MAGNETIC FIELD HEAT TREATMENT METHOD AND APPARATUS THEREFOR

PROBLEM TO BE SOLVED: To stabilize the magnetic characteristic of a strip state magnetic material used to a magnetostrictive vibrating piece. SOLUTION: Plural pieces of heaters 24 are assembled into the thick part of a cylindrical body 20. A coil 22 is wound on the outer periphery of the cylindrical body 20. One pair of guide rods 28 are arranged in a hollow part of the cylindrical body 20. Many grooves 31 are formed in a plate-like holders 30 and the magnetic material 5 cut as strip-state is incorporated into each groove 31. Guide rods 28 are inserted into one pair of notches 32 formed in the holders 30 and the holders 30 are incorporated in the hollow part of the cylindrical body 20 so to pile up in the thickness direction. The magnetic material 5 is heated by working the heats 24 and the magnetic field is generated along the axial direction of the cylindrical body 20 by working the coil 22. This magnetic field is impressed in the width direction of the magnetic materials, and the magnetic field heat treatment is simultaneously applied to many magnetic material by executing the temp. adjustment of the heaters 24 under this conditions.