Method for manufacturing alloy rod having giant magnetostriction

摘要

A method for manufacturing an alloy rod having giant magnetostriction, which comprises the steps of: supplying a rod-shaped alloy material, comprising at least two rare earth metals including terbium and dysprosium and at least one transition metal, into a crucible moving downwardly at a speed of from 0.2 to 8.5 mm/minute in an inert gas atmosphere kept under a pressure of from 0.2 to 10 atm.; heating the rod- shaped alloy material in the circumferential direction thereof in the crucible by means of an annular high-frequency heating coil having a frequency of from 0.1 to 3 MHz and having an inside diameter of from 1.1 to 1.6 times as large as an outside diameter of the crucible, arranged so as to surround the crucible; continuously moving the heating from the lower end toward the upper end of the alloy material to locally and sequentially melt the alloy material in the axial direction thereof; and then locally and sequentially solidifying the resultant molten section of the alloy material in the crucible, thereby manufacturing an alloy rod having giant magnetostriction comprising a single-crystal structure or a unidirectional-solidification structure consistent with the axial line thereof.