Method for reducing porosity of surface coating of neodymium iron boron permanent magnet material

Abstract

The invention discloses a method for reducing porosity of a surface coating of a neodymium iron boron permanent magnet material, belonging to the field of surface treatment of sintered neodymium ironboron permanent magnet materials. The method is characterized by comprising the steps of 1) deashing a neodymium iron boron permanent magnet material; 2) soaking the neodymium iron boron permanent magnet material in a sealant, and then carrying out water washing, wherein the sealant is an alcohol amine compound; 3) sequentially cleaning the wahsed neodymium iron boron permanent magnet material through an oil removal agent and an acid; and 4) activating the neodymium iron boron permanent magnet material, and then carrying out electroplating. According to the method for reducing the porosity ofthe surface coating of the neodymium iron boron permanent magnet material, hole sealing treatment is carried out before electroplating, water is sucked into gaps through capillary action, and oxide inthe gaps generates hydrated oxide through hydration, so that the volume of the oxide is increased, and the gaps are sealed; and furthermore, the porosity of the coating can be reduced, the coating isrelatively smooth and bright, and the magnetic flux loss of the magnet can be reduced.

Description

technical field [0001] The invention discloses a method for reducing the porosity of a surface coating of an NdFeB permanent magnet material, which belongs to the field of surface treatment of sintered NdFeB permanent magnet materials. Background technique [0002] NdFeB permanent magnet materials, known as the "King of Permanent Magnets", have been widely used in various fields such as military, medical and environmental protection since their inception, and are favored by people. However, the manufacture of NdFeB permanent magnet materials is a powder metallurgy process. Like other powder materials, the structure is loose and the porosity is high. During the electroplating process, the solution easily penetrates into the pores and is not easy to clean. The magnetic material is composed of a variety of phases with different electrode potentials, and micro-battery reactions are extremely prone to occur, causing the NdFeB and the coating to corrode laterally during use and st...

AI Technical Summary

Problems solved by technology

However, the manufacture of NdFeB permanent magnet materials is a powder metallurgy process. Like other powder materials, the structure is loose and the porosity is high. During the electroplating process, the solution easily penetrates into the pores and is not easy to clean. The magnetic material is composed of a variety of phases with different electrode potentials, and micro-battery reactions are extremely prone to occur, causing the NdFeB and the coating to corrode laterally during use and storage, resulting in a decrease in the bonding force of the coating, bubbling and peeling of the coating, and the material Pulverization, etc.