Solute segregation behavior of nickel-based single crystal superalloys directionally solidified under transverse static magnetic field

The solute segregation behavior of Ni-based single crystal (SX) superalloys directionally solidified over wide ranges of solidification rates under various intensities of transverse static magnetic field (TSMF, 0–0.7 T) is systematically investigated. The results show that the influence of TSMF on solute segregation depends on magnetic field intensity and solidification rate. At low solidification rate, the applied TSMF during directional solidification can dramatically suppress the solute segregation, which may lead to a narrow range of segregation and lessen γ/γ' eutectic. The partition coefficients of Ti and W with severe segregation tendency all tend to be near one. The measured results of alloy elements concentration in the mushy zone indicate that the thermoelectric magnetic convection (TEMC) induced by TSMF may obviously change the solute distribution in the melt. On the contrary, at high solidification rate, the applied TSMF has little influence on solute segregation, which may be mainly attributed to the low intensity and reduced action time of the magnetic field. The research results may provide a better understanding on interaction between solidification processing and static magnetic field, which is helpful to develop a new method for segregation control on SX superalloys.