Reactive Metals International, Inc. (RMII), a fully owned subsidiary of Mach Ⅰ Inc. has designed,built and tested a Pneumatic Impact Testing Apparatus (PITA) for qualitative and quantitative analysis ofthe impact ignition threshold energies for consolidated reactive materials. The PITA has proven to be anessential tool for routine, cost effective impact testing of reactive materials. The PITA can launch a spherical(0.375” diameter) steel projectile at energies ranging from 10 Joules to greater than 450 Joules correspondingwith projectile velocities of 100 fps to greater than sound speed. A calibration curve of projectile velocity vs.Launch gas pressure has been generated and is utilized in determining impact energies. Ignition is detectedthrough a Si photodetector and overpressure from the ignition event is measured using a piezoresistivepressure transducer. Both detectors are mounted to the wall of a catch box in close proximity to the sample,which is mounted against a steel target plate. The ignition threshold energy was demonstrated for severalcompositions including a thermite type material, a metal-metal intermetallic and a metal-metalloid. Sampleswere prepared by high energy ball milling and consolidated into 0.250” pellets using a hydraulic press. Theeffectiveness of the PITA is exemplified by its accuracy, high throughput and low cost for the routineevaluation of impact- ignition sensitivities/energies for reactive materials. Typically, ignition thresholdenergies for reactive materials can be determined with a sensitivity of a few Joules. The time necessary toproduce the ignition data for a material can be done in a single day using 20-30 rounds.
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