| 摘要 |
PROBLEM TO BE SOLVED: To obtain a magnetic material having excellent magnetic characteristics and mechanical strength by coating the surfaces of rare earth metal powder, needle-shaped iron powder and boron powder with coating material, mixing them at a prescribed mixing rate and sintering a molded body formed in the magnetic field in an inert atmosphere furnace. SOLUTION: Material powders of a rare earth metal, needle-shaped iron and boron whereupon coating layer is formed are mixed and are molded in the magnetic field. Then, the molded body is sintered for a prescribed time in an argon atmosphere at a prescribed temperature, the needle-shaped iron powder is oriented vertical to the magnetic field while being sintered, the rare earth metal and boron are diffused in the needle-shaped iron powder and a rare earth metal-iron-boron alloy layer is formed on the surface of the needle- shaped iron powder. Oxidation of each metal is prevented by the coating layers, and the energy product and the mechanical strength of the magnetic body can be improved by preventing the grain diameter of each powder from being easily increased. |
