| 摘要 |
PURPOSE:To improve the manufacture of a magnetic scale and to improve its performance by removing an oxide layer formedthinly on the surface of a magnetic disk when a heat treatment is performed in a magnetic anisotropic treatment and an aging process. CONSTITUTION:A columnar permanent magnetic material is formed by casting. This magnetic material is heated and liquefied, and further heated while applied with a magnetic field lengthwise to perform the magnetic anisotropic treatment. Then, the columnar magnetic material is cooled in a furnace as it is and the aging process is carried out. This magnetic material is cut in round slices by discharge work, etc., to manufacture many disks. In this case, the thin oxide layer nearly in black is formed on the surface in the magnetic anisotropic treatment and aging process, so a grindstone for fine polishing is used to polish it away. Then, a vertical magnetic scale is magnetized by a magnetic head for magnetization on the disk having the surface oxide layer removed.
|
