<110> and <112> oriented growth of Tb-Dy-Fe giant magnetostrictive alloy

The directionally solidified Tb-Dy-Fe magnetostrictive alloys with <110> orientation were prepared in a velocity range from 30 to 720 mm/h, and the solidified morphologies change from planar, cellular to dendritic with increasing growth velocity. An obvious magnetostriction jump effect was observed in the sample with high growth velocity (≥120 mm/h). Two kinds of twin growth mode, single-{lll} and two-{lll}-twin system were observed. The measured magnetostrictions of the samples are basically consistent with the calculated values by the above two twin growth mechanisms. As a comparison, the magnetostriction of <112> oriented crystals prepared with v = 900 mm/h is corresponding to the <110> oriented crystals prepared with high growth velocities.