The effect of temperature and microstructure on dynamic deformation of iron, tantalum, and titanium

Journal Article · Wed Sep 23 00:00:00 EDT 2015 · Journal of Applied Physics

OSTI ID:1808244

Chen, L. E. ^[1]; Swift, D. C. ^[2]; Florando, J. N. ^[2]; Hawreliak, J. ^[2]; Lazicki, A. ^[2]; Austin, R. A. ^[2]; Saculla, M. D. ^[2]; Eakins, D. ^[1]; Bernier, J. V. ^[2]; Kumar, M. ^[2]

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1. Imperial College, London (United Kingdom)
2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Laser-driven shock loading was performed on thin samples of iron, tantalum, and titanium at strain-rates up to 10⁷ s^–1, and over a range of temperatures extending from 120 through 800 K, to investigate the influence of temperature on the early stages of yielding and plastic flow in materials of distinct crystal structure and initial defect density. The onset of yielding was identified using time-resolved velocimetry of the target rear surface to reveal the peak elastic state in the precursor wave front. Measurements on as-received iron reveal a trend of decreasing peak elastic stress (σE) with increasing temperature and electron microscopy of the recovered material revealed evidence of mobile dislocations coalescing into subgrains. This is in contrast to the results for the annealed iron where theσEremains constant with increasing temperature and recovered samples showed indications of deformation twinning. For tantalum, the yield strength remains constant for the most part, but has a jump in yield strength at 815 K, indicative of a possible twinning to slip transition with increasing temperature. For titanium, the yield strength was generally constant with temperature. Here, these results provide insight into studying deformation mechanisms, such as slip and twinning, in high rate loading of materials.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-07NA27344
• OSTI ID: 1808244
• Report Number(s): LLNL-JRNL-679035; 800968
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics; ISSN 0021-8979
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE