Hot Deformation Behavior and Microstructure of Cast Ni-Based Superalloy IN-100 Based on the Processing Map

Hot compression tests were performed on a cast Ni-based superalloy IN-100 at various temperatures and strain rate ranges. From the flow stress-true strain curves and the microstructure observations, a processing map of the hot deformation was constructed based on the dynamic material model. At 1473 K, flow stresses showed a plateau region resembling the characteristics of a dynamic recovery, although values varied with the strain rate. The crystal orientation rotated from the initial <001> direction parallel to the compression axis to the <101> direction, which is the primary slip direction of the fcc system. Kink band formation was observed perpendicular to the compression axis, and fine discontinuous dynamic recrystallization at the boundary of the kink bands was observed for the slow strain rate. As the strain rate increased, meta-dynamic recrystallization was observed after the compression test. At 1373 K, the flow stress first increased sharply and then decreased gradually with increasing strain over the whole strain rate. Twin deformation was suggested to occur prior to the appearance of dynamic recrystallization under 1373 K for the low strain rate range. The stable region of hot deformation was considered to be located at approximately 1423 K and 0.003 s(-1).

Automated summary

Hot compression tests were conducted on a cast Ni-based superalloy IN-100 to investigate its hot deformation behavior. A processing map of the hot deformation was constructed based on the flow stress-true strain curves and microstructure observations. The results show that the flow stress and crystal orientation of the alloy vary with different temperatures and strain rates, and various types of recrystallization phenomena were observed.