Manufacturing process of sintered NdFeB permanent magnet for magnetic lifter

Abstract

The invention relates to the field of sintered NdFeB permanent magnet materials, in particular to a sintered NdFeB permanent magnet manufacturing process for a magnetic jack so that the permanent magnet coercive force is controlled to be 12.0 KOe to 12.5 KOe by the existing production process can be solved. The manufacturing process comprises the following steps that: step one, a sintered blank with the coercive force between 8.0 KOe and 10.0 KOe is made; step two, the NdFeB sintered blank is ground and processed and then surface polishing, cleaning, and drying are carried out on the sinteredblank to obtain a semi-finished product with a smooth, clean and dry surface; step three, on the basis of physical vapor deposition, one yttrium-antimony alloy layer is deposited on the surface of theNdFeB semi-finished product, wherein the yttrium-antimony alloy deposit amount is controlled by reaching the 0.1% of the weight of the semi-finished product and increasing the coercive force by 0.6KOe; and step four, eutectic heat treatment is carried out on a NdFeB workpiece coated with the yttrium-antimony alloy film in vacuum furnace equipment, so that a finished product with the coercive force in a range of from 12.0KOe to 12.5KOe is obtained.

Description

[0001] The invention relates to the field of sintered NdFeB permanent magnet materials, in particular to a manufacturing process of sintered NdFeB permanent magnets for magnetic lifters. Background technique [0002] Sintered NdFeB permanent magnet has high remanence, high magnetic energy product and high coercive force, known as the "magnet king". Human beings use the magnetic field to magnetize macroscopic substances, and use NdFeB permanent magnets in magnetic lifters, which can skillfully achieve the purpose of lifting, supporting, and transporting materials. Therefore, NdFeB permanent magnets are used in magnetic lifters has been widely used. [0003] In the magnetic lifter, the remanence and magnetic energy product of the NdFeB permanent magnet determine the magnetization lifting capacity, and although the coercive force does not directly determine the magnetization lifting capacity, it has a very important meaning: on the one hand, if the permanent The low coercive for...

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Problems solved by technology

[0003] In the magnetic lifter, the remanence and magnetic energy product of the NdFeB permanent magnet determine the magnetization lifting capacity, and although the coercive force does not directly determine the magnetization lifting capacity, it has a very important meaning: on the one hand, if the permanent The low coercive force of the magnet will lead to a decrease in the anti-demagnetization ability of the permanent magnet, especially when used in some high-temperature environments, it is easier to accelerate the demagnetization of the permanent magnet, which will lead to danger, so NdFeB permanent magnets are required On the other hand, if the coercive force is high, when multiple permanent magnets are assembled in the magnetic lifter, a large demagnetization field will be formed between the magnets, resulting in lifting The device has a large residual magnetism and cannot be separated from the lifted material smoothly

[0004] Based on the above situation, it has been verified by practice that the coercive force of the NdFeB permanent magnet used by the magnetic lifter is expected to be controlled within the range of 12.0KOe to 12.5KOe, so that is the deviation between the lowest value and the highest value. Control at 0.5KOe; however, when the current NdFeB permanent magnet manufacturing process is in production, in the same batch of magnets, if the fluctuation value of the coercive force is properly controlled, the deviation between the lowest value and the highest value is generally 1.0KOe Above, therefore, the NdFeB permanent magnets currently used for magnetic lifters either require the sorting performance of NdFeB manufacturers, or require the magnetic lifter manufacturers to select and combine multiple times during assembly, or they are making NdFeB magnets. The coercive force needed to ensure that there is no loss of magnetism is the priority when assembling directly, and the magnetic lifter manufacturer tolerates the residual magnetism of some devices. These methods are insufficient for the use of magnetic lifters.

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