<110>取向Tb—Dy—Fe—Co合金棒的磁致伸缩均匀性

HOMOGENEITY OF MAGNETOSTRICTION OF Tb-Dy-Fe-Co <110> ORIENTED ALLOY ROD

采用区熔定向凝固方法,先以30mm/h低速生长,再以480mm/h高速生长,制备了磁致伸缩性能较为均匀的〈110〉取向Tb_(0．36)Dy_(0．64)(Fe_(1-x)Co_x)_2(x=0,0．1,0．15)合金棒．研究了不同晶体生长阶段的轴向择优取向和微观组织对磁致伸缩性能的影响．结果表明,轴向择优取向度主要影响样品在无预压应力条件下的磁致伸缩性能;富稀土相分布主要影响样品在施加预压应力条件下的磁致伸缩性能．沿合金棒轴向,从底部到顶部择优取向度逐渐增高,富稀土相由网状分布变为平行排列,造成合金棒顶部和中部的磁致伸缩性能较底部更高．磁化场为240kA/m时磁致伸缩不均匀度小于6%,显示了良好的均匀性．

〈110〉 oriented Tb0.36Dy0.64（Fe1-xCox）2（x=0, 0.1, 0.15） rods with homogeneous magnetstriction have been prepared by zone melting directional solidification method. The preferred orientations and magnetostrictions of different sections of the rods have been investigated by XRD and standard strain gauge at room temperature, respectively. It was found that the magnetostriction is sensitive to both the crystal orientation and the distribution of the pseudo-eutectic rare earth phase. In comparison with the bottom section of the rods with net-like pseudo-eutectic rare earth phase, higher magnetostriction is always obtained from the middle and top sections with parallel-arranged rare earth phase. The inhomogeneity of magnetostriction under magnetic field of 240 kA/m is less than 6%, indicating better homogeneity.