The formation mechanism of stacking faults in ZrFe2 Laves phase in Zircaloy-4 alloy

The role of grain boundary (GB) migration in producing stacking faults (SFs) in nanosized C15 structured ZrFe2 Laves phase precipitate was studied by transmission electron microscopy (TEM). Results revealed that the interaction between the studied second phase particle (SPP) and the GB was occured, which result in the curvature change of GB near the SPP. The movement of GB was hindered by the SPP which changed the normal migration of GB to that leaving behind a large number of faulted stacking in the SPP. In addition, the SPP was embedded in the α-Zr grain matrix; therefore, a dragging force of GB was applied on the SPP. Further deformation engendered the stacking faults in the centre of SPP by virtue of the maximum dragging force on the GB.