Deformation mechanism characteristics in a Ni-based alloy X-750: Dislocation/precipitate interaction

Highlights: • The deformation mechanism has planar slip characteristic rather than wavy slip evidenced by planar slip bands. • Gamma-prime precipitate is sheared by dislocations which promotes the planarity of slip in deformation. • Precipitates shearing occur through an anti-phase boundary mechanism and stacking fault mechanism. Transmission electron microcopy (TEM) analysis was employed to characterize the deformation mechanisms in X-750 Ni-based superalloy. Both in-situ and ex-situ tensile tests were carried out at room temperature to observe the dislocation structure and trace the interaction between the γ'-precipitates and dislocations. The deformation mechanism was found to be planar slip which resulted in the formation of planar slip bands. This was attributed to the low stacking fault energy of X-750 alloy as well as the shearing of a high density of ordered γ'-precipitates. The shearing of γ'-precipitates occurred through an Anti-phase boundary (APB) mechanism evidenced by paired superlattice dislocations or a Stacking Fault (SF) mechanism by partial dislocations evidenced by isolated stacking faults within the γ'-precipitates.