Semi-hard magnetic material for a reed switch and process for producing the same
AssigneeFujitsu Limited
InventorsYuichi Suzuki, Masanori Okada, Zenzo Henmi
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Abstract
Due to an Mo addition, to a known Co-Fe-Nb semi-hard magnetic material, the coercive force is enhanced without causing deterioration of the cold workability of the semi-hard magnetic material. In addition, the energy product, the residual flux density and the fullness factor are high according to the semi-hard magnetic material of the present invention. Such material is particularly suited for reed pieces of reed switches, which are mounted in a four wire crosspoint switch.
Claims31
A semi-hard magnetic material comprising a composition in the following ranges
- iron from 12 to 18% by weight,
- niobium from 2 to 4%,
- molybdenum from 2 to 5%,
- cobalt for essentially the balance, and
- said material comprising a coercive force above 35 oersteds.
A process for producing a semi-hard magnetic material comprising a coercive force above 35 oersteds, residual magnetic flux density above 11 kgauss and a fullness factor of not less than approximately 0.80, said process comprising:
- forming a composition comprising iron in the range from 12 to 18% by weight, niobium between 2 and 4% and molybdenum between 2 and 5%, and cobalt in the balance;
- solution treating said material;
- rapid cooling said solution treated material;
- cold working said solution treated material at a reduction of area of at least 90%;
- and
- aging said cold worked material at a temperature in the range from 600.degree. to 750.degree. C.
Dependencies are inferred from the claim text.