Assessment of anisotropic tensile strength using a modified shear punch test for Cu–Cr–Zr alloy processed by severe plastic deformation

Abstract

The effect of severe plastic deformation on the anisotropic strength change was investigated by equal-channel angular pressing (ECAP) experiments with various pass numbers. To overcome the size limitation for the tensile test specimen, this study proposes a shear punch test modified by using a flat-end rectangular punch to evaluate uniaxial tensile strength in multiple directions in the longitudinal and transverse sections of the ECAP-processed Cu–Cr–Zr alloy. The validity of the modified method was verified by the linear relationship between the shear punch test data and tensile test data in the longitudinal direction. Specimens were prepared at three angles (0°, 45° and 90°) with respect to the extrusion direction in the longitudinal sections and the horizontal direction in the transverse sections of the ECAP bar. The results showed that tensile strength deceased when the angle increased from 0° to 90° in both the longitudinal and transverse sections. The longitudinal sections showed a more pronounced anisotropy than the transverse sections. As the amount of plastic deformation by ECAP increased, the degree of the anisotropy decreased in the longitudinal section but increased in the transverse section. Based on the results of this study, the strength of an ECAP material must be assessed in multiple directions in both the longitudinal and transverse sections.