JPS59143038A - Magnet alloy - Google Patents

Abstract

PURPOSE:To provide a rare earth-cobalt magnet alloy which has a good magnetic characteristic and is low in material cost by specifying the compsn. of an alloy consisting of REM, Fe, Cu, Nb, etc., Te, etc. and Co thereby improving cracking and chipping properties and improving the yield of product. CONSTITUTION:A rare earth-cobalt magnet alloy consists of 20-30wt% REM, 5-40% Fe, 2-15% Cu, 0.1-10% >=1 kind among Nb, Ti, Zr and V, 0.01-2% 1 or 2 kinds of Te and Se or in combination with S, and the balance substantially Co. Co in the R2Co17 magnet alloy is substd. with a proper amt. of Fe, Cu, Nb, Ti, Zr, V, etc. to improve cracking and chipping properties. Nb, Ti, Zr, V, etc. in combination with an adequate atm. of Fe and Cu exhibit an extremely high magnetic characteristics. Te, Se, etc. are effective in improving the cracking and chipping properties of the magnet.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rare earth cobalt based magnet alloy with improved cracking and chipping properties.

Rare earth cobalt magnet alloys have significantly better magnetic properties than alnico and ferrite magnet alloys, so their uses have been expanding in a wide range of fields in recent years, and production has been increasing rapidly in recent years.

Initially, the mainstream of this rare earth cobalt magnet alloy was the RC05 series magnet alloy, which had a high coercive force, but recently, R2Co, 7 series magnet alloys with various additive elements have been used to obtain higher magnetic properties. , R(REM) is small, so the raw material cost is low, and so on.

However, although the R2Co, 7-based magnet alloy has the above-mentioned advantages over the RCo5 alloy, it has the disadvantage of being hard and brittle, resulting in poor yields during the manufacturing process, which poses production problems. This tendency is particularly noticeable in R2Co17-based magnet alloys with high magnetic properties in which a portion of +R2Co, 7R2C017-based magnet alloys are replaced with appropriate amounts of Cu, Fe, Ti, Zr, V, Nb, etc.

Therefore, the present inventors conducted experimental research with the aim of improving these defects, and as a result of investigating the causes of cracks and chips in R2C017 magnet alloy, it was found that the above-mentioned cracks and chips were caused by grain boundaries. After confirming what was happening, I was able to complete this invention.

That is, the magnet alloy according to the present invention has a weight ratio of R,
EM (one or more rare earth elements including Y).

20-30%, Fe: 5-40%, Cu: 2-15%,
and one or more of Zr, Ti, Nb, and V in a total content of 11 to 10% O and roughly Te.

A total of 0.1 or 2 Se or a combination with its.
01 to 2%, and the remainder substantially consists of Co.

The reasons for limiting the component range (weight ratio) of the rare earth cobalt magnet alloy according to the present invention will be explained below.

REM: 20-30% REM mainly contains Sm, Ce, and Y.

It is a general term for one or more rare earth elements such as La and Pr, and if this REM is less than 20%,
This is not preferable because both the residual magnetic flux density (Br) and the coercive force (IHC, BHC) become significantly low.
), which is not desirable. Therefore, R
EMFe: 5-40% Fe has saturation magnetization (4πIs) and residual magnetic flux density (Br
), but if it is less than 5%, the effect is small, and if it exceeds 40%, it will increase the coercive force (IHC).
, BHC) becomes significantly low, which is not desirable for practical purposes, so it is set in the range of 5 to 40%.

Cu: 2-15% Coercive force (IHC) is less than 2%.

This is not preferable because the coercive force (BHC) becomes extremely low, and if it exceeds 15%, the above coercive force tends to increase, but the saturation magnetization (4
π-ding, S),? 3. Since the residual magnetic flux density (Br) decreases significantly, which is not preferable, it is set in the range of 2 to 15%.

One or more of Nb, Ti, Zr, and V in a total of 0.1 to 10%. Nb, Ti, Zr, and V all have coercive forces (rHc, B
HC), and is an effective element for increasing Fe, C
In combination with the amount of u, it exhibits extremely high magnetic properties. However, if the total amount of one or more of these elements is less than 0.1%, such an effect cannot be clearly obtained, and if it exceeds 10%, the coercive force (rHc).

BHC) and residual magnetic flux density (Br) are lowered, which is not preferred in practice. Therefore, the total content of one or more of these elements was set in the range of 0.1 to 10%.

By adding one or two of Te, Se or a combination of these and S in a total of 0.01 to 2% Te, Se or a combination of these and S,
It is possible to sufficiently improve the cracking and chipping properties of the magnetic alloy, and in order to obtain such an effect, a total of 0.01%
It is necessary to do more than that. However, if it exceeds 2%, although the effect of improving the cracking and chipping properties described above can be obtained, the magnetic properties deteriorate significantly. Therefore, a total of 0.01 to 2% of one or both of Te and Se, or Te.

Combined addition of one or two types of Se and S to a total of 0.01
The range was set at ~2%.

Next, examples of the present invention will be described together with comparative examples.

An alloy having the composition shown in the table (sample numbers, odd numbers are examples, even numbers are comparative examples) was arc button melted in an argon atmosphere, and then coarsely ground to a 130 force mesh in an iron mortar. Next, the powder was pulverized to an average diameter of 4k using a jet mill using N-1. Subsequently, the obtained powder was placed in a magnetic field of 15 KOe and weighed at 1000 kg.
The molded body was compression molded at a pressure of /cm2, and the molded body was sintered under conditions of 1220'0Xlhr in an argon atmosphere. Thereafter, solution treatment was performed to maintain lhr at a temperature between 1100 and 1200°C suitable for each composition, followed by rapid cooling. Next, the sintered body was aged at 800°C for 20 hours, cooled in a furnace, and the resulting sintered body was carefully polished.
A 0+o+n prismatic magnet was produced.

Next, a Rattler tester (Powder Metallurgy Association standard:
JSPM Standard 4-69. r Powder and Powder Metallurgy” No. 16
(Vol. 5, No. 26, p. 26), select 5 magnets for each sample material, and as in the case of metal compacts, 87±
The wear loss in weight was measured after 5000 rotations at a rotation speed of 1 Orpm. In addition, the residual magnetic flux density (
Br), coercive force (BHC), maximum energy product (BH)
I also looked into fflax. These results are also shown in the table.

As is clear from the results shown in the table, one or two types of Te and Se M! Alternatively, in the test materials to which these elements and S were added in combination (No, odd numbers), the wear loss was much smaller than in the test materials to which these elements were not added (No, even numbers). It was confirmed that as a result of the increased strength, weight loss due to cracking and chipping at the edges was significantly reduced. Also, Te.

It was also confirmed that the addition of Se and S had no adverse effect on the magnetic properties. When the microstructure of the sintered magnet alloy according to this example was observed, it was found that the above-mentioned Nb was present at the grain boundaries.
, Ti, Zr, V and Te.

It is considered that a compound with Se and S is formed, which increases the strength of the grain boundaries, resulting in improved resistance to cracking and chipping.

As explained above, in the magnet alloy of the present invention, CO of the R2Co17-based magnet alloy is mixed with an appropriate amount of Fe, Cu,
Even when replacing with Nb, Ti, Zr, and V to further improve the magnetic % characteristics, the conventional R2Co1. Significant cracking compared to other magnet alloys.

It is possible to significantly improve the yield in the manufacturing process, and the R2C0,7-based magnet alloy has better magnetic properties than the RCo5-based magnet alloy, and the raw material cost is lower. This has the remarkable effect of making it possible to take full advantage of the advantages of

Patent applicant: Daido Steel Co., Ltd. Representative Patent Attorney Yutaka Shio

Claims (1)

[Claims] (1) Weight ratio: REM: 20-30%, Fe: 5-4
0%, Cu: 2-15%, and Nb. One or more of Ti, Zr, and V in total of 0.1 to 1
1. A rare earth cobalt-based magnet alloy, characterized in that it consists of 0%, roughly 0.01 to 2% in combination with one or both of Te, Se, or S, and the remainder substantially consisting of CO.