Clad powder for powdered iron core and preparation process for clad powder

Abstract

The invention discloses clad powder for a powdered iron core and a preparation process for the clad powder. The clad powder for the powdered iron core is prepared by adopting a ball milling method; the clad powder contains iron powder, organic insulating agent and lubricating agent serving as raw materials; and particularly, an inorganic nano oxide is added in the clad powder. In the preparation process, insulated cladding of the powder is realized, meanwhile, organic resin is effectively modified by nano particles, and the heat resistant temperature of the organic resin is improved; and in high-temperature annealing of the subsequent powdered iron core product, completeness of an insulated film is kept, thermal decomposition of the powdered iron core is reduced, and the annealing temperature is improved. The clad powder has good process properties such as forming property, flowability and the like; the powdered iron core with high compactness and great improvement on mechanical property and magnetic conductivity can be stamped by using the clad powder as a raw material; the utilization rate of the raw material is high; the powdered iron core has the same orientation in each direction and is more convenient for three-dimensional shape machining of a subsequent product with low cost; and the subsequent machined product can reduce eddy current loss when used in a high-frequency area of an alternating-current external field, and can partially replace the traditional laminated iron core.

Description

technical field [0001] The invention belongs to the field of new functional materials, and relates to a coated powder for powdered iron core and its preparation process. The coated powder of the invention is used to make magnetic cores in transformers and inductors, motors and other electronic components. Powder core. Background technique [0002] Iron powder cores currently on the market are mainly laminated with stamped silicon steel sheets into silicon steel sheets, and then machined into laminated iron cores, which are used to make iron cores for various transformers, motors and generators. Silicon steel sheet, also known as electrical steel, is a ferrosilicon soft magnetic alloy with extremely low carbon content. Generally, the silicon content is 0.5-4.5%. The iron core made of silicon steel sheet has high magnetic permeability and low iron loss, and is widely used. , but the preparation process is cumbersome, requires stamping and cannot be formed at one time, the uti...

AI Technical Summary

Problems solved by technology

However, during the preparation process of powdered iron core, a large pressing pressure is applied to form the coated powder to increase the density of the magnetic powder core, and there is inevitably a large internal stress in the compact. In order to release the pressure in the compact In order to improve the mechanical properties of the magnetic powder core and improve the magnetic properties of the magnetic powder core, the residual stress needs to be annealed, and the temperature is generally between 400-600 °C. Among them, the insulating coating coated on the surface of the particles is generally an organic insulating film, which will inevitably decompose and carbonize during the annealing process, thereby deteriorating the magnetic properties of the magnetic powder core, which in turn leads to increased eddy current loss when used in the high-frequency area of ​​the AC external field. Big, so far there is no very effective solution

Therefore, the preparation of coated powder by chemical coating method has certain shortcomings and cannot be popularized and applied.

[0008] Hoganas is the largest and most experienced iron-based powder production group in the world. The Somaloy series powder produced by the company is a coating powder suitable for preparing powdered iron cores, but in practical applications, the Somaloy series powder The powdered iron core prepared by one-time powder processing has poor mechanical properties, and the pressing pressure is less than 400MPa, which is prone to edge drop and corner drop. The organic resin in the powder will be decomposed in a large amount, which will seriously damage the mechanical properties, magnetic properties and other comprehensive properties of the powdered iron core; in addition, the Somaloy series powder is expensive, and this series of factors limits the popularization and application of the coated powder, making the dusted iron core unusable. Cannot replace traditional laminated iron core

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