Highly corrosion resistant R-Fe-B magnet and preparation method thereof

A corrosion-resistant, magnet technology, applied in the direction of magnetic objects, inductors/transformers/magnet manufacturing, magnetic materials, etc., can solve the problems of great difficulty and risk, and not completely solve the problems of magnet anti-corrosion defects, so as to achieve the effect of improving anti-corrosion ability

Inactive Publication Date: 2009-12-30
EARTH PANDA ADVANCE MAGNETIC MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the anti-corrosion defect of the magnet has not been completely solved, which still has great difficulties and risks for sintered R-Fe-B permanent magnets to enter the motor industry, especially in the field of high-end large motors

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] The 45M magnet is made by ordinary powder metallurgy sintering method:

[0026] 1: Use the formula of Nd23%Pr7%Dy1%B1.0%CO0.5%Cu0.1%Al0.2%Fe67.2% (mass percentage) to melt in a vacuum melting furnace into a steel ingot with a thickness of less than 25mm;

[0027] 2: Use a secondary crusher to break into particles smaller than 20 mesh;

[0028] 3: Finely pulverize into 3-5um powder with jet mill;

[0029] 4: Pressed into a cylindrical magnet of D14*30;

[0030] 5: Sinter in a vacuum sintering furnace at 1080-1105°C for 1-3 hours, and age at 920° for 1-2 hours;

[0031] 6: Grind the outer circle and slice it into a D14*1.5 magnet;

[0032] 7: All magnets are chamfered, pre-treated by pickling, and the magnets aged at 530°C are directly plated with NI-CU-NI;

[0033] 8: The magnet is treated in 90wt% Zn-10wt% Al M alloy at a constant temperature of 530 ° for 3 hours, and then the magnet is taken out of the M alloy and placed in a cooling box with an inert gas and gas-q...

Embodiment 2

[0035]The magnet is treated in a metal alloy of 90wt% Zn-10wt% Al at a constant temperature of 530°C and a pressure of 100mpa for 1 hour, and then the magnet is taken out of the metal alloy and placed in a cooling box with an inert gas. Cool, and then do electroplating NI-CU-NI treatment.

[0036] All the other steps are the same as in Example 1.

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PUM

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Abstract

The invention relates to a highly corrosion resistant R-Fe-B magnet and a preparation method thereof. Surface of the magnet body is covered with fusible and corrosion resistant non-magnetic metal alloy with thickness equal to or more than 2 mum and penetration depth equal to or more than 2 mum into the body. The preparation method comprises the following steps: smelting steel ingot; crushing the steel ingot into particles; crushing the particles into powder; profiling into a cylindrical magnet; melting the alloy metal at ambient temperature of 550 DEG C and fully stirring; putting the cylindrical magnet in melt metal alloy solution during sintering for penetration of the metal alloy solution for 3h; removing the magnet from the metal alloy solution and putting the magnet in an enclosed inert gas air-cooled cooling box for gas quenching, and naturally cooling; sintering in a vacuum sintering furnace; and grinding an excircle and slicing. The magnet has strong corrosion resistance, magnet corrosion by residual liquor at air holes and needle holes is greatly reduced, and hidden trouble of inability to electroplate areas at the air holes and the needle holes by surface treatment process such as electroplating is maximally avoided.

Description

technical field [0001] The invention relates to a highly corrosion-resistant rare earth permanent magnet material and a preparation method thereof. Background technique [0002] High corrosion-resistant rare earth permanent magnet materials can make the magnets used in extremely harsh environments, and can even be used directly without surface plating. In recent years, as rare earth permanent magnet materials have gradually entered the application fields of wind turbines, special motors, and automotive motors, the requirements for high corrosion resistance have also been increasing. Because the boundary phase of the sintered R-Fe-B magnet is an active rare-earth-rich phase, and the main phase (R 2 Fe 14 B) The electronegativity of the phase is too low, so the corrosion of the magnet starts from the boundary phase, and once the corrosion reaction occurs, H 2 , and aggravate the destruction of the magnet, making the magnet into powder, which will cause the coating to bliste...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/057H01F41/02B22F1/02B22F9/04
Inventor 熊永飞衣晓飞陈静武
Owner EARTH PANDA ADVANCE MAGNETIC MATERIAL
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