Recrystallization Texture and Shear Band Formation in Bending

抄録

The influence of texture on the shear bands and workability in bending was examined by using an age-hardened polycrystalline high concentration of Ni-Si copper alloys with various recrystallization textures. Samples with dominant the Cube orientation of {001}<100>, the RD-rotated Cube orientation of {012}<100>, the BR orientation of {362}<853>, and the R orientation of {231}<346> were employed. The formation of shear bands and the bending workability depended on the texture in the W-shape bending test, in which the bending direction was RD. The sample with a strongly developed Cube orientation showed the best bending workability. In comparison, the samples with the developed BR orientation and random orientation showed poor bending workability. The shape of the cracks generated by bending was linear, and these cracks developed in the shear bands, which were inclined at 35–40° from the surface. To elucidate the mechanism behind shear band formation, inhomogeneous deformations were investigated using the FE-SEM/EBSD method. The dependence on the crystallographic orientations was discussed using the full constraint Taylor model premising both the plane strain compression and the shear strain modes.

Fig. 8 Enlarged image near the crack in Fig. 7 demonstrating the state before the displacement due to shear banding with generation of the crack. The yellow arrow indicates the vector of parallel moving of the cropped area surrounded by yellow dashed line. The ‘x’ indicates grains C, D, and E.