JPS59232228A - Manufacture of magnetic fe-si-al alloy - Google Patents

Abstract

PURPOSE:To obtain a magnetic Fe-Si-Al alloy of high quality at a low cost by coating the surface of an Fe-Si-Al alloy casting with fine particles of an oxide, a nitride or a carbide which is not dissociated even under conditions during hot hydrostatic pressing, and subjecting the coated casting to hot hydrostatic pressing. CONSTITUTION:An Fe-Si-Al alloy contg. about 9.8wt% Si and about 6.3wt% Al is cast. The surface of the casting is coated with fine particles of an oxide such as Al2O3, MgO or CaO, a nitride such as BN or Si3N4, or a carbide such as TiC or SiC which is not dissociated even under conditions during hot hydrostatic pressing. The coated casting is subjected to hot hydrostatic pressing to obtain a magnetic Fe-Si-Al alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a magnetic alloy containing F″e, Si, AI, particularly after casting said magnetic alloy.

By subjecting the magnetic alloy to hot isostatic pressing (hereinafter abbreviated as H-P), casting defects are removed without causing compositional fluctuations, and a high-quality magnetic alloy is obtained. -This invention relates to a method for producing an Al-based magnetic alloy.

Fe-8l-Al alloy contains 4-12% by weight Si,
A composition range of 3 to 8% by weight A1, or a range containing 10% by weight or less of additive elements in total.

It has excellent magnetic properties such as high magnetic permeability and high saturation magnetic flux density, and at the same time exhibits excellent wear resistance, and is widely used as a core material for magnetic heads.

Generally, Fe-8i-Al alloys are manufactured by vacuum melting, but since they contain large amounts of Si and Al,
The problem is that the shrinkage during solidification is large, and there are many defects such as cavities and microcracks inside the cast body, resulting in a significant decrease in the monthly yield and an increase in casting cost.

On the other hand, HIP processing, which has been used in the production of hard tool materials in recent years, is an effective means for removing defects in the cast body, and is used. In this case, deterioration of magnetic properties occurs due to new causes described below.

Pressure media used for HIP processing include Ar, N2
However, these gases of industrial purity contain a large amount of 02 gas. For example, Ar gas is 60
~60PPm. The present inventors have discovered that the 02 gas in the pressure medium gas contains Si, AI, which has a strong affinity with +o2 among the components of the Fe-8i-Al alloy cast body.
This can cause significant fluctuations in

It has been found that this is the cause of the deterioration of magnetic properties.

Therefore, if an ultra-high purity gas with a significantly low oxygen partial pressure is used, this problem can be alleviated, but since ultra-high purity gas is expensive, it is disadvantageous to use it for industrial purposes.

The object of the present invention is to produce high quality Fe-8i- at low cost.
Fe-3i- capable of producing Al-based magnetic alloys
An object of the present invention is to provide a method for manufacturing an Al-based magnetic alloy.

According to the present invention, a cast body of an alloy containing Fe, Si, and Al is obtained, and the surface of the cast body is subjected to hot isostatic pressing (HIP).
) Fe-8i-, which is characterized in that the cast body is coated with fine particles made of any one of oxides, nitrides, and carbides that do not dissociate under the following conditions, and then subjected to hot isostatic pressing (HIP) treatment. A method for producing an Al-based magnetic alloy is obtained.

Next, the present invention will be described in detail with reference to the drawings.

In the conventional I-T IP treatment of Fe-8i-Al alloy, the cast body is loaded as is into the HIP treatment container.
00~1600℃, 1000~2000 Kq/c
This is a method of raising the temperature and pressure to nY, but in this method, as mentioned above, 02 in the pressure medium gas is Fe-8i-Al
81. of system alloy components. Reacts with AI, resulting in excess Sj, Al near the surface of the cast body.

The cast body is a Fe-8i-Al alloy containing 9.8% by weight of Si and 6.3% by weight of AI, and the size of this cast body is on the order of 100×100×30.

This cast body was subjected to the conventional H-P treatment described above,
The Fe results obtained after HIP treatment are the first
Shown in the figure. According to this, approximately 4.0 mm from the surface of the cast body.
Si over 5 pharynx depths.

It is clear that the composition of AI fluctuates and is excessive. This is clearly an influence of 02. Therefore, in the conventional H-P process, in order to obtain a Fe-8i-Al alloy with a uniform composition after the HiP process, grinding of at least 4.5 mm or more from the surface of the cast body is required for quality reasons.

On the other hand, according to the present invention, the surface of the Fe-8i-Al alloy cast body is subjected to at least HIP treatment f7M W from room temperature.
In the HIP treatment, the material is coated with an oxide, nitride, or carbide that is thermally and chemically stable, and then subjected to HIP treatment in this state.

Reactions between Si and Al, which are components of the Fe-5i-Al alloy cast body, and the 02 gas in the pressure medium gas can be avoided.

It becomes possible to produce a high quality and low cost Fe-Si-Al alloy.

Hereinafter, one aspect of the present invention will be explained in detail.

[Example 1] The Fe-5i-Al alloy cast body (with Si of 9.8
wt%, containing 6.3 wt% AI) to alumina A, 1
After coating with 203, H-P treatment was performed.

XMA analysis of Eli and AI fluctuations of cast bodies after HIP treatment
Figure 2 shows the results of the investigation. The fluctuations in Si and AI of the cast body coated with Hachi1203 were slightly 0 compared to the surface.
．． The range of variation in Si and AI is % compared to the conventional method that does not cover the depth.

[Example 2] The above Fe-5i-Al alloy cast body (Si: 9.8
(wt%, containing 6.3 wt% Al) boron nitride BN
It was coated with H-P treatment. Figure 6 shows the results of investigating the fluctuations of Si and Al in the cast body after HIP treatment using X1φA. Si of the cast body coated with BN,
The fluctuation of Al is only up to a depth of 0.6u from the surface, and the fluctuation range of Si and Al is only 'l/A5 compared to the conventional method without coating.

In addition, sample piece E was selected from the portion where +AI+81 of the "e-8i-Al alloy of Examples 1 and 2 and the Fe-8i-A] alloy obtained by the conventional method had little variation.

Table 1 shows the average value and standard deviation of the effective magnetic permeability/le measured by cutting out. However, it was annealed under the same conditions after H-P treatment. Furthermore, the number of measurements was 20. The Fe-5i-AI alloy obtained by the present invention has an improved μe compared to the conventional method, and its standard deviation is small.

Table 1 As described above, according to the present invention, it is possible to easily produce a high quality and low cost Fe-8i-AI magnetic alloy.

Although the present invention has been explained above, +A1203 +B
In addition to N, Mg O, Zr 02 , Oa O, Ti
02, SiO□.

Si3N4. 1300℃ for TiC, SiC, etc. 2
It is sufficient to use fine particles that do not dissociate even under high temperature and high pressure of about 000 K9/c4, and the method of coating may be by brushing, spray painting, sputtering, vapor deposition, etc., and is not subject to any restrictions.

[Brief explanation of the drawing]

Figure 1 shows Fe-8i obtained by conventional HIP processing.
-The amount of Si and Al from the surface of the Al-based alloy casting to a depth of 11]+u+ was measured using an X-ray microanalyzer (XMA
) is a diagram showing the results of an investigation. Figure 2 shows the amount of Si and Al from the surface of the cast body up to a depth of 10 mm after the surface of the Fe-8i-Al alloy cast body is coated with Al2O3 and subjected to HIP treatment according to the present invention. It is a figure showing the result of investigation by. FIG. 6 shows the surface of a Fe-8i-Al alloy cast body coated with BN and subjected to H-P treatment according to the present invention. lEi from the surface of the casting to a depth of 10 m, A
1 is a diagram showing the results of investigating the amount of l by XMA. -('・c'ζ. fe N people (7127) it 1i% after filling Yosuke-,'a,'1@distance from the surface of the Chinese body (mm) Fig. 1 Distance between the surface forces of the casting surface (mm') Fig. 2 Cast body surface Tsu・ra talus Fig. 3 Procedural amendments spontaneously) February 78, 1932, Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the case 1982 Patent Application No. 105421 No. 2, Title of invention: Method for producing Fe-8i-112 magnetic alloy 3 Relationship with the case of the person making the amendment Patent applicant 4, Agent Address: 1-4-10 Nishi-Shinbashi, Minato-ku, Tokyo 105 Mimori Building
Place 59N-1507/1526 Name (5841)
Patent Attorney Ashi 1) Tan (and 2 others) 6. Change r30-60J to "1-20" on page 3, line 3 of the statement of contents of the amendment. 7j-5, ::'

Claims (1)

[Claims] 1. Obtain a cast body of an alloy containing Fe, Si, A1,
After coating the surface of the cast body with fine particles made of any one of oxides, nitrides, and carbides that do not dissociate even under hot isostatic pressing conditions, the cast body is subjected to hot isostatic pressing treatment. A method for producing a featured Fe-8i-Al magnetic alloy.