Research on forming limit of Ni-based superalloy during spinning under complex strain path

Ni-based superalloy components with complex shape, such as conical-cylindrical parts, are one of the most important structural components widely used in aviation and aerospace fields. Composite spinning process, consisting of shear spinning and deep drawing spinning, is the most effective method to manufacture this complex component. However, the fracture and wrinkling defects usually occur due to the severe work hardening and complex strain path. Therefore, in order to evaluate the forming limit of Ni-based superalloy during spinning under complex strain path at room temperature, the finite element model of the shear-deep drawing composite spinning was established. The strain path during the shear-deep drawing composite spinning was analysed. The forming limit of Ni-based superalloy was also studied. Then the forming limit diagram of Ni-based superalloy during the shear-deep drawing composite spinning was established. The results show that the limit half cone angle of Ni-based superalloy for shear spinning is 30°; and the limit deep drawing spinning coefficient is 0.63. The strain path can be approximately the superposition of two linear strain paths during shear-deep drawing composite spinning. The safety zone is “wing shaped” in tension-compression strain zone during the shear-deep drawing composite spinning. The experimental results show that the limit diagram can accurately predict the forming defects.