Advanced, Reinforced-NZP Composites for Ballistic Missile Components & Structures

The next generation of ballistic missiles will require materials which are light-weight and have high-temperature resistance to withstand heating caused by the extreme velocity and harsh environments. In general, ceramic materials satisfy the above requirements for missile applications. More specifically, ceramic matrix composites (CMCs) comprising matrices and fibers which have good thermo-mechanical and dielectric properties are extremely attractive for use as radomes, propulsion / control system components, and thermal protection structures. Candidate matrix materials for such CMCs can be derived from a new class of crystalline ceramics viz. NZPs (sodium zirconium phosphate ceramics) which have low thermal conductivity, excellent thermal shock resistance, strength retention to high temperatures (1400,aC), and melt temperatures > 1800,aC. They typically also exhibit low density and low thermal expansion, which enables ¡low thermal-stress¡" design of structural components. Unfortunately, the mechanical properties of such NZP materials are not adequate to meet the current designs of missiles, and advanced aerospace components. SMAHT Ceramics Inc., therefore, proposes to develop an innovative SiC fiber-reinforced NZP composite technology that combines highly desirable materials attributes such as low density, low thermal expansion, excellent thermal shock resistance, high toughness, high temperature creep resistance and high melt temperature with low cost composite processing.