JPS58190006A - Manufacture of oxide permanent magnet - Google Patents

Abstract

PURPOSE:To improve hygroscopic property and prevent white powder forming on a surface during drying, by a method wherein a gap of the magnet is filled with an impregnating substance of resin or adhesive agent solved by a solvent. CONSTITUTION:A dimethyl acrylate adhesive agent of low viscosity for impregnation treatment is impregnated at vacuum condition in burning product of Sr- ferrite magnet. The impregnated product is machined by a diamond wheel using a cooling water and then left alone. After the lapse of several tens of hours, hygroscopic property is little and white powder is not observed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sintered body density of a sintered magnet, and more particularly to improving the mechanical properties of a magnet. .

Conventional sintered magnets are manufactured by crushing, mixing, molding, and firing raw materials, and the mechanical properties of these magnets are as follows:
Composition conditions and firing conditions are optimally set to obtain the desired magnetic properties even in magnets.

Determined by circumstances. The density of the fired oxide permanent magnet thus obtained was 95% or more of the normal theoretical density, and its mechanical strength and water absorption did not cause any particular trouble.

Recently, especially oxide permanent magnets, which have high coercive force.

Although demand is increasing, such magnets generally have a lower firing density than conventional materials, and have problems with mechanical properties and water absorption/water absorption.

Further, the density of the fired body is 95% or less of the theoretical density, and voids of 5% or more exist in and inside the fired body, which is the cause of the water absorption property of the fired body. Oxide permanent magnets generally use a large shake of water during finishing.

In the process of drying the processed fired product, the water contained in the process dissolves a part of the oxide permanent magnet and precipitates on the surface, producing white powder. It has the following.

The present invention solves the above-mentioned problems and drawbacks.

To provide an oxide permanent magnet with excellent mechanical properties.

The purpose is to Another purpose is...

This article relates to prevention of white powder depositing on the surface of an oxide permanent magnet.

In carrying out the object of the invention, an oxide permanent magnet.

The cavity of the magnet is filled with a resin dissolved in a solvent.

is a filler made of adhesive and is an empty part of the permanent magnet.

It is characterized by being filled with. 211
The present invention will be explained in detail below.

Example 1 Sr-ferrite with a fired density of 89.4% of the theoretical density.

To process and finish the fired body of the magnet, process it using a diamond wheel while using cooling water, then dry it by holding it at 100°C for 1 hour to form an insulating face.

After applying and coating the surface, it was left in water for a day and a night. This was re-dried at room temperature, but no white powder was generated even after several tens of hours had passed. On the other hand, this etc.

The untreated fired body has Il+ inside it.
The penetrating water dissolves a portion of the Sr-ferrite magnet.

As this dries, it gathers on the surface and forms a white powder.

The product treated according to this example has no sulfur content.

There was little aqueous content and no white powder was observed.　　.

Example 215 Sr-ferrite magnet similar to that described in Example 1.

Low viscosity dimethyl acrylic for impregnation treatment on the fired body.

-F-based adhesive was applied by vacuum impregnation. Next, add this in the evening.

After processing with Yamond wheel using cooling water.

I left it alone. Even after several tens of hours, a white powder appears.2. .

・　3　・ do not have. - Untreated firing without treatment of strength wood examples.

Although white powder was observed on the surface of the adult, this test was not carried out.

The treated ones have less water absorption and are white in color.

No powder was seen.

Furthermore, by performing this treatment, the infiltrated resin 5 becomes polyacrylate after curing, thereby becoming Sr.

Mechanical properties such as strength and impact resistance of ferrite magnets.

The holding power of magnetic properties is slightly higher than that of conventional products.

Improvements can be seen, and these same characteristics have been revised.

Things are getting better. As explained above, the present invention is a low-density ferra.

・Various surface coatings of fired magnets.

Improves water absorption and generates water on the surface when drying.

It also prevents the formation of white powder.

It has great industrial benefits, such as improved mechanical properties such as strength and impact resistance, and coercive force, which are unique to conventional magnets.

I was able to get results.

・　4　・

Claims (1)

[Claims] An oxide permanent magnet obtained by molding and sintering powder, characterized in that the voids in the permanent magnet are filled with a filler made of a resin or an adhesive dissolved in a solvent. A method for producing an oxide permanent magnet.