A new multi-anvil press employing six independently acting 8 MN hydraulic rams

Abstract

A new large volume multi-anvil system which employs six independently acting hydraulic rams with independent oil pressurization systems has been developed for high pressure and temperature experiments. The six 8 MN hydraulic rams approach at right angles inside a composite steel plate frame and can each advance a square faceted anvil of either hardened steel or tungsten carbide. The position of each anvil can be measured relative to the frame of the press to a precision of 0.1 μ m. The press is designed to perform both deformation experiments using cubic ceramic pressure media and experiments employing eight inner cubic anvils to compress an octahedral pressure medium. During compression, the position of each anvil relative to the press frame can be precisely measured and controlled independently, thus ensuring a high level of symmetry in the compressive stress environment. The highly cubic compressive regime provides an optimal environment for the use of inner sintered diamond cubic anvils, which can potentially obtain pressures above 50 GPa. The large loading capacity (24 MN) allows larger cubic pressure media to be used at higher pressures than conventional systems.

Keywords:

• a six-axis multi-anvil apparatus
• pressure generation
• deformation

Acknowledgements

The development and construction of six-ram multi-anvil presses for the Bayerisches Geoinstitut and the neutron diffraction beam-line at FRM-II, Garching, Germany has been funded by grants to H. Keppler from the Deutsche Forschungsgemeinschaft (DFG: INST 91/204) and Bundesministerium für Bildung und Forschung (BMBF Projekt 05K10WC2). We are grateful to Kurt Klasinski, Sven Linhardt, Heinz Fischer Stefan Übelhack and the firm of Max Voggenreiter Gmbh, Mainleus, Germany for technical support.