The 4th International Conference on Matter and Radiation at Extremes (ICMRE 2019)

430 / 2019-03-01 15:42:55

Dynamic material properties of tantalum under 30-160 GPa ramp compression on PTS facility

quasi-isentropic; strain rate; load stress path control; strength

Plenary track > High Pressure Physics and Materials Science

Metal strength research under extreme conditions is an important application for high energy density physics and aeromechanics. Material’s response has an affinity with microstructure, load path, pressure and temperature, etc. Magnetically driven isentropic compression as a new experimental technique between quasi-static and impact, has low increased entropy and temperature. The Primary Test Stand (PTS) facility is a pulsed power machine capable of delivering currents to loads of 5~8 MA over times of 200-750 ns. Series of ramp compression experiments of tantalum were performed on PTS facility.The loading pressure of the sample exceeded 150 GPa, and the loading strain rate ranged from 10^4 s^-1 to 10^7 s^-1 (average strain rate 10^5-6 s^-1). The strength characteristic data of different process tantalum samples at peak pressure of 29-161 GPa and average loading strain rate of 4-9×10^5 s^-1 under quasi-isentropic loading were successfully carried out, and the isentropic compressive strength characteristics of the annealed/cold-roll regularity knowledge. Experiment results confirmed that the strength of the metal tantalum at 10^5-6 s^-1 strain rate basically conforms to the SG strength model.