Effect of high magnetic field on the primary dendrite arm spacing and segregation of directionally solidified superalloy DZ417G

摘要

High magnetic field has been applied to the directional solidification of superalloy DZ417G. The results show that high magnetic field can significantly influence the primary dendrite arm spacing and microseg-regation. A 6T magnetic field can decrease the primary dendrite arm spacing by 22 percent at a drawing speed of 40 mu m/s. Nevertheless, when the magnetic field is greater than 6T the primary dendrite arm spacing begins to increase. The microsegregation of Ti and Mo can be also decreased by about 28 percent and 40 percent respectively with a 6T magnetic field at a drawing speed of 40 mu m/s. These phenomena are attributed to the competitive relationship of the electromagnetic damping and thermoelectromagnetic convection caused by the high magnetic field.