Environmentally Insensitive Active Decluttering

The Phase I program demonstrated molybdenum-rhenium (Mo-Re) alloys exhibited negligible erosion and wear in terms of weight loss, which was nearly 100 times less than chromium plated gun steel in vented bomb test at 40,000 lbs/in2 using EX-99 propellant.Laser fusion fabrication was utilized and a short 155mm barrel section, including rifling, was formed that contained Mo-Re functionally graded into titanium and shrink-fitted into a 4340 outer steel barrel. The Phase II program will optimize the Mo-Reratio versus vented bomb erosion and wear, followed by mechanical property characterization including fatigue life. Barrel sections with Mo-Re functionally-graded into the barrel structure will be formed and live fire tested. Additional optimization willprovide barrels for further live fire and fatigue life testing to provide a basis for producing production barrels that substantially eliminate erosion and wear with advanced propellants as well as fatigue life as a design limitation