Multilayer composite protective coating on surface of sintered NdFeB magnet by multi-arc ion plating and process thereof

Abstract

The invention belongs to the technical field of surface protective coating, and particularly relates to a multilayer composite protective coating on the surface of a sintered NdFeB magnet by multi-arc ion plating and a process thereof. By adopting the multi-arc ion plating deposition technology, a transition layer, a corrosion-proofing layer and a surface barrier and wearing layer composite protective coating are prepared on the surface of the sintered NdFeB magnet, the corrosion resistance of the sintered NdFeB magnet is obviously improved, and the service life is prolonged. The process comprises the following steps: (1) removing oil and rust on the surface of a magnet, cleaning the surface; (2) cleaning the surface by glow discharge backwashing in a vacuum coating chamber; (3) preparing a Ti or Cr transition layer by multi-arc ion plating; (4) preparing Al or Al alloy by multi-arc ion plating; (5) preparing an AlN layer by multi-arc ion plating. By adopting the arc ion coating technology and combining the design of a multifunctional layered composite structure coating system, the process has the characteristics of high deposition efficiency, high coating binding force and compactness, simple process, environmental friendliness, no pollution and low cost, and batch large-scale production is easy to realize.

Description

technical field [0001] The invention belongs to the technical field of surface protective coatings, in particular to a multi-layer composite protective coating prepared by multi-arc ion plating on the surface of a sintered Nd-Fe-B magnet and a process for preparing a composite protective coating on an Nd-Fe-B magnet by using the multi-arc ion plating technology Layers: Ti or Cr transition layer, corrosion-resistant Al or Al alloy middle layer, and barrier and wear-resistant AlN outer layer. Background technique [0002] NdFeB permanent magnet is the third generation of rare earth permanent magnet after Sm-Co permanent magnet. Due to its excellent magnetic properties and my country's rich neodymium resources, its research, development and production have developed rapidly. However, due to the chemical composition of the material and the powder metallurgy production process, its surface is easily oxidized and corroded in the use environment, resulting in a decrease in its magn...

AI Technical Summary

Problems solved by technology

Up to now, vacuum evaporation is mainly used for aluminum plating on NdFeB, which can be coated in large quantities, and the coating efficiency is also high. However, the bonding force between the vacuum evaporated aluminum film and the substrate is poor, and defects such as pinholes are prone to occur in the film.

At the same time, magnetron sputtering technology is also used, which can improve the bonding force between the film and the substrate and the compactness of the film, but the coating rate of this technology is low, the production efficiency is correspondingly low, and the bonding force still cannot meet the requirements.

Images