Tensile deformation behavior of copper bicrystal with perpendicular grain boundary

The tensile deformation behavior of a copper bicrystal with a perpendicular grain boundary was investigated using digital image correlation (DIC) method, and the whole field deformation distribution on the specimen surface during the tensile test was obtained. The results show that the specimen is deformed in the "double necking" shape. The strain distribution on specimen surface is inhomogeneous, and strain level at the grain boundary is lower than that in the interior of grains. The specimens fracture within the grain with soft orientation. The in-situ tension by scanning electron microscopy (SEM) indicates that slip bands cannot pass through the grain boundary. The above results suggest that the tensile deformation behavior of the copper bicrystal is determined by the orientation of each grain and the property of grain boundary. The grain with soft orientation tends to deform plastically and fracture first. Large-angle grain boundary can impede slip bands and hence strengthen the material.