Selection and evaluation of insulator materials for high performance railgun bores

Both conductor and insulator materials used in railgun bores are major factors in achieving the desired system performance parameters and barrel lifetime. This paper reports the interim results of a systematic effort to review the design requirements, and to select, evaluate, and test candidate insulator materials with the potential to best meet these requirements. Approximately fifteen (15) commercial and advanced insulator materials including organic polymers, reinforced polymers, reinforced glasses, technical ceramics, advanced ceramics and reinforced ceramics are included. Pertinent performance parameters based on material properties are compared to the results of small railgun screening tests. The arc exposures were performed at the U.S. Army Ballistic Research Laboratory. The extent and modes of damage, as determined by detailed pre- and post-test evaluation of the arc-exposed insulator materials, are reported.