In-situ neutron diffraction study of TWIP in a Ni based superalloy

Twinning induced plasticity (TWIP) has been studied extensively regarding low stacking fault energy (SFE) materials such as steels where the specific deformation mechanism enhances both strength and ductility. In Ni-based alloys, activation of twinning is difficult due to their high SFE. Our recent work revealed that outstanding mechanical properties can be obtained in a Ni-based superalloy by inducing the TWIP effect at a low deformation temperature. Ab initio calculations indicates that SFE is not the controlling effect. To investigate the underlying mechanisms further an in-situ neutron diffraction investigation is proposed. Lattice strain changes and grain rotations with deformation at RT and 77 K derived from the experiment will be correlated to microstructural studies by laboratory techniques to explore the mechanisms and conditions for activating TWIP in high SFE alloys.