Technique of melting and casting of (TbDy)Fe 2 matrix alloy bars

Abstract

The technique of melting and casting rare earth giant magnetostrictive bars was investigated with super high temperature gradient directional solidification equipment developed by the authors. A number of φ7×120-mm bars with a smooth appearance were manufactured successfully; bars with different dimensions can be obtained by changing the molds. The results reveal that the fabrication process is available and simple. Under normal melting, the losses of Tb and Dy can be controlled to within 1 and 3%, respectively. The mean composition errors of the rare earth elements Tb and Dy are less than 1.5%. Metallographic examinations reveal that the microstructure is notably dependent on the mold temperature. In addition, the full process from melting and casting to directional solidification can be performed in the same equipment, and investment in facilities for melting and casting is not required.