High-pressure rotational deformation apparatus to 15 GPa

A new apparatus has been developed that allows large-strain plastic deforma tion experiments under high pressure with a controlled strain rate in simpl e shear deformation geometry. A modification is made to a Drickamer-type op posed anvil apparatus to allow torsion tests by attaching a rotation actuat or composed of a dc servomotor and a gear box. A thin disk of a sample (les s than similar to0.8 mm thick and to similar to4 mm diameter) can be sheare d between two anvils under pressure by a rotation actuator. Specimens of Fe were sheared to strains exceeding gamma similar to6 at pressures up to sim ilar to 15 GPa. Nearly simple shear deformation was achieved when the initi al sample thickness is less than similar to0.4 mm. This apparatus allows st udies of plastic flow and deformation microstructures under high pressures. (C) 2001 American Institute of Physics.