the Army and Lockheed Martin to produce prototype domes by bonding inner and outer shells of ALON or Spinel together. The purpose of the proposed effort is to replace the inner dome shell with an inexpensive dielectric layer that is bonded directly to the outer dome shell without intermediate adhesives, resulting in a more affordable ‘Composite’ dome. The dielectric material must be compatible with Magneto-Rheological Finishing (MRF), in order to achieve the very tight wavefront requirements of the JCM program. During the Phase I effort, NRL’s BGG glass and Corning’s 9754 Germanate glass were identified as the most promising candidates. The results of ongoing experiments will determine which of these two glasses will be carried forward into the proposed effort.