Magnetic body formed from encapsulated ferromagnetic particles and method for the manufacture thereof.

摘要

A method for stress-relieving a compression-moulded magnetic body is provided for purposes of enhancing the magnetic permeability of the magnetic body. The method involves encapsulating ferromagnetic particles with a preferred polymeric coating material, comprising either a polybenzimidazole or a polyimide derived from either 3-4' oxydianiline or polymethylene dianiline. The preferred coating materials are capable of withstanding elevated temperatures for a duration which is sufficient to anneal the magnetic body formed from the coated metal particles. As a result, the stresses induced in the magnetic core by the compression-moulding process can be relieved without detriment to the mechanical properties and magnetic characteristics of the magnetic core.