An investigation on electromagnetic shaping and solidification behavior of supperalloys under vacuum environment

The present paper is dealing with the processing of castings and ingots for Fe-, Ti-, and Ni based alloys with shaped cross section by an electromagnetic confined forming technique. This method can realize less contamination, lower segregation and refined structure for ingots because they are formed under the confinement of electromagnetic field instead of currently used physical mold. The solid/liquid interface, the profile behavior of melt and the temperature gradient during electromagnetic confinement are measured and studied. Based on systematically investigation on the distribution behavior of magnetic and temperature field and their coupling effect, and on the dynamic stability of melt, some containerless electromagnetic shaping samples of stainless steel and superalloy were successfully prepared by means of an specially designed vacuum apparatus with dual induction coils and dual frequencies. By using of a tailor-made crystallizer, near-net-shaped superalloy turbine blade castings with directionally solidified microstructure were also obtained with electromagnetic soft-contact technique.