110 AND 112 ORIENTED GROWTH OF Tb-Dy-Fe GIANT MAGNETOSTRICTIVE ALLOY
《110》和《112》取向Tb-Dy-Fe超磁致伸缩合金的定向生长

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--{111} and two--{111}--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.