Influence of temperature on the high-strain-rate mechanical behavior of PBX 9501

摘要

High-strain-rate (2000/s) compression measurements utilizing a specially-designed Split-Hopkinson-Pressure Bar have been obtained as a function of temperature from -55 to +50 deg C for the plastic-bonded explosive PBX 9501. The PBX 9501 high-strain-rate data was found to exhibit similarities to other energetic, propellant, and polymer-composite materials as a function of strain rate and temperature. The high-rate response of the energetic was found to exhibit increased ultimate compressive fracture strength and elastic loading modulus with decreasing temperature. PBX 9501 exhibited nearly invariant fracture strains of approximately 1.5 percent as a function of temperature at high-strain rate. The maximum compressive strength of PBX 9501 was measured to increase from approximately 55 MPa at 50 deg C to 150 MPa at -55 deg C. Scanning electron microscopic observations of the fracture mode of PBX 9501 deformed at high-strain revealed transgranular cleavage fracture of the HMX crystals.