Lubricant for preparing NdFeB magnets by powder metallurgy and its application method

Abstract

The present invention relates to the technical field of powder metallurgy additives, in particular to a lubricant for preparing neodymium-iron-boron magnets by powder metallurgy and a method of use. The lubricant includes a solute and a solvent, and the solute is selected from 2-aminobenzothiazole and borate One or two of them; the solvent is selected from one or more of chloroform, diethyl ether and petroleum ether, and the mass ratio of solute to solvent is 0.5:99.5 to 5:95; the lubricant is used in powder metallurgy to prepare NdFeB magnets The method of use mainly includes blowing the lubricant into the NdFeB powder mixing tank through an inert gas, mixing the powder in the 3D mixer, mixing evenly, the lubricant is evenly coated on the surface of the particles, and then molded and sintered at high temperature Obtaining NdFeB magnets, the lubricant of the present invention can increase the fluidity of the powder, effectively solve the problem of powder agglomeration, and has good lubricity. The addition amount of NdFeB powder is small, and the purpose of lubrication can be achieved with a small addition amount. The introduction of harmful elements in the magnet is reduced.

Description

technical field [0001] The invention relates to the technical field of powder metallurgy additives, in particular to a lubricant for preparing NdFeB magnets by powder metallurgy and a use method. Background technique [0002] Powder metallurgy is a process technology that uses metal powder or a mixture of metal powder and non-metal powder as raw material, after molding and sintering, to manufacture metal materials and various products. Lubricants are usually added to the raw materials for better fusion of fine particles and release of the green compact. The uniformity of dispersion of various lubricants in the compact directly affects the demoulding effect, and even more affects the defective rate of the compact. [0003] As a basic functional material, sintered rare earth permanent magnet NdFeB materials are widely used in electric vehicles, hybrid vehicles, wind power generation, inverter air conditioners, medical equipment, elevators, audio equipment and mineral separati...

AI Technical Summary

Problems solved by technology

Zinc stearate is the most commonly used in this type of material, such as Chinese patent CN102672164 and Chinese patent CN107952953, all use zinc stearate as a powder metallurgy lubricant, but it cannot be completely decomposed into gaseous substances during the sintering process and there are metal residues Oxide pollution sintering furnace and parts

Chinese patent CN102942980 and Chinese patent CN104994976 both use higher fatty acids, amides and their derivatives to form lubricants. Although this type of lubricant has good lubricity, the cohesive force of the particles is relatively large, which may cause agglomeration of the mixed powder during storage. , can reduce the fluidity of the powder

Traditional powder metallurgy lubricants are not suitable for rare earth permanent magnet materials, so there are very few types of lubricants required in the production process of NdFeB on the market