JPS621841A - Amorphous alloy having low thermal expandability - Google Patents

Abstract

PURPOSE:To obtain an amorphous alloy having a very low coefft. of thermal expansion in a wide temp. range by providing a composition consisting of a prescribed amount in total of regulated amounts of Zr and P and/or B and the balance essentially Fe. CONSTITUTION:This amorphous alloy having a low coefft. of thermal expansion consists of, by atom, >=10% in total of 6-15% Zr and <8% P and/or B and the balance essentially Fe. The amorphous alloy has -15X10<-4>-+8X10<-6>/ deg.C coefft. of thermal expansion and solves problems peculiar to a known amorphous Fe-B alloy as a binder. It also has high crystallization and brittle temps. and higher heat resistance than the Fe-B alloy. The tensile strength and hardness are >=5 times and >=4 times as high as those of a crystalline Fe-Ni alloy, 'IN VAR(R)', respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an amorphous alloy containing an iron group element and zirconium as basic components and having a low coefficient of thermal expansion.

Conventional alloys with low expansion coefficients include crystalline Invar (Ni approx. 36wtZ, Fe approx. 64wtZ), Super Invar (Ni approx. 32wtZ, Co approx. 5wtZ,
Fe approx. 63wt2) or stainless steel invar (
Co approx. 54wtLCr approx. 9.5wtZ, Fe approx. 3
6.5wtX) is mainly used. These alloys have a large positive spontaneous bulk magnetostriction at temperatures below the Curie temperature (hereinafter referred to as Tc), so their thermal expansion coefficients decrease to a fraction of that of ordinary metals. We are using.

However, these crystalline invar alloys have the disadvantage of low mechanical strength, particularly low tensile strength and hardness (in order to improve these, it is necessary to increase the processing rate by cold working). This cold working has disadvantages such as the so-called Δα effect, which causes anisotropy in the coefficient of thermal expansion, and this remains an unresolved problem.

In addition, conventional crystalline Invar alloys undergo phase transformation up to the temperature of liquid nitrogen, so they do not exhibit Invar characteristics in low-temperature regions. On the other hand, since Tc is relatively low, it has the disadvantage that it does not exhibit good invar characteristics at high temperatures of 100° C. or higher.

In addition to the above-mentioned invar-based alloys, alloys with low expansion coefficients include Fe-Pd alloys, Fe-Pt alloys, and Cr-based alloys, all of which exhibit excellent properties in terms of expansion coefficient. The former is very expensive because it contains precious metals as its main component, and the latter has the disadvantage of poor workability.

In general, low expansion coefficient alloys are mainly used for measurement materials, electromagnetic materials,
Existing crystalline invar alloys are often used in the form of thin wires or thin sheets as materials for control equipment, etc. Although they are relatively malleable, they require multiple stages of processing and heat treatment to transform them from ingots to thin sheets of the required thickness. This requires complicated manufacturing processes, and the fuel and electricity costs required for these processes are also large.

On the other hand, "Low thermal expansion coefficient amorphous alloy and method for producing the same" invented by one of the present inventors together with other inventors and disclosed in JP-A-53-147604 contains Fe and B as main components. There is a description that an amorphous Invar alloy can solve the problems of the above-mentioned crystalline Invar alloy. However, the Fe-82 element amorphous alloy has poor corrosion resistance and heat resistance.
Revised these properties.

When elements other than Fe and B are added to improve the performance, there is a drawback that the Invar characteristics rapidly deteriorate.

Incidentally, the Invar characteristics of a low thermal expansion coefficient alloy, that is, an Invar alloy, are thought to be due to the large spontaneous volume magnetostriction accompanying the generation of magnetization of the alloy. Therefore, not all amorphous alloys have Invar properties, and certain physical requirements are required for an amorphous alloy to have Invar properties. That is, the composition of the alloy needs to be in a composition range that can form an amorphous alloy and at the same time has a large spontaneous bulk magnetostriction.

However, the alloy described in JP-A No. 53-147604 has the following information: ``B is necessary for making the alloy structure amorphous. It is an element that contributes to an increase in strength, but when it is less than 8% or more than 30% in atomic %, it is difficult to make it amorphous and becomes brittle, and the coefficient of thermal expansion is +8X10-' or more. Otherwise, it becomes less than -3X10-'' and is not suitable for Invar material, so it is necessary to make it 8 to 30 atomic %. '', it has been revealed that if B is less than 8%, it is difficult to make it amorphous and it is not suitable for Invar materials.

On the other hand, the present inventors and other inventors previously discovered that Zr is effective as an amorphous element,
No. 3838 discloses an invention of "an amorphous alloy containing an iron group element and Zr".

Further research has shown that some Fe-Zr amorphous alloys have large spontaneous volume magnetostrictions, and that alloys with less than 8% B and/or P added to these alloys have excellent invar properties. The present invention was conceived based on the new finding that the present invention is an excellent invar alloy that can solve the problems of the crystalline invar alloy and the Fe-B amorphous invar alloy described above.

The present invention exhibits extremely low thermal expansion over a wide temperature range compared to conventional crystalline-Invar alloys. The purpose of the present invention is to provide an amorphous alloy that has a high coefficient of
An amorphous alloy consisting of 6 to 15% and less than 8% of B and/or P and the balance Fe, or a part of the Fe in the above alloy is replaced with one or two of Co and Ni. The present invention relates to an amorphous alloy having a low coefficient of thermal expansion and having an amorphous alloy as its basic composition.

Next, the present invention will be explained in detail.

Ordinary solid metals and alloys are in a crystalline state, but they are cooled much more rapidly than liquids (the cooling rate depends on the composition of the alloy, but approximately 10
If the metal is ultra-quenched from the gas phase using a sputtering method or the like, a solid with an amorphous structure that does not have a periodic atomic arrangement similar to a liquid can be obtained; It is called a pure metal or amorphous metal.

In general, this type of metal is an alloy consisting of two or more types of elements, usually a combination of both transition metal elements and metalloid elements (the amount of metalloids is approximately 10 to 30 at%), or two types of metals with different atomic radii. Or a combination of three or more transition metal elements.

The Fe-B-based amorphous Invar alloy contains 8 to 30 at % of B, which is one of the semimetals, as an amorphous forming element, and the former, that is, the amorphous consisting of a combination of a transition metal element and a semimetal element. It is a type of quality alloy.

On the other hand, the present invention is essentially the latter, that is, an amorphous alloy consisting of an iron group element, which is a transition metal, and zirconium. The present invention has been completed based on the new finding that an amorphous alloy containing the following has an extremely low coefficient of thermal expansion over an extremely wide temperature range.

Table 1 shows the thermal expansion coefficients and hardnesses of the amorphous alloy of the present invention and several examples of already known Fe-B amorphous alloys and crystalline Invar alloys as comparative examples.

In Table 1, alloys Nos. 1 to 120 are amorphous alloys with low thermal expansion coefficients of the present invention, and Nos. 21 to 25 are comparative examples. Of the comparative examples, patients 21 to 23 are Fe-
The alloy is a B-based amorphous alloy, and the alloys 24 and 25 are conventional crystalline invar alloys.

Among the alloys of the present invention, alloys that do not contain Ni or Co (Table 1
1kL1~4. In cases 8 to 11), the Curie temperature Tc is relatively low at 130°C to +80°C, so the coefficient of thermal expansion at high temperatures is large, but it is small in the temperature range of 100°C to +50°C, especially -100°C to 0°C. It has a negative value at °C.

Also, alloys containing Go and Ni (Table 1 Kan 5-7. 12-
20) has a low coefficient of thermal expansion over a wide temperature range of -100°C to +300°C, for example, the alloy of the present invention of No. 7! l1l
Comparing 124 crystalline Fe-Ni Invar alloys,
The absolute value of the coefficient of thermal expansion of the alloy No. 7 is around room temperature, rlh
It was found that the Fe alloy of No. 21 has excellent invar characteristics, which is less than 175 and its value hardly changes over a wide temperature range.
-B-based amorphous alloy, it can be seen that it has the same or better Invar properties.

In addition, the Fe-82 element amorphous alloy has low corrosion resistance or heat resistance, and these properties can be improved by adding a third element other than Fe and B.
It has the disadvantage that the coefficient of thermal expansion increases rapidly like o alloys. -5 Inventive alloys are N18-11 and N111
As seen in 2-20, iron group elements and B, P and Z
It can be seen that even when 5 to 10% of elements other than r are added, the coefficient of thermal expansion of the alloy hardly changes. This is also another great feature of the alloy of the present invention.

Further, as shown in alloy No. 6 in Table 1, if necessary, the amorphous alloy of the present invention obtained by ultra-quenching from the molten state is further annealed at a temperature below the crystallization temperature, and then rapidly or slowly cooled. The amorphous alloy of the present invention having a low coefficient of expansion can also be obtained by this method. In this case, it is advantageous for the annealing atmosphere to be non-oxidizing or vacuum.

The degree of crystallization of the alloy of the present invention varies depending on its component composition, but it is within the range of 400 to 600°C, and when annealed at a temperature higher than the crystallization temperature, it crystallizes and the coefficient of thermal expansion increases rapidly. do. The annealing and the subsequent rapid cooling or slow cooling have the effect of removing distortion during rapid solidification and stabilizing thermal expansion characteristics.
00℃ to below the crystallization temperature for 1 minute to 500℃.
The alloy of the present invention having even better Invar properties can be obtained by holding for a longer time.

Next, the alloy of the present invention will be explained based on research data. All the alloys explained below were made into amorphous material by ultra-quenching from the molten state and solidifying. It is a sample.

The effect of B in the composition of the alloy of the present invention will be explained.

Figure 2 shows the temperature range from about -200°C to +2°C for the alloy according to the present invention and similar alloys with a constant ZrtM degree of 10 atomic %.
FIG. 3 is a diagram showing the results of measuring the coefficient of thermal expansion of a ribbon while heating it from 00 to 400°C. The alloy shown in parentheses in the figure is an amorphous invar alloy similar to the alloy of the present invention. For example, Fe. Zr, o and Fee which is the alloy of the present invention
Comparing the thermal expansion curves of s Bs ZrIo alloy, B
It can be seen that by adding , the Curie temperature increases, the temperature change in the coefficient of thermal expansion becomes more gradual, and the temperature range exhibiting Invar characteristics expands.

Moreover, the Feyz Cots Zr+o alloy and the Feyz Cots Zr+o alloy of the present invention
&11Coat Bs ZrIo alloy.

It can be seen that although the relative Becury temperature is slightly lower than that of the comparative alloy, the temperature change in the coefficient of thermal expansion is still more gradual.

Figure 3 shows the effect of B on the magnetization (σ8a), Curie temperature (Tc) and crystallization temperature (Tx) at room temperature of an alloy in which Zr is kept constant at 10 atomic % and some of Fe is replaced with B. Showing the influence of 14 degrees. It can be seen that even at a B concentration of less than 8% in the alloy of the present invention, it has the effect of increasing magnetization and Curie temperature as well as improving crystallization temperature. As shown in FIG. 2, as the Curie temperature increases, the temperature range showing the invar characteristics of Fe-Zr expands to a higher temperature side. Furthermore, an increase in the crystallization temperature has the effect of facilitating heat treatment for further stabilizing the Invar characteristics.

Furthermore, (Fe6.1lco+1.2)90 Zrro
Based on amorphous alloy, some of Fe and Co are replaced with B or P.
(FeO, 1lCOO, ri90-x
Mx Zr+.

The relationship between the thermal expansion coefficient at room temperature and the concentration of each additive element for various alloys expressed by the formula (M2R, P) was measured, and the results are shown in FIG. The coefficient of thermal expansion varies depending on each additive element, but in any case, the value of the coefficient of thermal expansion is between -13X10-6 and +8X1 within the concentration range of the alloy of the present invention.
In particular, in the case of B, the thermal expansion coefficient at room temperature hardly changes even if about 8% is added, so other properties such as heat resistance, oxidation resistance, etc. It is extremely advantageous for improving

Next, the reason for limiting the composition of the alloy of the present invention will be described.

If Zr is less than 6%, it is difficult to make it amorphous even if it is ultra-quenched, and if it is more than 15%, the crystallization temperature will decrease and it will be difficult to obtain a stable amorphous alloy, so it should be within the range of 6 to 15%. Further, when Zr is in the range of 9 to 13%, a more stable amorphous alloy with a small coefficient of thermal expansion can be obtained.

P and B facilitate the amorphization of the alloy and have the effect of increasing the Curie temperature of the Fc, -Zr binary amorphous alloy, but if they are added in an amount of 8% or more, the coefficient of thermal expansion near room temperature becomes insufficient. If it becomes larger than axio-6, or the alloy becomes easily brittle, it needs to be less than 8%.

Furthermore, in order to stably obtain an amorphous alloy, it is necessary that the total amount of Zr and at least one selected from P and H be 10% or more.

By adding up to about 40% of Ni and Co, the coefficient of thermal expansion can be adjusted to a range of 113 x 10-15 x 1.0-'.Moreover, it has the effect of increasing the Curie temperature, so it has a low coefficient of thermal expansion. The temperature range can be expanded. However, if Co or Ni is added in excess of 40%, the thermal expansion coefficient will increase by more than +8 x 10-', so it must be kept below 40%, and if it is within the range of 8 to 30%, the Thermal expansion coefficient is 113X10-”~+
A value as small as 4×10-h can be obtained.

The alloy according to claim 2 or 4 of the present invention includes: (a) Be, Al, Si, Ge, Sn, Sb, In
has the effect of facilitating the amorphization of the alloy and increasing the Tc of the Fe-Zr binary amorphous alloy, but Be, Al
, Si.

When Ge, Sn, Sb, and In are added in an amount exceeding 25%, the coefficient of thermal expansion near room temperature becomes larger than +8×10 −6 , so it is necessary to limit the amount to 25% or less. Also N
For alloys that simultaneously contain i and Co, the elements in group (a) above have the effect of facilitating the amorphization of the alloy and expanding the temperature range in which it has a constant low coefficient of thermal expansion, but if it exceeds 25%, Since the coefficient of thermal expansion near room temperature increases significantly, it needs to be 25% or less, preferably 15% or less, and more preferably 10% or less.

CrM, an element of groups V1++ and V of the periodic table
o, W, v, Nb, and Ta have the effect of raising the crystallization temperature, improving the heat resistance of the alloy, and at the same time improving the corrosion resistance, but if it exceeds 20%, it becomes difficult to make it amorphous, and the coefficient of thermal expansion decreases. increases, so it must be kept at 20% or less, preferably 15% or less, and more preferably 10%.
The following is good.

Mn and Cu improve the corrosion resistance of the alloy, but if it exceeds 15%, it also increases the coefficient of thermal expansion, so 15%
It needs to be below, preferably 10% or below.

Tc, Ru, Rh, Pd, Pt, Os,
All of Ir are elements that tend to make the alloy amorphous, but if at least one selected from these exceeds 15%, the coefficient of thermal expansion will increase, so it is necessary to keep it below 15%. , preferably 10% or less.

Ti, Hf, Sc, Y, and lanthanide elements are all 10
% or less has the effect of promoting the amorphization of the alloy, but if it exceeds 10%, the alloy becomes susceptible to oxidation, so it needs to be 10% or less, preferably 5% or less.

Furthermore, since the addition of elements of groups (a) to (e) promotes the amorphization of the alloy, a stable amorphous alloy can be obtained with a Zr content in the range of 6 to 15%, but - 13X10-
In order to obtain a thermal expansion coefficient of 15 x 10-6, the total of at least one selected from P and B and at least one selected from the groups (a) to (e) must be 25
% or less, and the total of these elements and Zr needs to be within the range of 10 to 35%.

By adding up to about 40% of Ni and Co, the coefficient of thermal expansion can be adjusted within the range of -13X10-6 to +8X10-', and since it has the effect of increasing the Curie temperature, it has a low coefficient of thermal expansion. The temperature range can be expanded. However, if Co or Ni is added in excess of 40%, the thermal expansion coefficient will increase by more than +8 113X10-'~+
A value as small as 4×10−′ can be obtained.

Next, the present invention will be explained by examples.

Example 1 High-voltage power transmission lines thermally expand due to rising temperatures or Joule heat due to an increase in the amount of power transmitted, resulting in an increase in sag, making it impossible to maintain an appropriate distance from the ground to the transmission line, and causing damage to steel towers. Since the load applied to the tower also changes, there are problems such as the need to rebuild the tower itself in some cases.

Therefore, recently, low-sag, heat-resistant aluminum alloy stranded wires that use an invar alloy with a small coefficient of thermal expansion as the steel core of power transmission lines have become known. Because the sag does not increase much even when the temperature rises due to Joule heat, it is possible to carry about twice as much current as an aluminum alloy stranded wire with the same cross-sectional area using a normal steel core.

However, the conventional Fe-Ni invar alloy has a low tensile strength of about 45 kg/mo+", and has the disadvantage that it requires a steel core with a larger cross-sectional area than ordinary steel core materials in order to withstand the load of large-diameter power transmission lines. Moreover, at 230° C., which is the maximum operating temperature of the power transmission line, the coefficient of thermal expansion of the Fe-Ni Invar alloy is relatively large, ranging from 4 to 6XIO-'.

On the other hand, some of the alloys of the present invention have a coefficient of thermal expansion of 1.0×10-
There are many products that exhibit extremely excellent invar characteristics, which are as small as b or less and hardly change over a wide temperature range of -100°C to +300°C.
Tensile strength is 200 kg/mm2 to 250 kg/mm”
It exhibits excellent mechanical properties that are 3 to 5 times higher than those of conventional Fe-Ni invar alloys.

Some examples are shown in Table 2.

In the same table, the embrittlement temperature is the temperature at which rupture occurs when a ribbon-shaped specimen of an amorphous alloy is heated at various temperatures for 100 minutes, and after being slowly cooled, the ribbon-shaped specimen is bent until it is completely attached. This means that the higher the embrittlement temperature, the better the heat resistance of the amorphous alloy.

As can be seen from this table, the alloy of the present invention has excellent invar properties, high tensile strength, and superior heat resistance compared to Fe-B amorphous alloys, making it ideal as a steel core material for power transmission lines. I understand that.

As can be seen from the above research data and examples of the alloy of the present invention, the temperature range in which a low coefficient of thermal expansion can be obtained in the amorphous alloy of the present invention is from -195°C to about 300°C (up to 400°C depending on the composition). However, with current Invar alloys, the temperature range in which a low coefficient of thermal expansion can be obtained is approximately 100°C, centered around room temperature, whereas the temperature range of the amorphous alloy of the present invention is extremely wide. Alloys with a coefficient of thermal expansion as small as -13x10-15x10-6 in such a wide temperature range are completely unknown, except for the Fe-B amorphous alloy for which one of the inventors has already applied for a patent. It wasn't.

The amorphous alloy of the present invention also has a high crystallization temperature and a high embrittlement temperature, and has excellent heat resistance compared to conventionally known Fe-B-based amorphous alloys.

Furthermore, the tensile strength and hardness are more than 5 times and 4 times higher than crystalline Fe-Ni invar alloys, respectively, making it suitable for applications that require mechanical strength, and the above properties are maintained even when processed or subjected to tension. It is constant and almost unchanging, ie insensitive to external stresses. Furthermore, the alloy of the present invention becomes amorphous during manufacturing, so that at least 104
It is necessary to perform ultra-rapid cooling at a cooling rate of ℃/second or more, and therefore, since it can be easily obtained in the form of a thin plate or film, it is easy to process such as cutting and punching, which makes it difficult to process conventional methods with complicated manufacturing processes. This is extremely advantageous compared to crystalline invar alloys.

The thermal expansion properties of the rapidly cooled amorphous alloy of the present invention are further improved by low-temperature annealing, and its properties are stabilized against repeated heating and cooling, and it has a thermal expansion coefficient of 0XIO-6. Obtainable.

As described above, the alloy of the present invention can be very suitably used as a steel core material for power transmission lines, an electromagnetic material, a precision measurement material, a control equipment material, and the like.

[Brief explanation of drawings]

Figures 1 (a) and (b) are diagrams schematically showing an apparatus for the liquid quenching method, which is one of the methods for producing the alloy of the present invention, and Figure 2 shows several types of the alloy of the present invention and comparative alloys. Figure 3 shows the respective thermal expansion curves for Feqo-x Bx
Figure 4 shows the influence of B concentration on the magnetization, Curie temperature and crystallization temperature of Zr+O alloy.
It is a figure which shows the relationship between the thermal expansion coefficient of an amorphous alloy in which P or B is added to an o-Zr ternary amorphous alloy and the amount of the added element. 1. Molten metal, 2. Amorphous ribbon. 3. Cooling drum, 4. Cooling roll. Patent applicant Kendo Masumoto Sumitomo Special Metals Co., Ltd. agent Patent attorney Mura 1) Politics Figure 1 (a) <b> Figure 2 ↓ Hiroshi (C) Figure 3 0 2 4 6 B TO'
12 14 168 dark fake, X (azel・)

Claims (1)

[Scope of Claims] 1. Contains 6 to 15% of Zr in atomic % and less than 8% of at least one of P and B, and the total of the Zr and at least one of P and B is 10% or more. The remainder essentially consists of Fe, and the coefficient of thermal expansion is -15×10^-^6~+
An amorphous alloy with a low coefficient of thermal expansion in the range of 8x10^-^6. 2. Zr6 to 15% in atomic %, less than 8% of at least one of P and B, the following (a), (b), (c), (d)
, at least one selected from the group (e), provided that at least one of P, B and the following (a)
, (b), (c), (d), and (e), the total of which is 25% or less, and the total with Zr is within the range of 10 to 35%. , the remainder essentially consists of Fe, and the coefficient of thermal expansion is -15×10^-^
An amorphous alloy having a low coefficient of thermal expansion in the range of 6 to +8 x 10^-^6. (a) Any one or more selected from Be, Al, Si, Ge, Sn, Sb, In and 25% or less (b) Selected from Cr, Mo, W, V, Nb, Ta (c) Any one or two selected from Mn, Cu, 15% or less (d) Tc, Ru, Rh, Pd, Pt, Os, Ir Any one or more selected from the following, up to 15% (e) Ti, Hf, Sc, Y, and any one or more selected from the lanthanide elements, up to 10% 3, at % Contains 6 to 15% Zr, 40% or less of at least one of Ni and Co, and less than 8% of at least one of P and B, and the total of the Zr and at least one of P and B is 10 % or more, the remainder substantially consists of Fe, and the coefficient of thermal expansion is -15 x 10^-^6 to +4 x 1
The alloy according to claim 2, which is within the range of 0^-^6. 4. Zr6 to 15% in atomic %, at least 40% of any one of Ni and Co, less than 8% of at least one of P and B, the following (a), (b), (c), ( Containing at least one selected from the group d) and (e),
However, the total of at least one of P and B and at least one selected from the following groups (a), (b), (c), (d), and (e) is 25% or less Furthermore, the total of the above groups P and B, groups (a) to (e), and Zr is 10
~35%, with the remainder essentially consisting of Fe;
Thermal expansion coefficient is -15 x 10^-^6 to +8 x 10^-^
An amorphous alloy having a low coefficient of thermal expansion within the range of 6. (a) Any one or more selected from Be, Al, Si, Ge, Sn, Sb, In and 25% or less (b) Selected from Cr, Mo, W, V, Nb, Ta (c) Any one or two selected from Mn, Cu, 15% or less (d) Tc, Ru, Rh, Pt, Pd, Os, Ir Any one or more selected from the following, up to 15% (e) One or more selected from the group consisting of Ti, Hf, Sc, Y, and lanthanide elements, up to 10%