JPS62290529A - Niti group alloy material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention improves wire drawability and coiling property by coating a core material made of a NiTl alloy with a coating material. This invention relates to a NiTi-based alloy material that is significantly improved.

[Conventional technology]

In recent years, various research and development efforts have been conducted to put N I Ti alloys made of Ni and Ti into practical use because they have shape memory performance, superelasticity, vibration damping performance, and the like.

However, in general, the workability of such NiTi alloys is very poor. For example, during wire drawing, the life of the die is shortened due to the phenomenon of seizure with the wire drawing die, and wire breakage occurs frequently, resulting in poor wire drawability. Therefore, there are problems in that the processing rate per die has to be set low, which is a part of increasing production costs.

In particular, in the conventional production of NiTi alloys, most of the N
Since it is obtained by repeatedly performing heat treatment and diameter reduction processing on an ingot obtained by melting i and Ti,
How to increase the processing rate during heat treatment is a very important issue.

In addition, the alloy is often processed into springs, etc., but even in this case, the alloy has poor coiling processability, and new measures are required to suppress tool wear to a low rolling force. Ta.

To solve some of these problems, for example, Japanese Patent Application Laid-Open No. 60-9865 proposes forming an oxide film on the surface and using this oxide film as a lubricating film. There is.

[Problem that the invention seeks to solve]

However, since this oxide film is generally a hard substance in the form of fine particles, during various processing, it tightly and firmly adheres to the relatively soft surface layer of the base material, and in some cases, it also bites into the inside of the base material. In addition to this problem, such an oxide film also has the disadvantage of actually accelerating die wear. Particularly, such a phenomenon changes depending on the degree of the processing, and seems to increase as the processing is performed to a high degree or the diameter is reduced many times (for example, wire drawing).

In addition, since the oxide film has a black color, it reduces the appearance.
Decrease product value. Therefore, depending on the application, it is necessary to remove this oxide film, but as mentioned above, it is extremely difficult to uniformly and completely remove even the oxide film that has penetrated firmly into the base material.

Conventionally, nitric acid solution or electrolytic pickling has been used to remove the oxide film, but in this case, if too much liquid is removed, the base material itself will be dissolved and the wire diameter will be reduced. There is also concern that new problems such as increased variation in surface properties or deterioration of surface properties may occur, and that hydrogen may be occluded during processing, resulting in hydrogen embrittlement.

Another relatively easy method, for example, is to coat the surface of the base material with a metal or organic substance.
Since the N i Ti alloy contains a large amount of Ti element therein, a mere coating alone has poor adhesion, so such a product has not yet been realized.

[Purpose of the invention]

The present invention improves the adhesion of the core material, greatly improves its processability, and improves the commercial value of the final product.
The purpose is to provide alloy materials.

[Disclosure of the invention]

An embodiment of the present invention will be described below based on the drawings.

The N i T l alloy material 1 of the present invention includes Ni 48 to
53a t% and the remainder is Ti, or a part of the Ni or Ti is Cu, V% M OlCr s
A7! , Fe, and Zr, or by baking a resin paint with a heat-resistant temperature of 300″C or more on the surface of the core material 2, which is made of a NiTi-based alloy substituted with one or more elements selected from the group consisting of , Fe, and Zr, or a soft metal material. It is characterized in that it is coated in close contact with any of the following coating materials 3.

The core material 2 made of NiTi alloy has a thickness of 48 to 53 at.
% of Ni and the remainder is Ti, and the whole is a so-called pure NiTi phase. Elements and materials are also used.

Substitution with such elements is effective for improving the transformation point of the core material 2 (NiTi-based alloy) itself, as well as other properties such as mechanical properties, corrosion resistance, and workability. It is preferable to implement the element in a range of 5 at% or less of the entire core material 2.

Within this range, the various functions such as the shape memory performance and superelasticity that the NiTi phase originally has are not affected, and as a NiTi alloy with such a composition, for example, conventionally produced melting In addition to enclosing a large number of wires made of a combination of Ti wires and Ni materials with an exterior material, the inside of the N fibers obtained by the powder alloy method and powder alloy method is of Ti
N i Ti -based alloys can be used that are manufactured by various methods, such as a method in which N and Ni are interdiffused to form a uniform N1Tt phase alloy.

In particular, according to the above-mentioned method utilizing interdiffusion, the NiTi alloy after the removal of the sheathing material has excellent compositional uniformity, and moreover, as shown in FIG. Since a large number of fine grooves 4 are formed extending toward the end, the present invention is extremely effective.

In the present invention, the surface of the core material 2 has a heat resistance temperature of 300
Since the coating is performed by baking a resin paint at a temperature of 0.degree. C. or higher or by coating with the coating material 3 made of a soft metal material, it has sufficient adhesion compared to ordinary coating methods.

The coating material 3 protects the core material 2 and provides sufficient workability and lubricity during wire drawing, coiling, and other various processing, and is a material for this purpose. For example, fluororesin, enamel,
A resin paint such as borosiloxane resin is baked onto the surface of the core material 2, or a metal material such as p' e SCu % N 1-monel alloy is applied by thermal spraying, vapor deposition, plating,
Alternatively, it can be coated by a cladding method. In particular, when using the latter metal material, prior to normal heavy processing after the coating, light processing is performed in advance at a processing rate of about 20% or less to ensure sufficient adhesion to the core material 2. Furthermore, since the metal material is soft, highly ductile, and has low work hardenability, its workability is sufficiently maintained.

Moreover, such a metal material can be removed, for example, chemically, if necessary after being formed into a final product.

On the other hand, even in the former method of baking resin paint, the core material 2 is often used as a functional alloy such as a shape memory alloy or a superelastic alloy, and in order to impart the above-mentioned function, the core material 2 is Since the heat treatment is performed at a temperature of 300° C. or higher, the heat-resistant temperature must be 300° C. or higher.

In addition, the resin paint contains, in order to improve its adhesion,
It can be used together with an undercoating material, and furthermore, various colors can be given to the paint by appropriately mixing various pigments such as red, blue, and green, so that the characteristics of the core material 2, for example, Color-coding for each metamorphosis point makes it extremely easy to sort or identify them.

In order to coat such a resin paint, for example, NiT is added to the base coat material or coating material that has been prepared in advance to a predetermined composition.
1 alloy material is dipped, then dried and baked at about 200 to 300'C.

By the above method, Ni with very good adhesion can be obtained.
Although Ti-based alloy materials can be obtained, the inventor of the present application
Furthermore, we focused on the surface condition of the core material 2 and attempted to further improve it through various experiments. As a result, on the surface of the core material 2,
A plurality of fine A4-- extending from one end to the other end.
It was confirmed that the formation of the coating material 3 increases the adhesion retention force with the coating material 3, and as a result, it is extremely effective in improving the lubricity. As seen in FIG. 2, the fine grooves 4 are formed substantially only in the longitudinal direction, and this directionality is also the same as the running direction of the material during processing. Even in severe processing involving bending, troubles such as cracking and peeling of the coating material 3 can be prevented.

As the core material 2 having such fine grooves 4, one obtained by the above-mentioned diffusion treatment method can be suitably employed. The enlarged view shown in FIG. 3 illustrates the cross-sectional state of a core material 2 having fine grooves 4 coated with the resin coating material 3. According to the figure, the surface of the core material 2, which has complex irregularities, is uniformly covered with the coating material 3, and the coating material 3 completely penetrates into the depths of the fine grooves 4. It can be seen that it is closely attached to Note that the core material 2
By the primary forming, for example, wires with circular cross sections, rods, various other shapes (cross sections: triangular, square), plate materials, pipe materials, etc. can be freely formed, and the coating material 3 is also sufficient. Since it has thermal properties and lubricating properties, it is possible to perform a superheating treatment to obtain a predetermined function (for example, shape memory performance) while it is in a coated state.

〔Effect of the invention〕

As detailed above, the NiTi alloy material of the present invention has heat resistance on its entire surface, /I2I? It is coated with metal materials and resin paints that have excellent fk properties, and is specially treated to ensure sufficient adhesion to the core material, making it possible to set large processing rates even in various types of heavy processing. It's possible.

Therefore, cost reduction of the NiTi alloy is promoted, and the surface of the alloy can also be colored in various ways, which can be used to improve the commercial value and differentiate the characteristics of the product.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the present invention, FIG. 2 is a perspective view showing fine grooves, and FIG. 3 is an enlarged view of a core material coated with a resin film. 2.-Core material, 3.-Test material, 4.--Minute groove. Patent applicant: Nippon Seisen Co., Ltd. Agent Patent attorney: Tadashi Naemura N5g

Claims (2)

[Claims] (1) 48 to 53 at% Ni and the balance is Ti, or a part of the Ni or Ti is made of Cu, V, Mo, Cr.
, made by baking a resin paint with a heat resistance temperature of 300°C or higher on the surface of a core material made of a NiTi alloy substituted with one or more elements selected from the group consisting of Al, Fe, and Zr, or a soft metal material. A NiTi-based alloy material characterized by being closely coated with any of the following coating materials. (2) The NiTi-based alloy material according to claim 1, wherein the core material has a plurality of fine grooves formed on its surface extending from one end toward the other end.