Notch effect on the tensile properties of cold-rolled Ni3Al foils

Notch effect on the tensile properties of the Ni3Al foils has been investigated as a function of notch geometry and foil’s thickness. Tensile tests along the rolling direction (RD) and the transverse direction (TD) showed that notch weakening occurred with introduce of a notch. Plastic deformation was observed locally at notch root and the effective stress concentration factor (ke) was much lower than the theoretical stress concentration factor (Kt). Contrary to the anisotropy in fracture stress along the RD and the TD, ke fell on the same curve. Crack initiation mechanism was different between two tensile directions, that is, cracks initiated along the shear band in the RD tension, while cracks initiated homogenously on the slip planes in the TD tension.