Superplastic properties of Inconel 718

The superplastic tensile test of Inconel 718 was carried out using cylinder-like specimens, the flow stress, the strain rate and the value of m under different strain rates and different deformation temperature being examined. Excellent elongation (467%) and high flow stress (41.3 MPa) were gained in the superplastic tensile test of Inconel 718 refined by pre-treatment, i.e., at a temperature of 1000 °C and strain rate of 1.14×10−4 s−1. At the same time, Inconel 718 showed good superplasticity when the strain rate and deformation temperature were changed in the range 10−4 to 10−1 s−1 and 940–1020 °C, respectively. Additionally, the superplastic properties were explained through observation of the microstructure.