Rare-earth permanent magnet particle material for injection molding and preparation method thereof

Abstract

The invention discloses a rare-earth permanent magnet particle material for injection molding, and further comprises a preparation method of the rare-earth permanent magnet particle material for injection molding. The rare-earth permanent magnet particle material is prepared from the following raw materials in parts by weight: 60-80 parts of rare-earth permanent magnet powder, 5-15 parts of resin,2-6 parts of an organic solvent, 1-3 parts of a reinforcing agent, 1-3 parts of a passivator, and 0.5-2 parts of an antioxidant. According to a formula and the preparation method of the rare-earth permanent magnet particle material, acetic acid, oxalic acid and formic acid are selected as a surface passivator of the magnetic powder, after passivation, a passivation layer not prone to oxidation isformed on the surface of the rare-earth permanent magnet powder, thus oxidation of the rare-earth permanent magnet powder during high-temperature granulation and high-temperature injection molding isreduced, and the performance of the rare-earth permanent magnet powder is ensured; and a certain quantity of the reinforcing agent is added to modify resin, the strength of master batch is improved,and the application range of the rare-earth permanent magnet particle material for injection molding and a product is expanded. The problems of oxidation of the rare-earth permanent magnet powder during high-temperature granulation and high-temperature injection molding at the present stage, oxidation and rusting in the using process of the product, and the like are well solved.

Description

technical field [0001] The invention relates to a magnetic material and a related preparation method, in particular to a rare earth permanent magnet particle material for injection molding and a preparation method thereof. Background technique [0002] Bonded magnets are polymer-based composite permanent magnet materials made of magnetic powder and binders such as resin, rubber or low-melting point metals, and then made by injection molding, compression molding or extrusion molding. an important branch of . The injection molding method is to mix and granulate the magnetic powder and resin powder, and then inject the granulated granules into the injection molding machine to heat and melt them to make them have good fluidity. In this state, the granules are melted The state is injected into a metal mold with an orientation magnetic field, and after cooling, the required complex shape of the magnet product is formed. Compared with general compression molding, the advantages o...

AI Technical Summary

Problems solved by technology

At present, there are several main problems in rare earth permanent magnet pellets for injection molding: First, since rare earth permanent magnets (mainly including NdFeB and SmFeN) are metal materials, they are easily oxidized at the granulation temperature of 220°C-350°C, thus It affects the magnetic properties of the pellets; second, during use, such as high temperature environment and water environment (such as water pump rotor), it will cause oxidation and rust of injection molded rare earth permanent magnet products, which greatly affects the service life

However, this invention improves the weather resistance of the material by forming a phosphate film, not by improving the components, so it is of little reference value for rare earth permanent magnet materials for injection molding