JP2634789B2 - Method for producing titanium-clad-aluminum wire material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a titanium-clad aluminum wire material, and more particularly to a processability for producing a titanium-clad aluminum wire useful as a material for eyeglass frames, watch bands, accessories and the like. The present invention relates to a method for manufacturing an excellent material.

[0002]

2. Description of the Related Art As is well known, titanium or a titanium alloy is widely used as a material for eyeglass frames, watch bands, accessories, etc. because of its relatively light weight, strong corrosion resistance, and excellent non-allergenicity. Have been. However, pure titanium has a problem in strength and titanium alloy has a problem in workability. For this reason, the market seeks a material that is lighter, stronger and more workable than pure titanium. In response to this requirement, for example, a titanium-clad-aluminum wire material as disclosed in Japanese Utility Model Publication No. 64-6621 has been proposed, but a different metal or alloy is simply interposed between the core material and the coating layer. Could not solve the problems described below.

[0003]

As a result of many experiments conducted by the inventor, the following has become clear. That is,
Titanium-cladding-aluminum wire material, in order to undergo repeated processing of strength including heating at around 500 ° C in the process of processing into wire material, aluminum or aluminum alloy as the core material is only one layer of titanium or titanium alloy. When coated, the aluminum or aluminum alloy components (Al, Mg, Cu, Si, etc.) that make up the core material are activated,
It rapidly diffuses into the titanium or titanium alloy of the coating layer and combines with the titanium to form a brittle intermetallic compound, or unevenly formed defects such as cracks generated in the titanium or titanium alloy during processing. Diffuses and penetrates to produce the compound. For this reason, the structure becomes uneven and workability is poor, and it is difficult to obtain a wire. Furthermore, even if a thin clad wire can be manufactured, spot welding, brazing, etc. are indispensable in the manufacturing process of eyeglass frames, watch bands, accessories, etc. (900 ° C). An object of the present invention is to solve these problems and to provide a method for producing a titanium-clad-aluminum wire material which is light and has good workability.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for producing a titanium-clad-aluminum wire material, wherein a core material made of aluminum or an aluminum alloy is covered with a plurality of coating layers made of titanium or a titanium alloy. In addition, a diffusion prevention layer for aluminum or an aluminum alloy is provided on at least one of adjacent surfaces of the coating layer.

[0005] In the practice of the method according to the invention, the coating layer is formed from a first coating layer adjacent to the outside of the core and a second coating layer adjacent to the outside of the core layer, and is diffused. The prevention layer may be provided on at least one of the outer surface of the first coating layer and the inner surface of the second coating layer. In this case, it is preferable that the thickness of the first coating layer is formed smaller than the thickness of the second coating layer.
The diffusion preventing layer can be formed by oxidizing the surface of the coating layer.

[0006]

As described above, the material of the present invention is composed of a core material made of aluminum or an aluminum alloy and a plurality of coating layers made of titanium or a titanium alloy covering the core material. The diffusion or permeation of the aluminum or aluminum alloy component of the core material into the coating layer during the rolling process to the core is prevented by the diffusion preventing layer.
Therefore, the formation of the intermetallic compound is limited to the inside of the coating layer, and the structure in the coating layer is uniform. The composition and the structure of the coating layer located outside the coating layer are not affected by the diffusion. Therefore, the workability of the whole material is good, the material can be rolled to a small diameter, and no abnormal deformation or the like occurs during spot welding or brazing of a wire. The diffusion preventing layer can be easily formed by oxidizing the surface of the coating layer.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method of the present invention will be described with reference to FIGS. To make the core material 1, a commercially available aluminum alloy round bar (outer diameter 11 mm, Mg 0.63, Cu 4.6, Si
0.46, Mn 0.7 wt%) was cut into a length of 970 mm. In order to form the inner coating layer 2, a commercially available thin titanium pipe (outside diameter 13mm, inside diameter 12mm, wall thickness 0.5mm, Ti 99.7wt% or more) is used.
After cutting to 970 mm, it was heated at 600 ° C. for 30 minutes in an argon gas atmosphere. Further, in order to form the outer coating layer 3, a commercially available thick titanium pipe (20 mm in outer diameter, 13.5 mm in inner diameter, about 3.3
(mm, Ti 99.5 wt% or more) was cut into a length of 1000 mm, and heated at 600 ° C. for 30 minutes in an argon gas atmosphere. Next, in order to form a titanium oxide film acting as a diffusion preventing layer described later on the surface of the thick pipe, particularly on the inner peripheral surface, the pipe was heated at 300 ° C. for 10 minutes in the air. The thickness of the formed oxide film 3a was about 12 μm. Next, threads 3b and 3c each having a length of about 15 mm were provided on the inner peripheral surfaces at both ends of the thick pipe.

[0008] The core material 1, the inner coating layer 2 and the outer coating layer 3 prepared as described above were each washed with an appropriate detergent to remove adhering oil and dirt.
Next, as shown in FIG. 1, the core material 1 is inserted into the coating layer 2, which is inserted into the coating layer 3 to unite the three members, and then, as shown in FIG. 4 and 5 are screwed into threads 3b and 3c provided at both ends of the pipe constituting the coating layer 3 so that the core material 1 and the coating layer 2 are coated.
Fixed inside.

As described above, the diameter of the titanium-clad-aluminum wire material formed by combining the core material 1, the coating layer 2 and the coating layer 3 is reduced by cold swaging and swaging by a swaging machine. It gradually narrowed down while adding tanning. That is, the steel was first rolled to a diameter of 16 mm, and then annealed at 480 ° C. for 30 minutes in an argon gas atmosphere. Next, after changing the die and cold rolling to a diameter of 5 mm, annealing was performed again at 480 ° C. for 30 minutes in an argon gas atmosphere. Processing with a diameter of 5 mm or less was performed with a roller die, and a clad wire rod with a diameter of 3 mm was obtained as a product.

As a result of investigation on this wire, the density was 3.91.
g / cm ³ , tensile strength 581MPa, elongation 20.5 as mechanical properties
%, Drawing 60.5%, light weight, high strength, and extremely excellent workability. Good workability has a large effect of using aluminum as the core material. In the tensile test, so-called slip-through phenomenon due to peeling and slippage at the interface between the core material and the coating layer was not observed, and the layers were in good contact with each other.

In the microstructure of a cross section perpendicular to the longitudinal direction of the wire, three layers of a core 1, a coating layer 2, and a coating layer 3 are recognized from the center of the wire, and an interface between the core 1 and the coating layer 2 is observed. From inside to the inside of the coating layer 2, aluminum and the like in the core material diffuse and permeate to form a brittle intermetallic compound, but this diffusion is performed by a diffusion prevention layer previously formed on the inner peripheral surface of the coating layer 3. It was found to be prevented. This is due to the Vickers hardness (Hv) (1) depending on the distance from the center of the wire shown in FIG.
It is clear from the measurement results of the change of 00gf). That is, in the coating layer 3, since there is no diffusion of aluminum due to the effect of the diffusion preventing layer, the coating layer 3 becomes only titanium, and no decrease in hardness is observed. According to the microanalyzer, the coating layer 2
Indicates the presence of an intermetallic compound containing aluminum and titanium as main components, and the hardness has an intermediate value between aluminum and titanium. It should be noted here that the presence of the diffusion preventing layer makes the penetration of aluminum and the like in the inner coating layer 2 uniform, so that the microstructure of the cross section of the wire becomes uniform, and spot welding is performed. It is considered that abnormal deformation or the like hardly occurs during brazing or the like.

In the above embodiment, an aluminum alloy was used for the core material. However, pure aluminum may be used in some cases, and a titanium alloy may be used for the coating layer in addition to pure titanium. The characteristics of the wire can be greatly changed as needed. Further, the number of coating layers may be three or more. When the number of coating layers is two as in the above embodiment, the inner coating layer 2 is a fragile portion where aluminum or the like in the core material 1 is diffused to form an intermetallic compound. From the point of view, it is better to be as thin as possible, and usually it is desirable to make it thinner than the outer coating layer 3.

[0013] When the diffusion preventing layer has two coating layers,
It can also be formed on the outer peripheral surface of the inner coating layer 2, and when there are three or more coating layers, it can be provided on at least one of the adjacent surfaces of the coating layer. It is preferably provided on either the outer peripheral surface of the inner coating layer or the inner peripheral surface of the outer adjacent coating layer. Even when the coating layer is made of a titanium alloy, the diffusion prevention layer may be formed by oxidizing a required surface.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a manufacturing method according to the invention;
It is a schematic longitudinal cross-sectional view when the coating layer which consists of layers is united.

FIG. 2 is an enlarged schematic cross-sectional view taken along line II-II of FIG.

FIG. 3 is a schematic vertical cross-sectional view when a set screw is screwed to both ends of an outer coating layer after the combination shown in FIG. 1;

FIG. 4 is a graph showing a hardness distribution in a cross section of a wire as a product.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Core material, 2 ... 1st (inside) coating layer, 3 ... 2nd (outside) coating layer, 3a ... Diffusion prevention layer (oxide film).

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location G02C 13/00 G02C 13/00

Claims (4)

(57) [Claims] 1. A core material made of aluminum or an aluminum alloy is covered with a plurality of coating layers made of titanium or a titanium alloy, and at least one of adjacent surfaces of the coating layer is coated with the aluminum. Alternatively, a method for producing a titanium-clad-aluminum wire material, comprising providing a diffusion prevention layer for an aluminum alloy. 2. The coating layer is formed from a first coating layer adjacent to the outside of the core material and a second coating layer adjacent to the outside of the coating layer, and the diffusion preventing layer is The first
2. The method for producing a titanium-clad-aluminum wire material according to claim 1, wherein at least one of the outer surface of the coating layer and the inner surface of the second coating layer is provided. 3. The production of a titanium-clad-aluminum wire material according to claim 2, wherein the thickness of the first coating layer is smaller than the thickness of the second coating layer. Method. 4. The method for producing a titanium-clad-aluminum wire material according to claim 1, wherein the diffusion preventing layer is formed by oxidizing the surface of the coating layer.