INVESTIGATION ON ANISOTROPY OF DYNAMIC COMPRESSIVE MECHANICAL PROPERTIES OF COLD--ROLLED Cu SHEET

The quasi-static and dynamic compressive mechanical properties of cold-rolled and annealed Cu sheets were investigated by means of Instron apparatus and Split-Hopkinson pressure bar (SHPB)technology,respectively.Cylindrical specimens of textured Cu sheets,which were cut with the cylinder axes along the rolling direction(RD),transverse direction(TD)and normal direction(ND), were compressed at strain rates in the range of 10~(-3)to 10~3 s~(-1).The compressive stress-strain curves show all that the flow stresses for both cold rolled and annealed Cu sheets increase with the increase of strain rate and the obvious effect of strain rate hardening has been observed.The quasi-static and dynamic compressive mechanical properties of the cold rolled Cu sheet exhibit pronounced anisotropy, both the yield strength and flow stresses at the low deformation degree for the TD direction are the maximum,while those for the RD direction are the minimum.The properties of annealed Cu sheet are isotropic.Taking into account of possible mechanism for quasi-static and dynamic plastic deformation, the mechanical anisotropy of textured Cu sheets could be explained qualitatively by Taylor model based on the microscopic crystal plasticity theory.