Sintered NdFeB powder orienting method

Abstract

The invention relates to the field of machining of magnetic materials and in particular relates to a sintered NdFeB powder orienting method which comprises the following steps: a. putting the blank NdFeB powder into a mold cavity; b. leading poles at two sides of a press into vibration or alternating current to form a vibration magnetic field; c. press-fitting a mold; and d. after press fit is completed, applying a current reverse to the smaller current on poles at two sides for carrying out demagnetization, thus obtaining a bloom. The poles at two sides of the press are circularly and alternatively fed into vibration or alternating current to form the vibration magnetic filed; the NdFeB powder dithers in the mold cavity so as to remove the clustering phenomenon of the NdFeB powder to a great extent, thus improving the orientation level and achieving better consistency for all magnetism of the bloom; and during the dithering process, the filling compactness of the powder in the mold cavity is more uniform, the initial pressing intensity after compression is more uniform, the sintered bloom has better form and position tolerance, the grinding amount of the bloom can be decreased, and the cost is lowered.

Description

Technical field [0001] The invention relates to the field of ferromagnetic material processing, in particular to an orientation method of sintered neodymium iron boron powder. Background technique [0002] Sintered neodymium iron boron is an anisotropic magnet, and the alloy powder needs to be oriented in a magnetic field to form an oriented structure, so that the magnet has high magnetic properties. When the neodymium iron boron blank powder is formed orientated, the powder is put into the mold cavity, and the poles on both sides begin to be energized to generate a magnetic field. The powder is arranged in a regular manner under the action of the magnetic field. At this time, the upper and lower pressure heads of the mold begin to oppose pressure. The poles on both sides apply a reverse magnetic field with a smaller current to demagnetize the magnetized blank. At present, the orientation method of sintered NdFeB powder is mostly one-time orientation, that is, the pole current i...

AI Technical Summary

Problems solved by technology

At present, the orientation method of sintered NdFeB powder is mostly one-time orientation, that is, the current of the pole head is directly added from zero ampere to the current saturation point, and it rises in a straight line. Complete, that is, if the arrangement position is wrong, the consistency of the magnetic properties of the sintered NdFeB blank is reduced, and the density of the blank is not uniform

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