Effect of hydrostatic pressure on the plasticity of copper

A new technique is designed to plot stress-strain curves during torsion at hydrostatic pressure up to 250 MPa. It is used to study the effect of pressure on the torsional strain to failure of copper. The experimental results demonstrate that the plasticity of the material increases in the pressure range 0–150 MPa and remains constant in the range 150–250 MPa. This reaction of the material is likely to be related to the fact that pressure can increase the dislocation density required for plastic flow.