A portable high-pressure stress cell based on the V7 Paris–Edinburgh apparatus

Abstract

We describe a new device, based on a V7 Paris–Edinburgh press, for torsional testing of material at pressures up to 7 GPa (extendable to 15 GPa). Samples are deformed using a simple shear geometry between opposed anvils by rotating the lower anvil, via a rotational actuator, with respect to an upper, stationary, anvil. Use of conical anvil profiles greatly increases sample dimensions more than other high-pressure torsional apparatus did. Samples of polycrystalline Zr (2 mm thick, 3.5 mm diameter) have been sheared at strains exceeding γ ∼1.5 at constant strain rate and at pressures from 1.8 to 5 GPa, and textural development has been studied by electron microscopy. Use of amorphous-boron-epoxy gaskets means that nearly simple shear of samples can be routinely achieved. This apparatus allows study of the plastic and anelastic behaviour of materials under high pressure, and is particularly suited for performing in situ investigations using synchrotron or neutron radiation.

Keywords:

• high pressure
• deformation
• torsion
• anelastic

Acknowledgements

The authors thank Colin Morrison and Paul Taylor (Dept. Earth Sciences, University of Cambridge), and John Adams (Harmonic Drive UK Ltd.) for help in the design and construction of the roPEC. They also thank Shun-ichiro Karato for helpful discussions regarding the rotational Drickamer apparatus and an informative visit to Yale during the design stage for the roPEC. The manuscript was improved following comments of two anonymous reviewers. This project was supported by NERC grant LBZF/039 (to SAT Redfern and MT Dove).

Additional information

Notes on contributors

Geoffrey D. Bromiley

†Present address: School of GeoSciences, University of Edinburgh, Grant Institute. The King's Buildings, West Main Road, Edinburgh, EH9 3JW, UK.