JPS602645A - Magnetostrictive bimetal - Google Patents

Abstract

PURPOSE:To obtain magnetostrictive bimetal having superior absolute stroke characteristics by providing a composition consisting of specified percentages of Co, Fe, Mn, Tb and Dy to an alloy having a positive coefft. of magnetostriction and a composition consisting of specified percentages of Co, Fe, Sm and Dy to an alloy having a negative coefft. of magnetostriction. CONSTITUTION:Magnetostrictive bimetal is composed of two kinds of alloys having positive and negative coeffts. of magnetostriction. The coefft. of magnetostriction is represented by the ratio of the quantity of strain/the strength of an applied magnetic field. A composition consisting of, by weight, 0.01-5% Co, 25-40% Fe, 1-15% Mn, 0.1-25% Tb and the balance essentially Dy is provided to said alloy having a positive coefft. of magnetostriction, and a composition consisting of, by weight, 5-40% Co, 2-35% Fe, 0.01-60% Sm and the balance essentially Dy is provided to said alloy having a negative coefft. of magnetostriction. Magnetostrictive bimetal having superior linearity, superior displacement history characteristics and stable characteristics is obtd.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to magnetostrictive bimetals.

More specifically, the present invention relates to a magnetostrictive bimetal made of Tb-Dy-re/Sm-Dy-Fe which has excellent bending properties, especially absolute stroke properties.

[Technical background of the invention and its problems] Recent improvements in machining accuracy in machine work (-) have been remarkable, and we are entering an era from microns to sub-microns.In electronic devices, etc. Nowadays, it is no secret that submicron machining accuracy is required, but as we enter the era of mechatronics, issues of ultra-fine machining and minute displacement control have become important not only in the field of electronic engineering but also in the field of mechanical engineering. Coupled with the development of optical information processing, optical recording equipment, etc., the need for minute displacement control elements will continue to increase.

Conventionally, thermal expansion type, piezoelectric type, electrostrictive type, and magnetostrictive type have been proposed as micro displacement control elements, but all of them have submicron precision and have excellent characteristics as micro displacement control elements. However, regarding the absolute stroke,
The current situation is that there is nothing that is completely satisfying.

[Objective of the Invention] The present invention provides a magnetostrictive bimetal with excellent absolute stroke characteristics, and more specifically, provides a magnetostrictive bimetal with excellent edge formability, displacement history characteristics, and stable characteristics. Therefore, it is an object of the present invention to significantly improve the stroke characteristics of a minute displacement control element, and to reduce its size and weight.

[Summary of the Invention] With the aim of realizing a small, high-performance magnetostrictive micro-displacement element, the present inventors investigated bimetalization, and as a result of intensive study of the constituent magnetostrictive members and bimetallic structure, the magnetostrictive coefficient ( , 3 = dε/dH, amount of strain/applied magnetic field) is composed of two types of alloys whose absolute value is l x IQ = Oe or more and whose signs are opposite, and △d (= Idl - d21 ) and the applied magnetic field. When we prototyped a magnetostrictive bimetal with a product △d・H of 2 x 10-' or more and evaluated its characteristics, we found that the absolute stroke amount, which was a drawback of conventional micro-displacement elements, was significantly improved. As a result, the present invention has been completed.

': That is, in the present invention, the absolute value of the magnetostriction coefficient (d) expressed as dε/dH (amount of strain/applied magnetic field) is 1×10−
608-1 or more, the magnetostrictive bimetal is composed of two types of alloys with opposite signs, and the product △d (= 1dl-d21) and the applied magnetic field, H, is 2 x 10-' or more. For details, see Cobal) (Co) 0.0
1-5 weight section, iron (Fe) 25-400% by weight +
Mangay (Mn) 1-15% by weight, Terbium (T)
b) An alloy with a positive magnetostriction coefficient (d) consisting of Q, 1 to 25% by weight and the balance substantially consisting of dysprosium (Dy) and Cobalt (Co) 5 to 40% by weight.

Iron (Fe) 2-35% by weight, samarium (Sm) 0
．． 01 "60% by weight and the balance is substantially composed of dysprosium (Dy) and has a negative magnetostriction coefficient (d),
The present invention will be described in detail below. First, in the magnetostrictive alloy that is the main element of the magnetostrictive bimetal of the present invention, terbium, dysprosium, and samarium belong to rare earth elements (lanthanides) and are different from 3d transition metals such as iron and nickel.
C has extremely large crystal anisotropy due to the strong orbital angular momentum of electrons, and is an essential component for obtaining excellent magnetostriction properties. At the same time, C is also the main component of the alloy that provides excellent toughness. shi1ka1. Ka, 8. fya, tsu4, ainio. Two 4,
Terbium alone, terbium-dysprosium alloy, and samarium-dysprosium alloy exhibit excellent magnetostriction properties at low temperatures, but do not exhibit magnetostriction at temperatures above room temperature, making it difficult to obtain satisfactory properties. It's impossible.

Iron, which is the main alloying (additional) element of the alloy according to the present invention,
Cobalt and manganese form a Laves type intermetallic compound with terbium, dysprosium, etc., and significantly improve magnetostriction properties in the temperature range above room temperature, resulting in satisfactory properties g1.

In the alloy C with a positive magnetostriction coefficient (d), the alloy component ranges of iron, manganese and cobalt are respectively 25% to 40% by weight of iron, 1% to 15% by weight of manganese, 0. The reason why cobalt is limited to 0.01% by weight or more and 5% by weight or less is that both iron and manganese are each 25% by weight.
Iron with less than 1% by weight and manganese with less than 1% by weight will not provide sufficient improvement in magnetostrictive properties, iron with more than 40% by weight will significantly deteriorate toughness and become brittle, and manganese with more than 15% by weight will not improve magnetostrictive properties. Characteristics deteriorate. Further, cobalt added to improve low magnetic field characteristics is limited to the above alloy component range C2 because if it exceeds 5% by weight, the magnetostrictive characteristics deteriorate.

Furthermore, what is the reason for limiting the range of alloying components of C terbium to 0°1% by weight or more and 25% by weight or less when it is only dysprosium rather than alloying f2 of terbium? The properties of iron, manganese and cobalt are further enhanced compared to
Although an excellent magnetostrictive alloy with a positive magnetostriction coefficient (d) was realized, no improvement in magnetostrictive properties could be obtained with less than 0.1% terbium, and no improvement in the magnetostrictive properties was achieved with more than 25% terbium. However, since a deterioration of the magnetostrictive properties was observed, alloy C with a negative zero-order C magnetostriction coefficient (d), which was limited to a range of 01v to 25 to 25, had alloy components of iron and cobalt. Range 2 weight each - over 35
The reason why it is limited to iron with a weight percentage of less than 5% and cobalt with a weight percentage of 5% or more and 40% by weight or less is that both iron and cobalt are 12% each.
If the iron content is less than 5% by weight, cobalt content less than 5% by weight will not provide sufficient improvement in magnetostrictive properties;
For cobalt that exceeds Keiichi, deterioration of magnetostrictive properties is recognized, so the above composition range (2) was limited.

Furthermore, the reason why the range of alloying components of samarium is limited to 0.01 weight fJ% or more and 60 weight needles or less is that due to the alloying of samarium, when only dysprosium is used, iron,
However, samarium with less than o and oi weights does not improve the negative magnetostrictive properties. Samarium is not noticeable and exceeds 60% by weight (in contrast, samarium is 0.01% by weight or more because deterioration of magnetostrictive properties is observed on the contrary).

The content was limited to 60% by weight or less.

The magnetostrictive bimetal of the present invention is composed of a magnetostrictive alloy having two types of magnetostrictive coefficients (d), positive and negative, as described above. For example, in the case of a displacement element for an automatic focusing mechanism, it is said that it is desirable to be able to obtain a sequential absolute stroke.

The bending characteristics of general I bimetals are expressed by the following formula, ax
(Displacement amount) = Yu!・Δd−H 4χ (where 1 is the length of the plate), ” is the thickness of the plate.Δdl is the difference in the magnetostriction coefficients of the magnetostrictive alloys that make up the bimetal (1dl−d21) and H is the applied magnetic field (Oe).) As the absolute stroke (aX), the fin order e.g. Sx
To obtain = 1 m (J = 30 m,
Under the condition of i = 0.2, Δd - H = 2.96
10"".

In this manner, the magnetostriction coefficient (d) of the magnetostrictive bimetal component of the present invention and the curvature coefficient (Δd, T() of the bimetal) are regulated in consideration of practical conditions.

Next, the method for manufacturing the magnetostrictive bar and Imetal of the present invention will be exemplified.

The magnetostrictive bimetal of the present invention is manufactured by preparing an alloy material having the above composition having magnetostrictive coefficients of positive and negative signs by a well-known method C2 in a vacuum, an inert gas, or a source gas atmosphere at a temperature above the melting point. After melting in step C, casting is performed to obtain cast ingots of magnetostrictive alloy having two types of signs, positive and negative.

After cutting plates of appropriate dimensions from the obtained ingot, CoBDy4 was placed between these plates.

Using filler material C2, powder having a eutectic alloy composition of Dy, Fe, and Co such as Co4Dy7 was heated at 800°C to 1000°C.
By performing diffusion bonding between C'''-, a magnetostrictive bimetal is obtained.

The magnetostrictive bimetal thus obtained has a curvature coefficient (
△d, H) is extremely large at 2 x 10-4 or more, making it possible to make an absolute stroke of H order, and because it is an alloy, it has excellent fatigue strength and impact resistance C1, so it is especially suitable for large Driving bimetal for micro-displacement element with high output and high load (2) C suitable for use [Embodiments of the invention] The magnetostrictive bimetal of the present invention will be described in detail below with reference to embodiments.

Example I Co 1,2 weight 8%, Mn 7.3 weight i%, F
e 28.1ii%.

An alloy material consisting of 13% by weight of Tb and the balance being Dy was melted in a vacuum induction melting furnace and then cast to obtain a cast ingot.

Next, from this cast ingot, a short fence-shaped sample of 150 mm thick x 3 mm wide x 30 M1 long was cut out, and the magnetostriction coefficient (d
) A positive plate-shaped magnetostrictive member was obtained.

In addition, before cutting out the above-mentioned short fence-shaped sample, the ingot was
It is desirable to homogenize at ℃.

The above-mentioned plate-shaped magnetostrictive member and a thin nickel plate having a negative magnetostriction coefficient (d) with a thickness of 100 μm, a width of 3 m, and a length of 30 μm are stacked,
After inserting a powder filler material having an intermetallic compound composition of H2CoBDy4 at the interface, a diffusion treatment was performed at 800° C. for 2 hours under a reduced argon pressure of 100 Torr to join the two members to obtain a bimetal.

The magnetostrictive coefficient (d) of each of the magnetostrictive materials constituting this bimetal is d
1 = + 5xto Oe, Nt is d2 = 0.
33 x 1O-60e-1 and the applied magnetic field H=1
000e, Δd (= ld
The displacement (stroke) characteristic of the magnetostrictive bimetal is n,
Sx (stroke) at an applied magnetic field of 1000e
= 1.35 m and the curvature characteristic is 13.5 pm-
Example 2 Co 22.0% by weight, Fe 9.50 M%
, Sm 49.3ifN and the balance was Dy, and the alloy material was melted in a vacuum induction melting furnace and then cast to obtain a cast ingot.

Next, 150 μm thick x 3 from this cast ingot
A short shelf-shaped sample of mJ+width×30 length was cut out to obtain a plate-shaped magnetostrictive member with a negative magnetostriction coefficient (d).

In addition, the IZ ingot 800 before cutting out the short fence-shaped sample mentioned above.
It is desirable to homogenize at ℃.

Fe-Co-U alloy (Per
Co
After inserting the powder filler material having a B11y4 intermetallic compound composition, it was heated at 800°C under a reduced pressure of 100 Torr argon pressure.
A two-hour diffusion treatment was performed, and the five members were joined to obtain a bimetal.

The magnetostriction coefficient (d) of each of the magnetostrictive members constituting the present bimetal is d2:2 for the Sm-Dy-Fe-Co alloy.
5 XIQ-60e-”, re-Co-V is di
= + 0.7
(= 1dl-d21) x The value of H is 3 x 10
-' was.

The displacement (stroke) characteristics of non-magnetostrictive bimetals are as follows:
1000e applied magnetic field 22, SX (stroke)
= 0.8 ms, and the curve characteristic is 3,92
It was m0e-1.

Example 3 CoQ, 5% by weight, Mn 6.2% by weight, Fe
29.0% by weight.

An alloy material consisting of 12.5% by weight of Tb and DY was melted in a vacuum induction melting furnace and then cast to obtain a cast ingot.
A short shelf-shaped sample having a width of 30+u in length was cut out to obtain a plate-shaped magnetostrictive member with a positive magnetostriction coefficient (d).

i f4 Co 21.5 %ri % + P”e
20.3:1:111]V2% + Sm12-
Similarly, an alloy material consisting of triple fj% and the balance Dy
Two-vacuum pride melt f'! After casting, a cast ingot was obtained. Next, the thickness of the cast ingot was 100 μm.
A short shelf-shaped sample with a length of width X30*a was cut out to obtain a plate-shaped magnetostrictive member with a negative magnetostriction coefficient (d).

In addition, the C nine ingot before cutting out the short fence-shaped sample was 800 mm.
It is desirable to homogenize at ℃.

After superimposing the plate-shaped magnetostrictive members with positive and negative signs on the upper He(M magnetostrictive coefficient (d) and inserting a powder filler material having CoBTJy4 intermetallic compound introduction on the interface, 1QQTo
rr Diffusion treatment was performed at 800°C for 2 hours under reduced pressure of argon, and both members were bonded to obtain a bimetallic structure. Dy-Fe-Mn-Co alloy is dl
= +6.2 X 100e, Sm-Dy-Fe
-Co alloy has d2=-3, IX 1O-60e-1, and under the applied magnetic field H=lQQOe, the value of Δd eldx-d21 ) x H of this magnetostrictive bimetal is 9
It was 10-'.

The displacement (stroke) characteristics of non-magnetostrictive bimetals are as follows:
At 1000e applied magnetic field, aX (stroke) = 3
u, and the curvature property was 30 μm0e−1.

Comparative Example 1 A clad material of the Fe-Co-V alloy with a positive magnetostriction coefficient (d) and nickel with a negative magnetostriction coefficient (d) was produced by rolling, and then a short shelf shape of 3 m width x 30 lengths was produced. A sample was cut out to obtain a magnetostrictive bimetal. The thickness of the obtained bimetal was 2.00 μm.

The magnetostriction coefficient (d) of each of the magnetostrictive members constituting this bimetal is dl = + Q,
7 X100e, and nickel is d2 = -0,
33x 100e-1 and the applied magnetic field H= l QQ
Under Oe, the magnetostrictive bimetal's △' (= 1dl
-d21) XH value was 1'tlX10-4.

The displacement (stroke) characteristics of this magnetostrictive bimetal are as follows:
1000e applied magnetic field C2, SX (stroke)
= 0.34 wx, and the curvature characteristic is 3μ
It was m0e-'.

[Effects of the Invention] As is clear from the above explanation, the magnetostrictive bimetal of the present invention has excellent absolute stroke characteristics, excellent linearity and displacement history characteristics, and has excellent fatigue strength and impact resistance. Because of its excellent properties, its industrial value is extremely high for applications such as micro-displacement elements for automatic focusing mechanisms that require high loads and absolute strokes on the order of ribs.

Agent: Patent attorney Noriyuki Chika (and 1 other person) 239-

Claims (1)

[Scope of Claims] (1) The magnetostrictive coefficient (d) expressed by dε/dH (amount of strain/applied magnetic field) is composed of two types of alloys in which the signs of the magnetostrictive coefficient (d) are opposite in positive and negative, and one of the magnetostrictive coefficients (d ) is positive alloy is cobalt (Co) 0.01 = 5% by weight, iron (F'e)
Magnetostrictive bimetal (2) characterized in that it consists of 25 to 40% by weight, manganese (Mn) 1 to 15% by weight, terbium (Tb) Q, 1 to 25% by weight, and the balance substantially [-dysprosium (Dy)] It is composed of two types of alloys whose magnetostrictive coefficients (d) have opposite signs, positive and negative, and the alloys whose magnetostrictive coefficients (d) are negative are cobalt (Co) s ~ 40% by weight and iron (Fe) 2 ~ 35%.
Magnetostrictive bimetal (8) characterized in that M amount is 1, samarium (8 m) 0.01 to 60% by weight, and the remainder is substantially [dysprosium (Dy)] Cobalt (Co) 0.01 = 5% by weight,
Iron (Fe) 25-40% by weight, Mangay (Mn) 1
-15% by weight. Terbium (Tb) Q, 1 to 25% by weight and the balance being substantially g: Magnetostrictive coefficient consisting of disbrosium (Dy) (
d) positive alloy and cobal) (Co) 5 to 40% by weight
. Iron (Fe) 2, +35% by weight, samarium (
A magnetostrictive bimetal characterized in that the magnetostrictive coefficient (d) is composed of an alloy having an angle of 0.01 to 60% by weight and the remainder being substantially f-dysprosium (Dy).