Electroless nickel-phosphorus plating process for Nd-Fe-Bo permanent magnet material

Abstract

The invention discloses a chemical plating nickel plating method of neodymium-iron- boron permanent magnet material, which is characterized by the following: adopting plugging chemical plating to plug neodymium-iron-boron and thick and block-up neutral chemical plating; carrying on chemical plating nickel phosphor method of acidic high-phosphorus chemical plating, wherein the method comprises the following steps: tumbling; chamfering; degreasing; derusting; activating; plugging chemical plating; neutering chemical plating; acidifying high-phosphorus chemical plating; inactivating. The invention simplifies the application of industry, which reduces cost of production.

Description

technical field [0001] The invention relates to the field of surface chemical treatment of powder metallurgy materials and easily corroded materials in acid-base solutions, in particular to an electroless nickel-phosphorus plating method for neodymium-iron-boron permanent magnet materials. Background technique [0002] NdFeB permanent magnet is currently the most magnetic permanent magnet material. It has excellent properties such as high energy product, high coercive force, high remanence and high performance-price ratio, and has become an important functional material in the modern high-tech field. . However, because the lanthanide metal Nd is extremely active in humid air and acid-base solution, it is easy to be oxidized and corroded. At the same time, the powder metallurgy sintering process makes the surface of the material have many micropores, which makes the surface difficult to handle and makes its corrosion resistance poor. The magnetic performance of the permanent...

AI Technical Summary

Problems solved by technology

However, because the lanthanide metal Nd is extremely active in humid air and acid-base solution, it is easy to be oxidized and corroded. At the same time, the powder metallurgy sintering process makes the surface of the material have many micropores, which makes the surface difficult to handle and makes its corrosion resistance poor. The magnetic performance of the permanent magnet is greatly reduced, which seriously affects the application of the permanent magnet

In the existing technology, organic coating methods, electroplating and electroless plating are mostly used for surface treatment of NdFeB materials, and some effects have been achieved, but there is still the problem of poor corrosion resistance.

Electroless nickel plating or electroplating nickel-copper-nickel composite coating is generally used as a protective layer in the world. Among them, the electroless nickel plating has a large porosity and poor corrosion resistance, while electroplating has problems such as uneven thickness, unstable coating quality and environmental pollution.

It has been reported that ultrasonic electroless plating and neutral acid composite plating have good results, but no industrial application has been seen. Industrial equipment for ultrasonic electroless plating is difficult to implement, and neutral acid composite plating cannot solve the microporous problem of permanent magnets.