Metal treatment – Process of modifying or maintaining internal physical... – Magnetic materials
Patent
1990-09-28
1992-02-25
Sheehan, John P.
Metal treatment
Process of modifying or maintaining internal physical...
Magnetic materials
21912117, 21912166, H01F 102
Patent
active
050910213
ABSTRACT:
Nonmagnetized permanent magnet material is heated in a pattern by a laser beam to a localized temperature above the Curie point or a temperature sufficient to reduce the coercivity sufficiently for an external field to magnetize the pattern in the direction of the field. Magnets so produced can have very high pole density, digital encoding and analog patterns having gradually varying local field strength. Alternating pole magnets of this type can be used for stepper motor magnets.
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Bradley John R.
Fuerst Carlton D.
Perry Thomas A.
Schroeder Thaddeus
General Motors Corporation
Grove George A.
Sheehan John P.
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