DYNAMIC RESPONSE OF SINGLE CRYSTALLINE COPPER SUBJECTED TO QUASI-ISENTROPIC, GAS-GUN DRIVEN LOADING

Jarmakani, H ; Mc Naney, J M ; Schneider, M S ; Cao, B Y ; Orlikowski, D ; Nguyen, J H ; Kad, B ; Meyers, M A

Lawrence Livermore National Laboratory

关键词: Copper;    Compression;    75 Condensed Matter Physics, Superconductivity And Superfluidity;    Stacking Faults;    36 Materials Science;   

DOI  :  10.2172/886674
RP-ID  :  UCRL-TR-216902
RP-ID  :  W-7405-ENG-48
RP-ID  :  886674

美国|英语

来源: UNT Digital Library

【 摘 要 】

A transmission electron microscopy study of quasi-isentropic gas-gun loading (peak pressures between 18 GPa and 52 GPa) of [001] monocrystalline copper was carried out. The defect substructures at these different pressures were analyzed. Current experimental evidence suggests a deformation substructure that transitions from slip to twinning, where twinning occurs at the higher pressures ({approx}52 GPa), and heavily dislocated laths and dislocation cells take place at the intermediate and lower pressures. Evidence of stacking faults at the intermediate pressures was also found. Dislocation cell sizes decreased with increasing pressure and increased with distance away from the surface of impact. The results from the quasi-isentropic experiments are compared with that of flyer-plate and laser shock experiments carried out by Cao et al. [1] and Schneider et al. [2], respectively. The Preston-Tonks-Wallace and Zerilli-Armstrong constitutive descriptions are used to model both isentropic and shock compression experiments and predict the pressure at which the slip-twinning transition occurs in both cases. Both models predict a higher transition for isentropic then for shock experiments, and indeed, that twinning should not take place in the ICE experiments at the pressures investigated.