The deformation and the recrystallization initiation in the dendrite core and interdendritic regions of a directionally solidified nickel-based superalloy

The deformation and the recrystallization initiation in the dendrite core and interdendritic regions were investigated by employing microhardness tester, optical microscope, scanning electron microscope and electron backscatter diffraction technique. It was found that different recrystallization nucleation mechanisms operated in the dendrite core and interdendritic regions. Recrystallization nucleation may take place by strain induced boundary migration in the dendrite cores, while particle stimulated nucleation occurs in the interdendritic regions. The deformation and the recrystallization initiation in the dendrite core and interdendritic regions were compared and discussed. The role of the carbides and eutectics in particle stimulated nucleation was also clarified.