Fabrication of molded magnetic article
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsRobert G. Bryant, Min Namkung, Russell A. Wincheski, Robert L. Fox
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Abstract
A molded magnetic article and fabrication method are provided. Particles of ferromagnetic material embedded in a polymer binder are molded under heat and pressure into a geometric shape. Each particle is an oblate spheroid having a radius-to-thickness aspect ratio approximately in the range of 15-30. Each oblate spheroid has flattened poles that are substantially in perpendicular alignment to a direction of the molding pressure throughout the geometric shape.
Claims13
A method of fabricating a molded magnetic article, comprising the steps of:
- providing a mold, said mold defining a geometric shape;
- filling said mold with particles of ferromagnetic material and a polymer binder, each of said particles being an oblate spheroid having flattened poles and an aspect ratio approximately in the range of 15-30;
- heating said particles of ferromagnetic material and said polymer binder to a temperature that causes said polymer binder to flow;
- and
- applying pressure to said particles of ferromagnetic material and said polymer binder in said mold, wherein a molded magnetic article is formed in said geometric shape and wherein said flattened poles of said particles are substantially in perpendicular alignment to a direction of said pressure throughout said geometric shape.
A method of fabricating a soft-magnet transformer core to have a desired axis of magnetization, comprising the steps of:
- providing a mold, said mold defining a shape of said transformer core;
- filling said mold with particles of ferromagnetic material coated with a polymer binder, each of said particles being an oblate spheroid having flattened poles and an aspect ratio approximately in the range of 15-30;
- heating said particles coated with said polymer binder in said mold to a temperature that causes said polymer binder to flow;
- and
- applying pressure to said mold along a direction of application that is perpendicular to said desired axis of magnetization, wherein said particles are arranged with said flattened poles thereof substantially parallel throughout said shape and substantially perpendicular to said direction of application.
Dependencies are inferred from the claim text.