NdFeB sintered magnet production method and production device, and NdFeB sintered magnet produced with said production method

Abstract

Provided is a method and system for producing a slim-shaped sintered NdFeB magnet having a high level of coercive force and high degree of orientation, as well as a sintered NdFeB magnet produced by the aforementioned method or system. A system for producing a slim-shaped sintered NdFeB magnet according to the present invention includes: a filling unit 1 for supplying and filling alloy powder with a predetermined content of Dy into a mold 10 at a density within a range from 3.0 to 4.2 g / cm 3 ; an orienting unit 3 for subjecting the molds 10 holding the alloy powder 11 to an orienting process in a magnetic field; a sintering furnace (not shown) for sintering the alloy powder 11 together with the molds 10 holding the alloy powder 11 after the powder is oriented by the orienting unit 3; and a conveying unit, consisting of a belt conveyer and a manipulator (not shown), for conveying the molds 10 to any of the aforementioned units or the sintering furnace. The orienting unit 3 is provided with a heating and orienting coil 20 for heating the alloy powder 11 in the molds 10 before and / or after the application of the magnetic field so as to decrease the coercive force of the individual particles of the alloy powder 11.

Description

Technical field [0001] The present invention relates to a manufacturing method and manufacturing apparatus for manufacturing a thin-shaped NdFeB-based sintered magnet having excellent magnetic properties, particularly coercivity and orientation, and the NdFeB-based sintered magnet manufactured by the manufacturing method. Background technique [0002] The NdFeB (neodymium·iron·boron) series sintered magnet was discovered by Sagawa (the inventor of the present application) and others in 1982. It has the advantage of having magnetic characteristics far exceeding that of the permanent magnets at the time, and it can be made of Nd (A kind of rare earths), iron and boron are relatively abundant and inexpensive raw materials. Therefore, NdFeB-based sintered magnets are used in voice coil motors such as hard disks, hybrid or electric vehicles driving motors, battery-assisted bicycle motors, industrial motors, high-end speakers, headsets, permanent magnet magnetic resonance diagnosis In...

AI Technical Summary

Problems solved by technology

However, the chips generated in the cutting process cannot be reused as magnets, which reduces the utilization efficiency of materials and increases the production cost.

In addition, the mechanical damage caused by cutting makes the squareness of the demagnetization curve (H K / H CJ ) and other problems of magnetic property degradation also exist

Images