Method for preparing high-performance R-Fe-B system sintering magnetic body

Abstract

The invention relates to a method for preparing a high-performance R-Fe-B system sintering magnetic body. According to the method for preparing the high-performance R-Fe-B system sintering magnetic body, due to the fact that heavy rare earth powder R<2> or R<2>X is added to powder composed of R<1>-Fe-B-M alloy, the purpose of enrichment of a heavy rare earth element on grain boundaries is achieved, after forming of the powder is accomplished in a pressed mode, pressure is exerted on the powder to enable the powder to reach a preset density through a pressure sintering device in a state with a temperature smaller than a normal sintering temperature, and the added heavy rare earth elements is made to scatter on the areas of the grain boundaries. The method for preparing the high-performance R-Fe-B system sintering magnetic body has the advantages that due to the fact that the heavy rare earth element of a small amount is added, coercive force of the magnetic body is obviously improved under the premise that reduction of remanence is small, production efficiency is high, and the method for preparing the high-performance R-Fe-B system sintering body is not limited by the size of the magnetic body.

Description

technical field

[0001] The invention relates to a method for preparing a high-performance R-Fe-B series sintered magnet, which belongs to the field of rare earth permanent magnet materials. Background technique

[0002] Nd-Fe-B magnets are widely used due to their superior performance, especially due to the demand for energy-saving motors in automotive and electronic applications, the market application of sintered NdFeB will be further expanded. The improvement of remanence and coercivity of NdFeB materials is conducive to its rapid growth in the motor market, but the improvement of coercivity in traditional processes is always at the expense of remanence, and a larger proportion must be used to increase coercivity The heavy rare earth element Dy / Tb causes a sharp increase in the cost of the magnet. In order to reduce the amount of heavy rare earths such as Dy / Tb and achieve high temperature resistance, the recently developed low-dysprosium high-coercivity magnets mainly u...

Examples

Embodiment 1

[0031]Under the protection of argon gas, vacuum melting furnace is used to melt the arranged raw materials to form R with a thickness of 0.1-0.5mm. 1 -Fe-B-M alloy flakes, the main components of the flakes include: 5.69wt% of Pr, 18.22wt% of Nd, 6.18wt% of Dy, 0.98wt% of B, 1.51wt% of Co, 0.1wt% of Ga, 0.29wt% % Al, the total content of R1 is 30.09wt%. After the R1-Fe-B-M alloy flakes are subjected to HD and jet milling, the particle size of the jet milling powder obtained is SMD=3.3μm. Add heavy rare earth powder R 2 It is Dy powder, and the average particle size of Dy powder is 0.9 μm. Take 10 kg of R1-Fe-B-M jet mill powder and mix it with the above-mentioned 0.1 kg of Dy powder, then mix for 3 hours, then add 0.15wt% lubricant to continue mixing for 3 hours, and then use 15KOe magnetic field orientation compression molding after mixing. Made into a green compact with a compact density of 3.95g / cm 3 .

[0032] The compact is sent to a pressure sintering device for vacu...

Embodiment 2

[0036] Use a vacuum melting furnace to melt the configured raw materials under the protection of vacuum or inert gas to form scales with a thickness of 0.1-0.5mm, and the obtained R 1 -Fe-B-M alloy scales have clear metallographic and grain boundaries, and the main components of the scales include: 4.72wt% Pr, 25.67wt% Nd, 0.52wt% Dy, 0.97wt% B, 0.9wt% Co, 0.1wt% Ga , 0.1wt% Al, its R 1 The total content is 30.91wt%. . R 1 - The Fe-B-M alloy scales are mechanically pulverized, and the diameter of the scales is less than 2 mm, and then ball milled to an average particle size of 6 μm. Add heavy rare earth powder R 2 It is Tb powder, 0.4wt% of heavy rare earth powder is added to the total weight, and the average particle size of heavy rare earth powder is 1.8 μm. above R 1 - After mixing Fe-B-M powder and heavy rare earth powder, continue ball milling for 360 minutes to fully mix the two powders. After the mixing is completed, the magnetic field orientation of 15KOe is use...

Embodiment 3

[0040] Use a vacuum melting furnace to melt the prepared raw materials under the protection of vacuum or inert gas to form scales with a thickness of 0.1-0.5mm. The main components of the scales include: 4.72wt% of Pr, 25.67wt% of Nd, 0.52wt% of Dy, 0.97wt% of B, 0.9wt% of Co, 0.1wt% of Ga, 0.1wt% of Al, its R 1 The total content is 30.91wt%. R 1 - After the Fe-B-M alloy flakes are subjected to HD and jet milling, the resulting jet milling particle size SMD=3.2μm. Add heavy rare earth R 2 or R 2 X is Dy powder and Dy 2 o 3 Powder mix, Dy powder with Dy 2 o 3 The average particle size of the powder mixture is 0.9 μm, and its main components include: 93.55wt% Dy and 6.45wt% O. The added heavy rare earth powder accounted for 1.6wt% of the total weight. After the above powders are mixed, first mix for 3 hours, then add 0.15wt% lubricant and continue to mix for 3 hours. After the mixing is completed, use a magnetic field orientation of 15KOe to make a green compact with a ...

technical field

[0001] The invention relates to a method for preparing a high-performance R-Fe-B series sintered magnet, which belongs to the field of rare earth permanent magnet materials. Background technique

[0002] Nd-Fe-B magnets are widely used due to their superior performance, especially due to the demand for energy-saving motors in automotive and electronic applications, the market application of sintered NdFeB will be further expanded. The improvement of remanence and coercivity of NdFeB materials is conducive to its rapid growth in the motor market, but the improvement of coercivity in traditional processes is always at the expense of remanence, and a larger proportion must be used to increase coercivity The heavy rare earth element Dy / Tb causes a sharp increase in the cost of the magnet. In order to reduce the amount of heavy rare earths such as Dy / Tb and achieve high temperature resistance, the recently developed low-dysprosium high-coercivity magnets mainly u...

Examples

Embodiment 1

[0031]Under the protection of argon gas, vacuum melting furnace is used to melt the arranged raw materials to form R with a thickness of 0.1-0.5mm. 1 -Fe-B-M alloy flakes, the main components of the flakes include: 5.69wt% of Pr, 18.22wt% of Nd, 6.18wt% of Dy, 0.98wt% of B, 1.51wt% of Co, 0.1wt% of Ga, 0.29wt% % Al, the total content of R1 is 30.09wt%. After the R1-Fe-B-M alloy flakes are subjected to HD and jet milling, the particle size of the jet milling powder obtained is SMD=3.3μm. Add heavy rare earth powder R 2 It is Dy powder, and the average particle size of Dy powder is 0.9 μm. Take 10 kg of R1-Fe-B-M jet mill powder and mix it with the above-mentioned 0.1 kg of Dy powder, then mix for 3 hours, then add 0.15wt% lubricant to continue mixing for 3 hours, and then use 15KOe magnetic field orientation compression molding after mixing. Made into a green compact with a compact density of 3.95g / cm 3 .

[0032] The compact is sent to a pressure sintering device for vacu...

Embodiment 2

[0036] Use a vacuum melting furnace to melt the configured raw materials under the protection of vacuum or inert gas to form scales with a thickness of 0.1-0.5mm, and the obtained R 1 -Fe-B-M alloy scales have clear metallographic and grain boundaries, and the main components of the scales include: 4.72wt% Pr, 25.67wt% Nd, 0.52wt% Dy, 0.97wt% B, 0.9wt% Co, 0.1wt% Ga , 0.1wt% Al, its R 1 The total content is 30.91wt%. . R 1 - The Fe-B-M alloy scales are mechanically pulverized, and the diameter of the scales is less than 2 mm, and then ball milled to an average particle size of 6 μm. Add heavy rare earth powder R 2 It is Tb powder, 0.4wt% of heavy rare earth powder is added to the total weight, and the average particle size of heavy rare earth powder is 1.8 μm. above R 1 - After mixing Fe-B-M powder and heavy rare earth powder, continue ball milling for 360 minutes to fully mix the two powders. After the mixing is completed, the magnetic field orientation of 15KOe is use...

Embodiment 3

[0040] Use a vacuum melting furnace to melt the prepared raw materials under the protection of vacuum or inert gas to form scales with a thickness of 0.1-0.5mm. The main components of the scales include: 4.72wt% of Pr, 25.67wt% of Nd, 0.52wt% of Dy, 0.97wt% of B, 0.9wt% of Co, 0.1wt% of Ga, 0.1wt% of Al, its R 1 The total content is 30.91wt%. R 1 - After the Fe-B-M alloy flakes are subjected to HD and jet milling, the resulting jet milling particle size SMD=3.2μm. Add heavy rare earth R 2 or R 2 X is Dy powder and Dy 2 o 3 Powder mix, Dy powder with Dy 2 o 3 The average particle size of the powder mixture is 0.9 μm, and its main components include: 93.55wt% Dy and 6.45wt% O. The added heavy rare earth powder accounted for 1.6wt% of the total weight. After the above powders are mixed, first mix for 3 hours, then add 0.15wt% lubricant and continue to mix for 3 hours. After the mixing is completed, use a magnetic field orientation of 15KOe to make a green compact with a ...

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