Significant recrystallization suppression in a nickel-based single crystal superalloy during solution treatment via alternating magnetic field

Recrystallization during heat treatment deteriorates nickel-based single crystal superalloys. This study demonstrates that alternating magnetic field (AMF) significantly suppresses recrystallization in grit-blasted nickel-based single crystal superalloy DD98M. Under 1300 °C/4 h heat treatment, the recrystallization thickness increased from 28.3 to 71.2 μm with grit-blasting pressure (0.1–0.7 MPa), but AMF (0.05–0.1 T) reduced it by 47.5% and 65.7%, respectively. The effect was attributed to the decrease in dislocation density gradient and residual stress via dislocation depinning induced by AMF. This approach offers a promising strategy for controlling recrystallization in superalloys.