Propulsion and Logistics Systems

Solid propellants with significantly higher density impulse vs conventional aluminumbased propellants can be prepared utilizing zirconium metal fuel. This has beenindependently demonstrated by several investigators including Atlantic Research Corp-oration, a commercial propellant manufacturer. The extreme electrostatic discharge(ESD) sensitivity of zirconium metal has prevented its use in high density impulsepropellants. In a previous SBIR from NSWC, MACH I demonstrated and developed surfacepassivation technologies to dramatically improve the ESD sensitivity of hafnium metalfor use in energetics.In preliminary internal R&D, MACH I has shown this technology to be feasible forzirconium metal, dramatically improving its ESD sensitivity from 0.00025 to a safelevel of 0.036 joules. Since this technology involves forming a surface intermetal-lic with aluminum, there should not be a significant impact on reactivity or densityimpulse. We are proposing a program to optimize the ESD sensitivity improvement,reactivity, and impulse of the zirconium propellants. Atlantic Research Inc. wouldbe a subcontractor to MACH I testing reactivity and other propellant properties. Onepound of the optimum material would be produced in Phase I. In phase II, this wouldbe further developed and propellants commercialized. Zr Energy, a domestic producerof zirconium has committed to supply materials to this program and could quickly com-mercially produce the passivated zirconium should the technology be successfullydeveloped.The proposed program has the potential to greatly improve the safety and handlingcharacteristics of zirconium metal thus making high density impulse zirconium propel-lants a reality. The 15% higher density impulse of these propellants vs conventionalaluminum based propellants gives the system designer the flexibility of eithersmaller lighter rocket motors for a given impulse and pay-load requirement or largerimpulse and payload capabilities for a given motor size.Dual use benefits to the civilian automotive and light truck industries would berealized by improving the safety and handling characteristics of zirconium metal.Zirconium potassium chlorate accidents cause two fatalities in 1998/9 due to ESDrelated problems.