Tb-containing multi-main-phase neodymium iron boron permanent magnet and manufacturing method

Abstract

The invention discloses a Tb-containing multi-main-phase neodymium iron boron permanent magnet and a manufacturing method. The permanent magnet contains a plurality of main phases with different contents of rare earth elements, an oxide phase exists among the main phases, and the oxygen content of the oxide phase is higher than the oxygen content of the main phases; a high Tb-content main phase exists in the plurality of main phases, crystal grains formed by the plurality of main phases are isolated by a grain boundary phase, and the average crystal grain size is 6-14mum; heavy rare earth RH comprises more than one of the Dy, Tb, Ho, Gd and Y elements. The manufacturing method comprises the steps of first alloy smelting, second alloy smelting, third alloy smelting, hydrogen decrepitation, alloy mixing, powdering through a jet mill, magnetic field formation, vacuum sintering, aging and the like; the step of first alloy smelting comprises a process of preparing first alloy containing the Nd element; the step of second alloy smelting comprises a process of preparing second alloy containing the Pr, Nd and Dy elements; the step of third alloy smelting comprises a process of preparing third alloy containing the Pr, Nd and Tb elements.

Description

technical field [0001] The invention belongs to the field of permanent magnet devices, in particular to a Tb-containing multi-main phase NdFeB permanent magnet and a manufacturing method. Background technique [0002] Corrosion-resistant high-performance permanent magnet is a basic electronic component and electrical component widely used in the world today, mainly used in computers, mobile phones, televisions, automobiles, communications, toys, audio, automation equipment, nuclear magnetic resonance imaging, etc. With the requirements of energy saving and low-carbon economy, high-performance permanent magnets have begun to be applied in energy-saving household appliances, hybrid electric vehicles, wind power generation and other fields. [0003] U.S. Patent No. 7,258,751 authorized on August 21, 2007 and U.S. Patent No. 7,867,343 authorized on January 11, 2011 disclose heat treatment of quick-setting alloy sheets at 400-800°C for 5 minutes to 12 hours. Make the RH element ...

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Problems solved by technology

[0003] U.S. Patent No. 7,258,751 authorized on August 21, 2007 and U.S. Patent No. 7,867,343 authorized on January 11, 2011 disclose heat treatment of quick-setting alloy sheets at 400-800°C for 5 minutes to 12 hours. Make the RH element move from the grain boundary phase to the main phase, thereby increasing the coercive force of the rare earth magnet; US Patent No. 7,585,378 authorized on October 8, 2009 discloses a method for manufacturing an alloy for R-T-Q series rare earth magnets. It consists in rapidly cooling the alloy melt to a range of 700-1000°C to form a quick-setting alloy, and then keeping the quick-setting alloy at a temperature of 700-900°C for 15-600 seconds; State-bed airflow milling powder technology, using cyclone collector to collect powder; the disadvantage of fluidized bed is that the bottom material of tens of kg is always kept in the mill, and the powder-making speed is controlled by controlling the weight of the bottom material, which affects the powder-making Particle size, carry large particles, need to take out the bottom material when changing the brand, the bottom material is easy to oxidize; the disadvantage of the cyclone collector is that the fine powder with a particle size of less than 1 μm will be discharged with the exhaust airflow, affecting the product yield and particle size distribution

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