Measurements of Anisotropy by the Ring Compression Test

In the case of plastic deformation of metals, especially in sheet-metal forming, anisotropy plays a significant role and it is unwise to ignore its effects when selecting a material or while undertaking a theoretical formulation. Conventionally the anisotropic parameters are determined by carrying out tensile tests in orthogonal directions. However, if the information is required for narrow rolled strips or extruded rods, it becomes almost impossible to prepare a standard tensile-test specimen in the transverse direction. Moreover, any tensile test is limited by the onset of necking. A novel adaptation of the ring-compression test to determine the extent of anisotropy is described. The method is established theoretically and the experimental results are compared with those obtained from tensile tests performed on mild-steel specimens of varied rolling reduction. The correlation is reasonably good and with further development the technique using ring compression is expected to establish itself as a powerful tool for studying anisotropy. Some other merits of the technique are also discussed. 8 ref.--AA