JPS619551A - Rare earth element-iron type permanent magnet alloy - Google Patents

Abstract

PURPOSE:To obtain a rare earth element-iron type permanent magnet alloy having high magnetic flux density and high coercive force even in the form of a bulk material formed by a sintering method by which a material is easily worked into a desired shape by providing a specified composition. CONSTITUTION:This rare earth element-iron type permanent magnet alloy has a composition represented by the formula, wherein alpha, beta and gamma are atomic ratio, R is at least one kind of element selected among Y and rare earth elements, X is one or more among B, C, N, O, P, H, S, Al and Si, M is one or more among Ag, Pt, Pd, Rh, Re, Ge and Ru, 0.001<=alpha<=0.5, 0.5<=beta<=0.95, 0.001<=gamma<=0.1, and alpha+beta+gamma<1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a rare earth iron-based permanent magnet alloy.

[Technical background of the invention and its problems] Intermetallic compounds consisting of rare earth metals (R) and iron (Fe) have large crystal magnetic anisotropy and high saturation magnetization, and have high coercive force and high energy product. It is promising as a permanent magnet alloy having the following characteristics, and has the advantage that the raw material is cheaper than conventional rare earth cobalt magnets. In particular, 几・Fe
Research is being done on improving performance by adding a third component to (8.58゜ Japan Institute of Metals Autumn Conference Proceedings P
, 681, JP-A-59-46008, etc.).

However, when conventional rare earth iron-based permanent magnet alloys are melted, crushed, and then sintered to form a bulk shape, even after optimal heat treatment, only a low coercive force can be obtained, making it difficult to obtain practical permanent magnets. It was insufficient as a magnet.

In particular, one cucumber is not enough when considering practicality.
Problems remain.

[Purpose of the invention]

The present invention has been developed in consideration of the above-mentioned problems, and even if a bulk material is formed by a sintering method that allows easy processing into arbitrary shapes, it has high magnetic flux density, high coercive force, and maintains a high energy product. It is an object of the present invention to provide a rare earth iron-based permanent magnet alloy that has excellent temperature conditions.

[Summary of the invention]

The present invention is a rare earth iron-based permanent magnet alloy that has excellent magnetic properties even when a fourth element is added to a rare earth iron-based R-X-Fe system and a bulk material is formed by a normal sintering method.
The following formula % formula % where α, β, r are the atomic ratio RAM and at least one rare earth element X: B, C, N, 0. At least one type M selected from P, H, 8, A/, and 81; At least one type selected from Person g, Pt, Pd, Rh, Re, Ge, and (JRu 0.0001≦α≦0.5 0. 5≦β≦0.95 0.001≦γ≦0.1 α+β+r(1,0).

In the present invention, the third element X added to the R-Fe system is Be C+ N* Os P+ Hr 8. IJH8
By adding these third elements X, a stable tetragonal crystal structure is obtained in the ternary system of R-X-Fe, and magnetic The coercive force is improved by imparting a certain anisotropy.

As X, B and C are particularly effective.

In this case, if the atomic ratio of the addition amount α of If a large amount of X is added exceeding the above range, the magnetic flux density will decrease, so the amount α of X to be added is defined in the above range. Preferably 0.0
The range is 4≦α≦0.20.

The fourth element M is T, Ag, Pt, Pd, fLh,
Mention may be made of Re, Ge and Ru. By adding this M, the Curie point increases by one point. This is thought to be due to the increased interatomic distance of Fe. The amount of M added is 0
．． If it is less than 001, the effect of raising Curie by one point cannot be obtained, and 0
．． If it exceeds 1, the magnetic flux density and coercive force will not only decrease, but will not increase by a single point. Preferably 0.005≦r
Particularly effective is ≦0.04.

Fe has an effective effect in improving the magnetic flux density in the magnet alloy of the present invention, and if the added amount β is less than 0.5, a sufficient tetragonal crystal structure cannot be obtained and the magnetic flux density also decreases. . Further, if the amount of Fe added exceeds 0.95 and the coercive force decreases, it is necessary to specify the above range, and the range of 0.6≦β≦0.86 is particularly preferable.

Rare earth elements R include Ce, Pr, Nd, 8m
, M, M (mitshu metal), etc., these Y and R are essential elements to improve coercive force,
If the amount added is small, the coercive force will be extremely reduced, so O
, OS to O, aO is preferable.

The alloy having the above composition is, for example, melted, crushed, and then compacted.
After the obtained green compact is sintered, it can be formed by a generally known method such as performing heat treatment to form a permanent magnet.

〔Effect of the invention〕

According to the rare earth iron-based permanent magnet alloy according to the present invention, even if a bulk material is formed by a sintering method that allows easy processing into any shape, it has a high magnetic flux density, a high coercive force, and a high energy product. It also has remarkable effects such as a high curri point and excellent temperature characteristics.

[Embodiments of the invention]

(Example) Alloy samples having the composition shown in Table 1 were high-frequency melted, coarsely pulverized using a Joke 2 Tsushear Brown mill, and then finely pulverized using a jet mill. In this case, N gas is used as the grinding medium, and the average particle size of the obtained particles is 5 μm. After orienting this fine powder in a magnetic field of 15 KOe, it was compressed and molded by pressing at a pressure of 2 torr perpendicular to the direction of magnetic field application.
A plate-shaped powder compact having Q, m, lateral IQax and thickness of 83El+ was obtained.

Next, the powder compact is sintered and then subjected to heat treatment to form a permanent magnet, the residual magnetic flux density of which is Br.

Coercion crab zHc and maximum energy product: (BH)
max was measured and the results are shown in Table 1.

The sintering conditions and heat treatment conditions for the compacted compact are as follows: A, the compacted compact is sintered at 1100°C for 1 hour in an argon atmosphere. After that, aging treatment is performed at 600°C for 2 hours.

B: After sintering the powder compact in an argon atmosphere at 1080°C for 1 hour, it is subjected to two-step aging treatment at 650°C for 1 hour and 550°C for 2 hours.

C: After sintering the compacted powder in an argon atmosphere at 1050° C. for 1 hour, aging treatment is performed at 550° C. for 2 hours, and then controlled cooling is performed at a cooling rate of 1° C./min to room temperature.

(However, the sintering temperature is within the range of ±10°C) (Comparative example) In order to compare with the present invention magnet alloy, the conventional 几-B-Fe
Alloy, even if alloy I falls outside the scope of the present invention,
A permanent magnet was manufactured in the same manner as in the above example.

This magnetic property was also measured in the same way, and the results were used as a second
Also listed in the table.

As is clear from the results shown in Table 1 and Table 2 above, the rare earth iron-based permanent magnet alloy according to the present invention has high performance even when a bulk material is formed by a sintering method that allows easy processing into any shape. It has a high magnetic flux density, high coercive force, high energy product, and has a remarkable effect with a high Curie point.

In addition, to improve corrosion resistance, Ni, Mg, Cr +
Ti+kl' system may be contained in an amount of about 0.1 to 1Qatm%. (Hidden 4).

Claims (1)

[Claims] The following formula R_1_-_α_-_β_-_γXαFe_βMγ where α, β, and γ are the atomic ratio R; Y and at least one rare earth element X; B, C, N, O, P, H, S, Al and at least one selected from Si; at least one selected from Ag, Pt, Pd, Rh, Re, Ge, and Ru 0.001≦α≦0.5 0.5≦β≦0.95 0.001 A rare earth iron-based permanent magnet alloy having a composition expressed by ≦γ≦0.1 α+β+γ<1.0.