5th International Conference on Advances in Solidification Processes (ICASP-5) 5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining (CSSCR-5)

During solidification of alloys with a temperature gradient in a stati magnetic field, the thermoelectric magnetic(TEM) force may be induced. The TEM force will produce convection in the molten metal and stress in the solid during the solidification. The convection and stress may play an important role in the formation of the micro-and macro-structures of the alloy. The influence of the thermoelectric magnetic force on the unidirectional solidification of Al-Cu alloys under a static magnetic field has been investigated experimentally. It is shown that the TEM force induced the instability of solid/liquid interface, which is the sound verification of the ATG instability model proposed by Asalor, Tiller and Granfield in 1990`s. The experiments showed that the dendrite growth was modified seriously and the dendrite spacing increased along with increase of the magnetic field. The columnar- equiaxed transition during directional solidification of the alloy was promoted by the imposing of a astatic magnetic field, due to the TEM force and convection. The static magnetic field was imposed in the additive manufacturing of superalloy with laser melting. It is shown that the magnetic field accelerated the CET transition and the crystal grains were refined. The result was attributed to the strong TEM force in the process.