Orientation, morphology and magnetostriction of a heat-treated 〈1 1 0〉 oriented TbDyFe alloy

〈1 1 0〉 oriented rods of a TbDyFe magnetostrictive alloy have been successfully prepared by zone melting unidirectional solidification. A homogenization annealing for 4h or 48h at 1000°C has been carried out in a quartz cylinder under Ar₂ protection after pumping to 2 × 10^-3Pa. The preferred orientation, morphologies and magnetostriction of the TbDyFe rods with directional solidification or annealing have been investigated. The 〈110〉 preferred orientation remains unchanged after annealing. The net-shaped pseudo-eutectic rare earth phase becomes discontinued and spheroidal after annealing for 4h and shows spheroidal shape without the net-shaped morphology after annealing for 48h. The magnetostriction slightly decreased after annealing without pre-stress, but increased drastically with pre-stress. An obvious magnetostriction jump effect was observed in the annealed samples. A satisfactory magnetostrictive property of 1970 × 10 ^-6 was obtained under 15MPa pre-stress after 4h heat treatment without a further improvement for 48h annealing, which indicates that the heat treatment for 4h at 1000°C is proper for the present 〈1 1 0〉 oriented TbDyFe alloy.