The effect of magnetic field on precipitation phases of single-crystal nickel-base superalloy during directional solidification

• A magnetic field distinctly decreases the size of γ′ phase of Ni-based superalloy.
• A magnetic field distinctly decreases the content of carbides and γ/γ′ eutectic.
• The segregation of alloying elements is decreased by magnetic field.

The effect of magnetic field on precipitation phases in directional solidified single-crystal nickel-base superalloy was investigated. The magnetic field significantly decreases the size of γ′ and the content of carbides and γ/γ′ eutectic. The decreased magnitude is firstly sharp and then gentle with the increasing magnetic field intensity. The γ′ phase refinement could be attributed to a decrease in nucleation activation energy during solid phase transformation. The segregation reduction of alloying elements is responsible for the content decrease of carbides and γ/γ′ eutectic. The magnetic- field-assisted directional solidification provides an effective way to control the size and content of precipitation in superalloys.