纵向磁场作用下DZ417G高温合金的枝晶生长行为

Dendrite growth behavior of DZ417G superalloy under longitudinal magnetic field

研究纵向磁场对高温合金DZ417G定向凝固显微组织的影响。结果表明:在较低生长速率下,磁场能显著影响高温合金柱状枝晶的生长;低磁场(<0.1T)能使枝晶生长规则化,生长方向逐渐统一并平行于磁场方向,一次枝晶臂间距减小;高磁场(>2T)破坏枝晶生长,枝晶发生断裂,逐渐出现一些云状组织;随着生长速率的增大,磁场的影响逐渐减弱。并从磁场诱发热电磁对流和熔体流动影响枝晶生长的角度对实验结果进行分析。

The influence of longitudinal magnetic field on the microstructures of DZ417G superalloy at different growing rates was investigated.The results show that the magnetic field（0.1 T） can affect significantly the regular dendrite growth and primary dendrite arm spacing of DZ417G superalloy at low growing rate,and the growth direction is parallel to the direction of magnetic field.But the high magnetic field（2 T）can disturb the regular morphology of dendrite growth.The dendrite morphologies are destroyed when the magnetic field is applied.The effect of magnetic field is weak when the growing rate increases.Based on the theory of the influence of magnetic field on fluid,the above phenomenon was analyzed.