Magnetic field modling device, die and method for magnetic field molding
AssigneeTDK Corporation
InventorsNorihisa Saito, Tomohiro Masuda
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Abstract
The objects of the present invention are to provide a durable magnetic field molding device for producing molded bodies for ferrite magnets, which needs a controlled amount of releasing agent, reduces production cost and improves productivity, and die and magnetic field molding method. The lower die 12B of the die 12 is coated, on the surface which defines the cavity 11, with the coating film 30 with a high hardness and a low friction coefficient, which improves resistance of the lower die 12B surface to wear by the solid component (fine powder) in the slurry, thereby greatly improving durability of the coating film 30 itself and reducing lubricant usage.
Claims15
A magnetic field molding device for producing ferrite magnets, comprising:
- a die for compression molding of a slurry of a powder mainly composed of ferrite dispersed in a dispersion medium to form a molded body of a given shape, and
- a magnetic field generating source for applying a magnetic field of a given orientation to the slurry in the die,
- wherein a die cavity surface is coated, at least partly, with a coating film of a material harder than the powder and lower in friction coefficient than a die base material.
A die for producing ferrite magnets, in which a slurry of a powder mainly composed of ferrite dispersed in a dispersion medium is compression-molded to form a molded body of a given shape, comprising:
- a mortar-shaped die provided with a hole(s) having a cross-section of a given shape,
- a lower die fit into the mortar-shaped die hole from beneath, and
- an upper die provided to face the mortar-shaped die,
- wherein the lower die is coated, on the upper side, with a coating film of a material at least twice as hard as the powder and having a lower friction coefficient than a lower die base material.
A magnetic field molding method comprising the steps of:
- injecting a slurry of a powder mainly composed of ferrite dispersed in a dispersion medium into a die coated, at least partly, with a coating film of a material harder than the powder and lower in friction coefficient than a die base material,
- compressing the slurry in the die, while applying a magnetic field of a given orientation to the slurry, and
- opening the die to withdraw the resulting molded body, produced by compression-molding of the slurry, from the die.
Dependencies are inferred from the claim text.