JPS59116340A - Production of shape memory alloy material - Google Patents

Abstract

PURPOSE:To obtain an NiTi memory alloy material with a simple production stage and high productivity by bringing an Ni material and a Ti material into tight contact with each other by a film forming method of press welding, plating or vapor deposition, heating the materials and forming an NiTi phase by reactive diffusion. CONSTITUTION:An Ni material and a Ti material are brought into tight contact with each other and thereafter the materials are heated and a TiNi phase is formed by reactive diffusion. The pure Ti rod 1 and pure Ni rod 2 are clad whereby the construction laminated with the Ti material and the Ni material can be obtd. in this case. The laminated rod is then heated to diffuse Ti to the Ni side and Ni to the Ti side. An intermetallic TiNi compd. layer 4 is formed in the central part by said diffusion. The layer 4 contains the three phases; Ti, Ni, TiNi and TiNi3. However if the Ti and Ni are beforehand so selected as to be incorporated at 1:1 by atom ratio and are heated for a long time, the intended shape memory alloy consisting of the rod of the single phase composed only of the TiNi phase 3 is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing shape memory alloy materials, particularly NIT
We will discuss the manufacturing method of i-based shape memory alloy material.

Description of the Prior Art In general, Nt-"i-thread shape!![! Memory alloys are manufactured by vacuum melting, homogenization annealing, hot working, cold working, intermediate softening (the intermediate softening process such as cold working is repeated). However, in the conventional manufacturing method as described above, (I2+ and N1 are alloyed by melting Disadvantages include the difficulty in controlling the target composition and the unavoidable contamination of gaseous impurities such as oxygen and carbon from graphite melting. Disadvantages include the need to reheat the ingot and the surface being easily oxidized by heating.
and (c) because cold rolling is performed, it is not possible to increase the degree of work in one round, and therefore it is necessary to repeat intermediate softening many times (increasing the degree of work in each time, or If the number of times is reduced, fractures occur during processing) and oxidation occurs during intermediate softening. In this case, an extremely large number of steps are required, and the retention rate is low due to the effects of the oxidized layer, resulting in extremely low productivity and high stress.

By the way, Nl'li is a metal open compound with a silk ratio of approximately 1:1. Kawaden SNb is a method for producing chalcolithic compounds.
A reaction-diffusion method is known, which is applied to the production of Snl materials. If this reaction-diffusion method can be applied to the production of Ni1i shape memory alloy, NiT
It is possible to produce a ll-based memory alloy material. Therefore, it has been desired to develop a method for producing shape memory alloy materials using a reaction diffusion method.

Purpose of the Invention Therefore, the main purpose of the present invention is to provide a method for manufacturing Nll'i-based shape memory alloy materials that has a simple manufacturing process and excellent productivity by eliminating the drawbacks of the conventional manufacturing method described above. It is about providing.

In summary, the present invention is a shape memory material characterized in that a Nl material and a 7i material are brought into close contact with each other by pressure welding or a film forming method such as plating or vapor deposition, and then heated to obtain a TiNi material by reaction diffusion. This is a method for manufacturing an alloy material. In Suimei M-sho, "Toj1 material" and "Ichikawa material" refer to materials in the shape of strips or lines, respectively, made of N1 and T1. Prior to the reaction and diffusion between the Nl material and the Ti material, [L;
I > Either plating (4-type plating) or dry plating is acceptable, ), (C) ■2N+>Ni to pipe (
Ti) Insertion and pressure welding of wire and (d) Tt (Ni
) can be done by various methods, such as N1 (TI) evaporation onto the wire.

The manufacturing method of the present invention is to bring the above-mentioned Ni material and Ti material into close contact with each other, and then heat and react and diffuse 1 to 7 pieces of TlN.
It is something that 1 to 3 are cross-sectional views of a casing for detailed explanation of the invention.

As shown in Fig. 1, by cladding n-r+ strip 1 and llll strip 2, 11 structures made of Ti and Ni materials can be made into 17. :l) I
When heating the I strip, T1 moves to the Ni side, and the Ni
The soybean spreads to the Ti side. At this time, as shown in FIG. 2, a T1Ni intermetallic compound layer 4 is formed in the central portion.

This Ti Ni gold pentate compound Fi14 is ri y N
i, TI Ni J3J:bilN1. (7) Contains three phases. However, if 11 and N1 are selected in advance in an atomic ratio of 1:1 and heated for a long time, a single-phase strip consisting only of the TiNt phase 3 can be produced () as shown in Fig. 3. .

4 to 3 (FIG. 3 is a schematic perspective view for explaining another example of the ¥J manufacturing method of the present invention. As shown in FIG. 4, -ri fil 1 is inserted into the N1 vibrator 10. After wire drawing, TI and N1 are brought into pressure contact by heating the structure, which is joined by t, , L/. Similarly °1−i
It is possible to produce a single-phase conductor 3 consisting only of Ni. ,
Note that, like FIG. 2 of the first example, FIG. 5 is a diagram showing a state in the middle of the diffusion process.

According to a preferred embodiment, the Ni material and the Ti material are brought into close contact with each other by pressure welding or plating so that the Ni content is 50 to 60% by weight. The r amount ratio of Nl is in this range 1! J
This is because by selecting l, it is possible to obtain a more excellent shape memory effect.

Further, Nil'i itself has poor workability.

In other words, it is extremely difficult to carry out various types of processing such as casting, hot working (+5 J: and cold working 4ζ).

On the other hand, Ni or lt is a material 1 that is relatively easy to process. Therefore, in a preferred embodiment, the N+T+ shape memory alloy material in the desired shape is obtained by adding Ni material and ' or l- to the material in advance, and then adhering and heating the material to obtain the desired composition. In order to obtain the desired shape, the Ni material and the Ti material may be brought into close contact with each other, and then subjected to cold or warm processing to form a desired shape, and then heated.

In a preferred embodiment, at least 1 cold or warm
Processing is performed with an area reduction rate of 0% or more. This is because diffusion is more likely to occur and the strength of the product deteriorates.

The rll materials "J" and "rTiUJ" used in this invention include not only the material r1 consisting of pure N1 or 1: but also a portion of which is CIJ, Δf1. V, Zr, MO, Cr.

[It may contain one or more elements selected from the group consisting of e, Co, and @earth elements. By using a material containing such elements, it becomes possible to control the state temperature B.

Other objects and features of the invention will become more apparent from the following detailed description with reference to the drawings.

DESCRIPTION OF THE EMBODIMENTS Embodiment As shown in the cross-sectional view C in Fig.
()tnmc') in l i Article 1 and) li N
The i-strip 2 was rolled and the whole was clad to a V height of 0.2 mm by warm rolling or cold rolling. Next, L1 on the vacuum instep
Heated at a temperature of 2 (100 (J℃) for 10 (J hours). The rl Nl i glue generated at this time was 0.-1 m +
In addition to this, Ti 2 Ni and ri
It was thicker than Ni. The thus formed strips were fixed in a straight line and held at 500°C for 115 minutes to memorize the linear shape, deformed into a curved shape in ice water at 0°C, and then placed in warm water at 70°C. When immersed, it completely returned to its original straight shape.

Example 2 As shown in Fig. 4, inner diameter 1 mm 1 JRF10, 2
11111 (7) Pure Ni pipe 10, outer diameter 0.8++
Insert +m no l ri l111, 0.51!111
C wire was drawn to 1φ, and N1 and 11 were completely brought into contact. Next, it was heated in vacuum at a temperature of 900° C. for 100 hours. At this time, the wire rod is a single 1-tN+N as shown in FIG.
It became i material.

This wire '4A was wound and fixed in a coil around a copper rod having an outer diameter of 20111111 and held at a temperature of 550° C. for 10 minutes to memorize the coil shape. Next, the coil was stretched in ice water at 0°C, and then immersed in warm water at 60°C, completely recovering its original coil shape.

Taiyangou 1 A Ni base metal sheet with a thickness of 30 μm containing 0.5% l”e was coated with “I” (= J) to a thickness of 50 μm, and this was lightly rolled. Next, , 70 at a temperature of 980℃
Heated in vacuo for an hour. Apply tension to the created sheet.
It was heated at a temperature of 450'C for about 15 minutes while being flattened. Next, at room temperature, this flat lζ sheet 1-
When I rolled it up into a comb and put it into a device, it recovered to its original plane + 1 ji shape (Matsu-11 characteristic behavior). ?l
It was found that heat treatment at high humidity and for a long time is necessary to form a thick T1Ni phase. For example 100
By heating for 100 U1 at a temperature of 0°C, approximately 0.
A 1 mm T1Ni layer was produced. Therefore, the thinner the plate thickness or the smaller the diameter of the wire, the more Ti Ni
You can see that you get layers. Therefore, it is possible to obtain very thin NlTi alloy wires (A) very easily, which has been particularly difficult with conventional manufacturing methods.

Effects of the Invention As described above, according to the present invention, N1 material and Ti material are bonded together by a film forming method such as pressure welding, plating, or vapor deposition.
Since it is possible to obtain a TiNi material by heating in close contact and reaction diffusion, the processing process can be simplified very effectively.

That is, it is possible to omit a large number of steps such as hot heating 1 and cold working that were necessary in conventional manufacturing methods, as well as reheating steps and intermediate softening steps that were necessary in conjunction with these steps. Therefore, the processing process can be greatly simplified. Further, by applying processing in advance when joining 1i1A and N1t4, it is possible to extremely easily produce a shape and size close to the desired shape and dimensions. Furthermore, the thinner the original thickness of the UNi material is, the shorter the diffusion distance, which makes it possible to shorten the heating time, and therefore to manufacture thin plates, thin wires, etc. in a shorter time.

Further, since the number of steps can be reduced, the yield can be improved, and therefore, it is also possible to extremely effectively reduce the cost of the Nil'i-shaped tempering alloy material.

Manufacture of this invention)
It can be applied to the production of various shape memory alloys such as superelastic springs and anti-vibration materials, and its production chamber size is relatively large.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views for explaining an example of the manufacturing method of the present invention. Figure 3 shows the state in the middle of the diffusion process, Figure 3 shows the state in which mutual diffusion has completed.
A schematic perspective view showing another example of the manufacturing method of the present invention (with
Figure 11 (shows the connection state between the N+ pipe and the T(wire) -4
Figure 5 shows the state in the middle of diffusion (Fig. Article 2
HaN wo article, 3 +, + -ri N! i'U,
10 is the l-motion vibrator, 11 is the T1 warehouse LC134, and 12 is the FINi phase. Patent applicant: Sumitomo Electric Industries, Ltd. 1! (,+,,・

Claims (5)

[Claims] (1) Pressure welding or plating of Ni material and Li material is also possible L'
<vb) method for shape memory alloy materials, which is described as 1!5 characteristics in which the rTtNi phase is obtained by reaction diffusion by closely plating and heating by a film forming method such as soldering. (2) The above-mentioned Ni material and F; material have Ni of 50.
0ffT h'-96 with a strip, wire or pipe made of N1 or Ti, and Ti or N+1)
A method for producing a shape memory alloy material according to claim 1, wherein the shape memory alloy material is pressure-welded by joining with a strip, a gauze, or a pipe. (3) The Ni material and the 11 material have 1°i of 50-60.
Claim 1 JT! A method for producing a shape memory alloy material according to i. (4) Special iF'l! where the N1 material and Ti material are in close contact with each other and are heated after being processed to reduce the area by at least 10% in cold or wet conditions. A method for producing a shape memory alloy material according to claim 3 or 4. (5) At least one of the N1 material and TlI4 contains one or more elements selected from the group including Cu, Fe, Co, Am, V, Zr, and MO0 rare earth elements, and the heating At most 20% by weight of N1 or Yl
The method for producing a shape memory alloy material according to any one of claims 1 to 4, wherein is replaced with the goldite element.