Preparation method of high-Hk samarium-cobalt sintered permanent magnet material

Abstract

The invention discloses a preparation method of a high-Hk samarium-cobalt sintered permanent magnet material. The method comprises the following steps of: proportioning, smelting of an alloy ingot, pulverizing, drying, orienting to prepare a blank, sintering for solid solution, pre-tempering and tempering, putting of a magnet in an ultrahigh-pressure environment for ultrahigh-pressure pre-tempering, and graded tempering or slow cooling tempering treatment. The preparation method of the high-Hk samarium-cobalt sintered permanent magnet material adopts the ultrahigh-pressure pre-tempering treatment and then graded tempering or slow cooling tempering treatment to obviously increase the formation rate of a fine Cu-rich region, these regions become a formation center of the Cu-rich 1:5H cell wall pinning phase during the tempering, and the size of the cellular microstructure is reduce so that the volume fraction of the Cu-rich 1:5H cell wall pinning phase is increased, the knee point coercive force Hk of the prepared samarium-cobalt sintered permanent magnet material is increased by 30%-35% on the premise that the residual magnetism Br, the maximum magnetic energy product (BH)max and the intrinsic coercive force Hcj are kept unchanged, and the knee point coercive force Hk is greatly increased.

Description

technical field [0001] The invention relates to the field of rare earth permanent magnet materials, in particular to a high H k A preparation method of samarium cobalt sintered permanent magnet material. Background technique [0002] SmCo sintered permanent magnet has developed into an indispensable important metal in aerospace, electrical engineering, magnetic machinery, microwave communication, instrumentation and other fields due to its irreplaceable advantages of low remanence reversible temperature coefficient, corrosion resistance and high temperature resistance. One of the functional materials. It is characterized by high coercivity, high Curie temperature, and good corrosion resistance. Therefore, compared with NdFeB, SmCo sintered permanent magnet materials can work stably for a long time in high temperature and humid environments, and are very suitable for manufacturing various magnets. A high-performance permanent magnet motor and an application product with a v...

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Problems solved by technology

At present, the 30H grade magnet prepared by the manufacturer of samarium cobalt sintered permanent magnet has a knee point coercive force of H k ≈18kOe, which cannot meet the market's growing demand for high knee coercive force H k needs

[0004] In the preparation of existing samarium-cobalt permanent magnets, such as the invention patent CN104637642B discloses a samarium-cobalt sintered permanent magnet material and its preparation method. The samarium-cobalt sintered magnets prepared by this method have the same and uniform grain size, which improves the sintered permanent magnet. Various properties, including the knee point coercive force H k , however, the tempering process used in this method is a commonly used tempering process in the industry, so it cannot achieve high H k Preparation of SmCo Sintered Permanent Magnets

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