Development and Testing of Advanced EM Accelerator Bore Materials
Abstract
Electromagnetic railguns are being considered for a number of potential Strategic Defense, Theater Missile Defense and tactical missile applications. Bore materials, particularly insulators, limit the performance and lifetime of current railguns. A program was undertaken to develop improved advanced ceramic insulators. The program aim was to: analytically determine the property goals required of bore insulators to meet railgun systems requirements; select and design initial candidate materials using micro-architectural tailoring; fabricate and test panels of the selected materials; iterate compositions and processing parameters to improve properties; and down-select to an optimal material and scale it up to a size required for near-term railguns. From the start of the program it was realized that ceramics alone possessed the necessary properties to meet the system requirements. Through a combination of mechanical and electrical tests a large number of ceramic materials were screened. Microstructurally toughened aluminum oxide based ceramics gave the best combination of mechanical and electrical properties. The addition of chromia to the base alumina-zirconia-yttria composition improved the electrical properties with no compromise in mechanical properties. The alumina-chromia material was successfully scaled up to 1.5 x 4 x 18 inch pieces, representative of large railgun bore insulators. These scaled up pieces also met the mechanical and electrical goal Properties for railgun insulator operation. The additional work required to produce and qualify these insulator materials for reliable and cost effective high-energy railgun utilization was recommended. Railguns, Electromagnetic, Aluminum oxide, Ceramics, launcher, Fracture toughness, Insulators, Bore materials, Hot pressing.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1992
- Accession Number
- ADA247467
Entities
People
- John W. Mccoy
- R. D. Stevenson
- Stuart N. Rosenwasser