JPH10146633A - Production of twisted wire member consisting of nickel-titanium shape memory alloy fine wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a twisted wire consisting of a Ni-Ti shape memory alloy fine wire having reduced surface oxidation and good quality by simultaneously subjecting plural wires to drawing, annealing, forming and shape memorizing treatment. SOLUTION: The twisted wire member consisting of a Ni-Ti shape memory alloy fine wire is produced so that plural wires of a Ni-Ti shape memory alloy wire subjected to a straight line memorizing treatment beforehand, while maintaining to a temp. state higher than the transformation temp. of a wire stock, is covered with a metal sheathing material to form a composite wire stock, successively, by repeating cold reducing and annealing for the composite wire stock, a composite drawn wire of a prescribed size is produced, by twisting the composite drawn wire and forming to a prescribed length and shape, a twisted composite drawn wire is produced, successively, after subjecting to memorizing treatment thereon, the sheathing material is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a stranded wire member made of a Ni-Ti based shape memory alloy thin wire, and more specifically, to a method of inserting a plurality of wires into an exterior material to form a composite element. A wire is formed by repeating wire drawing and annealing to form a composite wire, twisted, formed into a predetermined length and shape, subjected to shape memory treatment, and then the exterior material is formed. With this manufacturing method, a stranded wire member made of a Ni-Ti-based shape memory alloy thin wire with less oxidation on the surface can be supplied at a low cost.

[0002]

2. Description of the Related Art In recent years, Ni-Ti based shape memory alloy wires (for example, thin wires having an outer diameter of 100 to 500 μm) have been developed by utilizing their shape memory characteristics or superelastic characteristics to guide spring wires, guide wires such as electric conduits, and the like. It is used as the core material of brassieres. Conventionally, these wires are mostly used as single wires, but in terms of further softness or flexibility, a plurality of fine wires (for example, a thin wire having an outer diameter of 100 to 500 μm) are used as a stranded wire. It is preferable to supply a stranded wire member. However, in general, Ni-T
The i-type shape memory alloy is poor in workability, particularly difficult to work in cold working, and the cold working rate (area reduction rate) requiring annealing at the time of cold drawing is as low as 30% or less. Therefore, in the drawing process, while repeating many annealing and drawing,
Drawing is performed at a processing rate of about 8 to 15% per pass to obtain a wire having a predetermined diameter. Therefore, it is difficult to mass-produce wires, especially fine wires, and there is a problem that it is expensive.

Further, when the number of times of annealing increases, the oxide film on the surface of the wire becomes thicker, and the surface is easily damaged, which causes disconnection. Therefore, several pickling steps are required on the way. As described above, the fine wires of the Ni-Ti alloy have poor workability, yield, and the like, and it has been difficult to manufacture inexpensive and high-quality Ni-Ti-based shape memory alloy fine wires. Further, the production of the above-mentioned twisted wire member requires a step of twisting a plurality of fine wires, and there is a problem that the production becomes more expensive.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems. Specifically, in the drawing step, oxidation of a wire surface caused by annealing is prevented, and An object of the present invention is to find a method for producing a high-quality fine wire that is inexpensive and less oxidized by simultaneously drawing a plurality of fine wires. Another object of the present invention is to find a specific method for producing a large number of fine wires that matches the characteristics of a Ni—Ti alloy and is suitable for the above-mentioned production purpose. Further, another object of the present invention is to find a manufacturing method for inexpensively manufacturing a stranded member made of a plurality of fine wires.

[0005]

According to a first aspect of the present invention, a plurality of Ni-Ti based shape memory alloy wires which have been subjected to a straight line storage process are provided. While maintaining the temperature higher than the transformation point of the wire, the wire is covered with a metal sheathing material to form a composite wire, and then the composite wire is repeatedly subjected to cold drawing and annealing to form a composite wire. After being drawn, the composite wire was subjected to a twisting process, and then formed into a predetermined length and shape to obtain a twisted composite wire drawing member, which was then subjected to shape memory processing. Thereafter, a method of manufacturing a stranded wire member made of a Ni-Ti-based shape memory alloy thin wire, characterized by removing the exterior material,

[0006] The invention of claim 2 is characterized in that the Ni-Ti
The system shape memory alloy strand is Ni49.5-51.5 at.
%, A Ni-Ti alloy consisting of the remaining Ti, and the Ni-T
Part of Ni and / or Ti in the i alloy is V, C
one or more of r, Fe, Co, and Al, and a total amount of Ni-substituted in a range of 0.1 to 3.0 at%.
Ti-based alloy, or the above-mentioned Ni-Ti alloy or Ni
-A part of Ni and / or Ti in the Ti-based alloy is any of Cu, Pd, and Nb and the amount is 5 to 10a.
The method for producing a stranded wire member comprising a Ni-Ti-based shape memory alloy thin wire according to claim 1, wherein the stranded wire member is made of a Ni-Ti-based alloy substituted in a range of t%.

According to a third aspect of the present invention, the Ni-Ti based shape memory alloy strand is a strand whose surface is previously cleaned. T
A method for producing a stranded wire member comprising an i-type shape memory alloy thin wire,

[0008] Further, in the invention according to claim 4, the exterior material includes:
4. The method according to claim 1, wherein the stranded wire member is made of a mild steel material or a Cu-Ni-based alloy material.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, each of the above inventions will be described in detail. First, the invention of claim 1 will be described.
According to the first aspect of the present invention, the Ni-
While holding a plurality of Ti-based shape memory alloy wires at a temperature higher than the transformation point of the wires, the wires are covered with a metal exterior material to form a composite wire, and then the composite wire is formed. The wire is repeatedly subjected to cold drawing and annealing to form a composite wire, then the composite wire is twisted, and then formed into a predetermined length and shape to form a composite wire. As a wire member,
Next, this is a method for manufacturing a stranded wire member in which a shape memory treatment is applied to this and then the exterior material is removed.

According to the present invention, first, an exterior material such as a mild steel pipe (J
Within the IS standard G34541), Ni-
A plurality of Ti-based shape memory alloy strands are inserted in parallel to form a composite strand, and the composite strand is repeatedly subjected to cold drawing and annealing to form a thin wire inside the exterior material. For example, a large number (a bundle of fine wires) of Ni-Ti-based shape memory alloy fine wires having a diameter of 500 µm or less are manufactured at the same time. That is,
According to the present invention, composite wires are produced by inserting straight wires subjected to linear memory processing in a state parallel to each other into a cladding tube as an exterior material, and processing (drawing) and annealing the composite wires. When the diameter is repeatedly reduced to form a composite wire, the Ni-Ti-based shape memory alloy wire inserted into the exterior material is
For example, even if a thin wire having a diameter equivalent to a diameter of 250 μm is obtained, a bundle of fine wires having no oxide on the surface can be obtained without disconnection or extreme variation in thickness. Here, the cold drawing includes warm working at a recrystallization temperature or lower, that is, working at 500 ° C. or lower. It has been found that by raising the temperature, the working during the annealing can be increased, and that the wires are not joined in the above temperature range. The thin wires inside the exterior material obtained in this way basically have a hexagonal cross section, and even after the exterior material is removed, each of the thin wires is not joined, and the thin wires separated from each other. Is obtained.

In the manufacturing method of the present invention, the linear memory processing is performed in advance on the Ni—Ti based shape memory alloy wires to be inserted into the exterior material because the wires are inserted in parallel with the exterior material. This is so that The conditions for the linear storage processing of the Ni—Ti alloy wire are 350 to 900 ° C.
The heat treatment is preferably performed at a temperature of 450 to 750 ° C. while running the wire linearly (heat treatment during running,
Annealing during running). In addition, the reason why the wire is inserted into the exterior material while maintaining the wire at a temperature higher than its transformation point (Af point) is that the Ni-Ti-based shape memory alloy wire that has been subjected to the linear memory processing is inserted. Until the completion, the straight line is maintained so that each line is inserted in parallel without intersecting. When dealing with these long strands, the transformation point (A
When the point (f) is higher than room temperature, if the wire is fed straight into a composite process while heating through a heating furnace or the like, the wires will not overlap, and the longitudinal direction of the composite drawn material after wire drawing will be eliminated. Can prevent shape fluctuation and disconnection.

As described above, a plurality of strands are inserted into or covered with the sheathing material to form a composite strand, which is then repeatedly subjected to cold reduction and annealing in a conventional manner. Then, the diameter is reduced to obtain a composite wire having a predetermined size, and then the composite wire is subjected to a twisting process. The reason why this composite wire is subjected to twisting is to make the bundle of fine wires inside the exterior material into a stranded wire at this stage. At this stage, the twisted member is subjected to the twisting process on the composite wire with the outer member covered, so that the stranded member can be directly obtained after the outer member is removed later.

After the composite wire is twisted, it is formed into a predetermined length and shape to obtain a twisted composite wire. For example, in the case of a brass stranded core material, the twisted composite drawn material (FIG. 6) is cut into a predetermined length and formed into a curved shape as shown in FIG. A torsion composite wire drawing member for a brassier core material. When a stranded wire spring material is used, the wire is cut to a predetermined length and formed into a spring shape to obtain a torsion composite wire drawing member for a spring. Furthermore, when a guide wire is formed by a stranded wire such as a conduit tube, since the guide wire is used in a straight line, it is merely cut into a predetermined length.

In the present invention, a shape memory process is performed after cutting and molding according to the purpose of use as described above. This heat treatment is performed at 350 to 900 ° C., preferably at 40 ° C.
Performed at a temperature of 0-600 ° C. Here, the shape memory processing is performed for the purpose of keeping the stranded wire inside the exterior material without breaking the stranded wire and storing the shape in use. The shape in use is, for example, a curved shape in the case of the above-mentioned brass stranded core material, and a spring-like shape in the case of the stranded wire spring material. Further, in the case of a guide wire formed by a stranded wire such as an electric conduit, the wire has a straight shape.

In the present invention, after the shape memory process is performed, the exterior material is removed to obtain a stranded wire member suitable for each purpose. In addition, by performing a shape memory process before removing the exterior material, a stranded wire member obtained by each thin wire has shape memory and superelastic properties.

The details of the material of the metal for the exterior material for inserting or coating the Ni-Ti based shape memory alloy wire will be described in claim 4 described later, but the shape of the exterior material is as shown in FIG. An outer casing made of a seamless pipe, an outer casing made of a formed welded pipe as shown in FIG. 4, an outer casing made of a lap wound tube as shown in FIG. 5, and an outer casing made of a metal tape can be used.

Next, the second aspect of the present invention will be described.
The Ni-Ti based shape memory alloy used in the present invention is Ni-
Any alloy based on a Ti alloy can be used. That is, Ni-Ti binary system, and V,
It can correspond to a multi-element alloy to which elements such as Cr, Fe, Co, Al, Cu, Pd, and Nb are added. The invention of claim 2 is a preferred embodiment of the Ni-Ti based shape memory alloy strand inserted into the exterior material. That is, the Ni—Ti-based shape memory alloy strand had Ni of 49.5 to 51.5 at% and the remaining T
i, a Ni—Ti alloy, and a part of Ni and / or Ti in the Ni—Ti alloy are V, Cr, F
e, one or more of Co, Al, and a Ni—Ti alloy substituted with a total amount of 0.1 to 3.0 at%, or the Ni—Ti alloy or Ni—Ti
Ni or / and part of Ti in the base alloy is Cu,
This is a Ni-Ti alloy substituted with either Pd or Nb in an amount of 5 to 10 at%.

Ni 49.5 to 51.5a used in the present invention
t%, in the remaining Ti-Ni alloy, Ni and Ti
The reason for the above composition range is that a shape memory effect or a superelastic effect cannot be obtained if the composition is less than the lower limit or exceeds the upper limit.

Further, the Ni—Ti alloy used in the present invention is the same as the Ni—Ti and / or T
a Ni-Ti alloy in which a part of i is one or more of V, Cr, Fe, Co, and Al, and the total addition thereof is substituted in a range of 0.1 to 3.0 at%; Such an alloy composition is used in order to improve the material strength, manufacturing workability, and the like without having the shape memory effect or the superelastic effect described above, and without impairing the characteristics. If the total amount of the respective additive elements is less than 0.1 at%, the effect is small, and if it exceeds 3.0 at%, the workability at the time of wire drawing decreases. Therefore, the total amount of the substitutional addition of each element is in the range of 0.1 to 3.0 at%.

Further, the Ni-Ti alloy used in the present invention is the above-mentioned Ni-Ti alloy or V, Cr, Fe, C
o, a part of Ni and / or Ti in a Ni-Ti alloy containing one or more of Al, Cu, Pd,
This is a Ni—Ti alloy substituted with any of Nb and in an amount of 5 to 10 at%. C if necessary
u, Pd, or Nb, and the amount is 5 to 10 a
When the substitutional addition is performed in the range of t%, if the content is less than 5 at%, the shape memory or superelastic properties are insufficiently improved.
If the content exceeds 0 at%, workability deteriorates and commercialization becomes difficult.

Next, the third aspect of the present invention will be described.
The invention of claim 3 is an embodiment of the invention of claim 1,
The Ni-Ti based shape memory alloy strand uses a strand whose surface has been cleaned in advance. Specifically, each wire is pickled, subjected to a linear memory treatment in the air or in an inert atmosphere, and inserted into a sheathing material (seamless pipe) as shown in FIG. After forming the strands,
As shown in the figure, one end of the composite element wire is knotted by a swager, and then drawn from this knot portion, so that the armoring material and the Ni-Ti alloy element wire or element wires come into close contact with each other, and The air inside the material is discharged to the outside. By doing so, the surface of the internal Ni—Ti-based alloy wire is not oxidized in the subsequent drawing and annealing steps. In the case of a short wire, as shown in FIG. 3, a Ni-Ti alloy wire similar to the above is inserted into the exterior material, and both ends are vacuum sealed to form a composite wire, which is then cold drawn. By repeating the wire and annealing to reduce the diameter, a clean fine wire whose surface is not oxidized can be obtained.

Next, the invention of claim 4 will be described.
The invention according to claim 4 is a preferred embodiment of the invention according to claim 1, wherein the exterior material is made of a mild steel material or a Cu-Ni alloy material. The exterior material used in the present invention is not limited to the above, but mild steel or Cu-
It is preferable to use a Ni-based alloy material. The mild steel material preferably has a carbon content of about 0.15 to 0.3% in view of having appropriate mechanical properties and workability. In a medium carbon steel having a carbon content of 0.3 to 0.5%, the deformation resistance is too large and processing becomes difficult. Further, Cu-Ni-based alloy material is
It is preferable because it has appropriate mechanical properties and workability.
For example, Cu and Cu-Zn alloys are too soft or unsuitable due to crystal grain coarsening during heat treatment.

In the case where a short strand is used in a small amount of production, it is convenient to use a short mild steel pipe. In addition, when using a long strand, as shown in FIG.
The wire may be supplied while forming and welding the tape material as the exterior material, and as shown in FIG. 5, a method of wrapping the wire while forming the tape material may be used.
Conventional techniques can be employed.

In the manufacturing method according to the present invention, a composite element wire is formed by combining an exterior material and a plurality of Ni-Ti-based shape memory alloy elements subjected to linear memory processing, and this is processed (drawn and annealed).
Therefore, many small-diameter wires can be obtained simultaneously and easily without oxidizing the Ni-Ti-based shape memory alloy wires. In addition, the manufacturing method according to the present invention can reduce the wire drawing rate during annealing by about 20 to 30% as compared with the conventional single wire drawing, and can manufacture a plurality of wires at the same time. Can be manufactured. In addition, mild steel or Cu-
Since the Ni-based alloy material is used, the degree of seizure to the wire drawing die is smaller than that of the single wire drawing of the Ni-Ti shape memory alloy, so that there is an effect that there is no disconnection in the wire drawing process.

Further, in the manufacturing method according to the present invention, since the twisting is performed at the stage of the composite wire having the outer material covered, the bundle of fine wires inside the outer material may be formed into a stranded wire. it can. Therefore, the stranded wire member can be directly obtained after the exterior material is removed later. Further, in the manufacturing method according to the present invention, the twisted composite wire is processed into a predetermined length and shape, and then subjected to shape memory heat treatment. There is an effect that a wire member can be obtained. As described above, the manufacturing method according to the present invention can easily and inexpensively manufacture a stranded member made of a Ni—Ti based shape memory alloy thin wire.

[0026]

Next, examples of the present invention (examples of the present invention) will be specifically described. [Example 1] Ni having a diameter of 1 mm was 51.0 at% and the remaining Ti was
After pickling the Ni—Ti alloy strand consisting of, a linear memory treatment was performed in argon gas at 650 ° C. to impart superelastic properties. The transformation point (Af point) of this wire is −10 ° C. Next, outer diameter 9mm, inner diameter 5mm, length 1000mm
As shown in FIG. 1, nineteen wires subjected to the straight-line storage process were applied to a mild steel (SS41) cladding tube (exterior material) at room temperature.
The composite wires were prepared by inserting the wires in parallel.

Next, as shown in FIG. 2, one end of the composite wire was drawn with a swager, and drawn without annealing until the cladding tube and the Ni—Ti alloy wire were completely adhered.
This is because the air inside the composite wire is completely expelled, and the Ni-T during processing (drawing and annealing) is removed.
This is for preventing surface oxidation of the i-based alloy strand. next,
This composite strand was repeatedly subjected to annealing and cold drawing at 700 ° C. for 20 minutes, and the outer diameter of the composite drawn wire was 2.25 mm.
Wire was drawn until. Cut a part of this composite wire,
When the cladding tube was removed and inspected, the internal Ni-
The Ti-based alloy fine wires could be easily separated one by one. The cross section of the thin line is almost hexagonal, and the opposite side is 2
50 μm, less surface oxidation, cross-sectional shape (area)
Was almost constant, and it was confirmed that a bundle of fine wires (19) without disconnection was obtained.

Next, the composite wire thus manufactured was subjected to a twisting process at a pitch of 4.5 mm as shown in FIG. Subsequently, the twisted composite wire rod was cut into a predetermined length and formed into a brassier core material as shown in FIG. next,
The formed member was subjected to shape memory heat treatment at 500 ° C. × 1 hr, and then the exterior material was removed to obtain a stranded wire member for a brassier core consisting of 19 thin wires. A characteristic test was performed on the stranded wire member for a brassier core material, and as a result, it was confirmed that the braided core member had superelastic properties and was very flexible.

Example 2 A cladding tube (outer diameter 9
mm, inner diameter 5 mm, length 2500 mm) as Cu-N
i-based alloy, JIS7100 (Cu-20wt% Ni-
0.8 wt% Fe-0.5 wt% Mn alloy), in the same manner as in Example 1, Ni of 5 mm at 1 mm and residual Ti
The composite wire was manufactured by inserting 19 Ni-Ti alloy wires consisting of Next, in the same manner as in Example 1, the composite element wire was processed and drawn until the outer diameter of the composite drawn material became 5.0 mm. A part of this composite wire was cut, and the cladding tube was removed with a blade to investigate. As a result, it was possible to easily separate the internal Ni—Ti-based alloy wires one by one. The cross section of the thin line is almost hexagonal, and the opposite side is 500 μm.
It was confirmed that a bundle of fine wires (19 wires) with little surface oxidation, almost constant cross-sectional shape (area), and no disconnection was obtained.

Next, the composite wire thus produced was subjected to a twisting process at a pitch of 4.5 mm as shown in FIG. Subsequently, the twisted composite wire was cut into a predetermined length of 5000 mm to obtain a guide wire member formed by stranded wires of a conduit tube. Next, this member was subjected to a heat treatment of a linear shape memory at 600 ° C. for 30 minutes, and then the sheath material was removed to obtain a stranded wire member for a guide wire of a conduit made of 19 thin wires. A characteristic test was performed on the stranded wire member for a guide wire, and as a result, it was confirmed that the stranded wire member had superelastic properties.

[0031]

As described above, according to the present invention, Ni-T
By being able to simultaneously produce a plurality of thin wires of the i-based shape memory alloy, to be able to twist and twist a bundle of these thin wires at the same time to form a stranded wire, and to be able to simultaneously shape-process this stranded wire member, It is possible to supply inexpensively a stranded wire member made of a Ni-Ti alloy thin wire having shape memory properties or superelastic properties, and has a remarkable industrial effect such that a wide range of application development can be developed. .

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of a composite element wire made of a seamless pipe sheathing material.

FIG. 2 is an external view of a composite element wire whose one end is squeezed by swaging.

FIG. 3 is an external view of a composite element wire having both ends vacuum sealed.

FIG. 4 is a cross-sectional enlarged view of a composite element wire formed by a forming material for a welded pipe;

FIG. 5 is an enlarged cross-sectional view of a composite strand using a forming wrapped tube sheathing material.

FIG. 6 is an external view of a composite wire obtained by drawing a composite wire into a composite wire and further twisting the composite wire.

FIG. 7 is an embodiment of the present invention, which is N for a brassier core material.
1 is an external view of a stranded wire member (twisted composite wire drawn member) made of an i-Ti-based shape memory alloy thin wire.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ni-Ti alloy wire 2 Metal exterior material 21 Exterior material by seamless pipe 22 Exterior material by forming welding tube 23 Exterior material by forming lap winding tube 3 Swager processing part 4, 4 ^' sealing part 5 Welding part 6 Overlapping part 7 Torsion composite wire drawing material 8 Molded torsion composite wire drawing member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B21F 21/00 B21F 21/00 C22C 14/00 C22C 14/00 Z 19/03 19/03 A

Claims (4)

[Claims] 1. Ni-Ti which has been subjected to a straight line storage process in advance
While holding a plurality of the system shape memory alloy wires at a temperature higher than the transformation point of the wires, the wires are covered with a metal exterior material to form a composite wire, and then the composite wire is formed. For the wire, after repeated cold drawing and annealing to make a composite drawn material,
This composite wire is subjected to a twisting process, and then formed into a predetermined length and shape to form a twisted composite wire, and then subjected to shape memory processing, and then the exterior material is removed. A method for manufacturing a stranded wire member made of a Ni-Ti based shape memory alloy thin wire, characterized in that: 2. The Ni—Ti based shape memory alloy strand is:
Ni 49.5 to 51.5 at%, Ni-
In the Ti alloy and a part of Ni and / or Ti in the Ni—Ti alloy, V, Cr, Fe, Co, Al
Species or two or more species, and the total amount is 0.1 to 3.0a
Ni-Ti alloy substituted in the range of t% or Ni in the above-mentioned Ni-Ti alloy or Ni-Ti alloy
And / or Ni in which part of Ti is substituted with any of Cu, Pd, and Nb and the amount thereof is in the range of 5 to 10 at%.
The method for producing a stranded wire member made of a Ni-Ti-based shape memory alloy thin wire according to claim 1, wherein the stranded wire member is made of a -Ti-based alloy. 3. The Ni—Ti based shape memory alloy strand is:
3. The method for producing a stranded wire member made of a Ni-Ti based shape memory alloy thin wire according to claim 1, wherein the wire is a wire whose surface is previously cleaned. 4. The exterior material is made of mild steel or Cu—N.
The method for producing a stranded wire member comprising a Ni-Ti-based shape memory alloy thin wire according to any one of claims 1, 2, and 3, wherein the method is made of an i-based alloy material.