Metal treatment – Process of modifying or maintaining internal physical... – Magnetic materials
Patent
1994-11-25
1996-02-20
Sheehan, John
Metal treatment
Process of modifying or maintaining internal physical...
Magnetic materials
148101, 296021, 21912117, 21912166, H01F 104
Patent
active
054925720
ABSTRACT:
A magnetized or unmagnetized body of a permanent magnet material is heated in a pattern by a laser beam to a temperature sufficient to lower the coercivity of selected heated regions of the pattern and exposed to a magnetic field to magnetize or to remagnetize the selected heated regions. A pattern guide is used in the process to densify the pattern. In the process, energy is directed through the pattern guide and onto the selected regions, while the pattern guide prevents or minimizes heating of unselected portions of the body. Magnets so produced can have very high pole density, digital encoding and analog patterns having gradually varying local field strength.
REFERENCES:
patent: 4312684 (1982-01-01), Chraplyvy et al.
patent: 4347086 (1982-08-01), Chraplyvy et al.
patent: 5089060 (1992-02-01), Bradley et al.
patent: 5091021 (1992-02-01), Perry et al.
Ara et al, "Formation of Magnetic Grating on Steel Plates by Electron/Laser Beam Irradation", IEEE Transactions on Magnetics, vol. 25, No. 5, Sep. 1989, pp. 3830-3832.
Bradley et al, "Microstructure and Magnetic Properties of Co.sub.2 Laser Surface Melted Nd-Fe-B Magnets", Journal of Magnetism and Magnetic Materials, vol. 86 (Apr., 1990) pp. 44-50.
Croat et al, "Crystallization of Amorphous Pr.sub.0.27 Co.sub.0.73 : Magnetic Properties and Laser-Induced Coercivity", Appl. Phys. Lett., vol. 37, No. 10, 15 Nov. 1980, pp. 962-964.
Gambino (editor), "Optical Storage Disk Technology", MRS Bulletin, vol. XV, No. 4, Apr. 1990, pp. 20-22.
Greidanus et al, "Magneto-Optical Storage Materials", MRS Bulletin, vol. XV, No. 4, Apr. 1990, pp. 31-39.
Hansen, "Magneto-Optical Recording Materials and Technologies", Journal of Magnetism and Magnetic Materials, vol. 83 Jan. 1990, pp. 6-12.
Herbst et al, "Laser Annealing and Selective Magnetization of Manganese-Aluminum Alloys", Appl. Phys. Lett., vol. 37, No. 8, 15 Oct. 1980, pp. 753-754.
Kryder, "Advanced in Magneto-Optic Recording Technology", Journal of Magnetism and Magnetic Materials, vol. 83 Jan. 1990, pp. 1-5.
Lunney et al, "Enhanced Corrosion Resistance Fe.sub.40 Ni.sub.38 Mo.sub.4 B.sub.18 and Nd.sub.15 Fe.sub.77 B.sub.8 by Laser Glazing", SPIE, vol. 1023 Excimer Lasers and Applications (1988), pp. 216-223.
Weller-Brophy et al, "Materials Challenges in Integrated Optical Recording Heads", MRS Bulletin, vol. XV, No. 4, Apr. 1990, pp. 25-30.
Bradley John R.
Lequesne Bruno P. B.
Perry Thomas A.
Schroeder Thaddeus
General Motors Corporation
Grove George A.
Sheehan John
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