List of publications

Physics of the Earth and Planetary Interiors, 145, pp 239-251, (2004) [doi: 10.1016/j.pepi.2004.04.001]

Deformation of polycrystalline iron up to 30 GPa and 1000 K

S. Merkel, H.R. Wenk, P. Gillet, H.K. Mao and R.J. Hemley

Angle-dispersive radial x-ray diffraction measurements were conducted on a- and e-Fe under nonhydrostatic stress conditions up to 30 GPa and 1000 K in laser heated diamond anvil cells. e-Fe (bcc) is found to develop preferred orientation compatible with observations under ambient conditions. The preferred orientation of the a phase is inherited by the e phase (hcp) in accordance with the Burgers orientation relationship, consistent with a martensitic nature of the phase transition. A comparison between the observed texture in e-Fe with results from polycrystal plasticity modeling suggests that the predominant deformation mechanisms are basal slip (0001)<1210> and prismatic slip {1010} <1210>, presumably associated with minor mechanical twinning. We do not observe any evidence of slip on the {1121} <1123> system that was proposed based on analogies with Cr-Ni alloys. Finally, we do not observe any change in preferred orientation upon heating in situ at 28 GPa and 1000 K.

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