Solidification characteristics of Tb0.27Dy0.73Fex (x = 1.8, 1.95) alloys during the directional solidification

Solidification characteristic of intermetallic compound is complex and dependent on its composition and the solidification conditions. Tb0.27Dy0.73Fex (x = 1.8, 1.95) alloy, as an intermetallic compound, exhibits different solidification behavior during its directional solidification. Experimental investigations of the behavior were carried in a super high temperature gradient directional solidification equipment developed by authors. The relationships between the solidification behavior and the solidification condition of Tb0.27Dy0.73Fex (x = 1.8, 1.95) alloys were determined. For Tb0.27Dy0.73Fe1.8 alloy, solidification characteristics with short cylindrical, plate-like and mixed structure were exhibited under the different solidification conditions and zone with a plate-like structure is enlarged with the increase of the temperature gradient and the crystal growth velocity. For Tb0.27Dy0.73Fe1.95 alloy, however, Terfenol-D crystal always grows with a plate-like structure in the experimental ranges. Plate-like structure zone is also enlarged with the increase of the crystal growth velocity and the temperature gradient. The experiment results are helpful for preparing an appropriate Terfenol-D crystal.