JPH04279212A - Manufacture of fine wire of titanium or its alloys - Google Patents

Abstract

PURPOSE:To provide a process manufacturing fine wire of titanium wherein the manufacturing process is simpler and the manufacturing time is shorter than the prior art of fine wire of titanium or its alloys (hereinafter called Ti) and in addition, much quantities of necessary degreasing solvent and pickling solution can be reduced. CONSTITUTION:A manufacture of fine wire of Ti characterized by obtaining the fine wire of Ti through removal of copper from this fine copper clad wire after the Ti wire is clad with copper to make copper clad wire then wire drawing and annealing are repeated to make this copper clad wire finer.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for producing fine wire made of titanium or titanium alloy, and in particular, it is lightweight and has excellent corrosion resistance, and is used in the chemical industry, marine-related filters, wire mesh, and plastics for sports-related products. The present invention relates to a method for manufacturing a fine wire or ultra-fine wire (hereinafter referred to as thin wire) of titanium or titanium alloy (hereinafter referred to as Ti) suitable for use as a reinforcing material or the like.

0002

BACKGROUND OF THE INVENTION Generally, thin Ti wires are manufactured using Φ5.
The Ti wire is hot-rolled to a thickness of about 5 to 15 mm and subjected to degreasing, pickling, annealing, and wire drawing repeatedly in this order to thin the Ti wire.

[0003] In the production of the above-mentioned thin wire, degreasing is performed to improve the surface wettability during the subsequent pickling, and is carried out by immersing the Ti wire in an organic solvent, etc.
The time required for degreasing is about 30 minutes. The first pickling is to remove the oxidized scale on the surface of the Ti wire, and the second and subsequent picklings are performed to remove the defective oxide film that remains after being destroyed during the wire drawing process. The pickling time is about 20 to 60 minutes.

[0004] Annealing is performed to soften the Ti wire hardened by wire drawing and to form a good oxide film on the surface of the Ti wire to provide lubricity. In a mixed gas atmosphere
This is carried out by heating at 700° C. for about 2 hours. Note that Ti is a metal that easily adheres, and adhesion tends to occur on the die surface even during wire drawing, but if an appropriate oxide film is formed on the Ti surface, the oxide film prevents adhesion and also prevents oil etc. This serves as a carrier for the lubricant, allowing for proper wire drawing. On the contrary, if such an oxide film is not formed, Ti will adhere to the die during wire drawing, making wire drawing impossible. Therefore, the above-mentioned oxide film formation is essential.

[0005] Wire drawing is a process in which the wire is passed through a plurality of dies with different hole diameters to reduce the cross-sectional area of the wire and make the wire thinner, and the cross-sectional area reduction rate per die is approximately 10 to 1.
5%, and the total cross-sectional area reduction rate per wire drawing process (per wire drawing process performed after annealing and before degreasing) is at most 50 to 70% in the case of titanium, and about 70% in the case of titanium alloys. Maximum 30
It is limited to about 50%. This is because the oxide film is brittle and has poor adhesion, so if the wire is drawn to the above-mentioned total cross-sectional area reduction rate, the good oxide film that provides lubricity will be destroyed and the lubricity will deteriorate; This is because line processing becomes impossible.

[0006]

Problems to be Solved by the Invention As described above, since the oxide film is destroyed and the lubricity deteriorates, the total cross-sectional area reduction rate per wire drawing process is limited as described above. Therefore, in the conventional method for producing thin Ti wires, it is necessary to repeatedly perform degreasing, pickling, annealing, and wire drawing, which makes the production process complicated and takes a long time. There is a problem in that large amounts of degreasing solvents such as and pickling solutions such as nitric-fluoric acid are required. These are serious problems that lead to increased production costs and deterioration of environmental health.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to simplify the manufacturing process and shorten the manufacturing time as compared to the conventional method for manufacturing thin Ti wires. The present invention aims to provide a method for producing thin Ti wires that requires less degreasing solvent and pickling solution.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the method for producing a thin wire (i.e., a thin wire or an ultrafine wire) of Ti (i.e., titanium or titanium alloy) according to the present invention has the following configuration. .

That is, in the manufacturing method according to claim 1, a wire made of Ti is coated with copper to form a copper-coated wire, and then the copper-coated wire is thinned by repeated wire drawing and annealing. , by removing copper from the thinned copper-coated wire material,
This is a method for producing a thin wire of Ti, which is characterized by obtaining a thin wire made of i.

[0010] The manufacturing method according to claim 2 is characterized in that the thickness of the copper in the copper-covered wire material before the wire drawing process is 3 μm or more, and the ratio of the cross-sectional area of the copper to the cross-sectional area of the wire is 60% or less. Item 1 is a method for producing a thin Ti wire. In the manufacturing method according to claim 3, the copper-coated wire is annealed at 600 to 850°C in the form of a strand.
3. The method for producing a thin Ti wire according to claim 1 or 2, wherein the method is carried out by heating for 10 seconds to 10 minutes. Also, claim 4
The described manufacturing method includes Ti obtained after removing the copper.
Claim 1: The thin wire is further drawn into a thin wire.
, 2 or 3 is a method for producing a thin Ti wire. The manufacturing method according to claim 5 is the method for manufacturing a thin Ti wire according to claim 4, wherein the processing rate of the wire drawing after the copper removal is 5 to 70%.

[0011]

[Function] The method for producing a thin Ti wire according to the present invention is
A wire rod consisting of i is coated with copper to form a copper-covered wire rod, and then the copper-covered wire rod is repeatedly subjected to wire drawing and annealing to thin the copper-covered wire rod, and then copper is removed from the thinned copper-covered wire rod. An attempt is made to obtain a thin wire made of Ti.

[0012] In the wire drawing process of the copper-coated wire rod, Ti
The wire is processed together with the copper on the surface layer, and the entire copper-coated wire becomes thinner, and the Ti wire becomes thinner. At this time, the surface copper has excellent lubricity and is a metal that is very difficult to adhere to, so diamond dice,
It is extremely unlikely to adhere to dies such as sintered diamond dies and alloy dies, and can also serve as a carrier for lubricants such as oil. Further, since copper has excellent ductility and excellent adhesion to the base material and does not break, the lubricity hardly deteriorates. Therefore, compared to the conventional method, the cross-sectional area reduction rate per die can be increased, and the total cross-sectional area reduction rate per wire drawing process can be increased, so that the required Ti thin wire can be obtained. The number of repetitions of wire drawing and annealing required up to this point can be reduced.

Further, copper can be easily removed from the thinned copper-coated wire by pickling or electrolytic polishing, and only needs to be done once. In addition, if the Ti wire to be subjected to the first wire drawing process is hot-rolled, it needs to be pickled to remove oxide scale, but pickling is not necessary in the subsequent steps except for the above-mentioned pickling to remove copper. It is. It is necessary to coat the Ti wire with copper, but this only needs to be done once.
The effect of reducing the number of times of pickling, wire drawing, and annealing is significant, and the overall number of processes is significantly reduced.

Therefore, according to the method for manufacturing a thin Ti wire according to the present invention, compared to the conventional method for manufacturing a thin Ti wire,
The manufacturing process is simple and the manufacturing time is short, and
A small amount of pickling solution is required, and furthermore, a degreasing solvent is almost unnecessary. As a result, manufacturing costs can be reduced and environmental hygiene can be improved.

[0015] In addition to copper, there are other metals that are difficult to adhere to.
Copper was used as the coating material for the Ti wire because copper is the most difficult metal to adhere to, has excellent ductility, and is difficult to work harden.
This is because it is easy to coat Ti, it does not melt at the softening temperature of Ti during annealing after wire drawing, and furthermore, the coating layer is easy to remove at the final stage and has excellent recoverability. .

[0016] When the thickness of the copper in the copper-covered wire material before the wire drawing process is set to 3 μm or more, and the ratio of the cross-sectional area of the copper to the cross-sectional area of the wire is set to 60% or less, the wire drawing process can be performed reliably and stably. It's good because I get it. Note that if the thickness is less than 3 μm, the Ti wire will be locally exposed and difficult to wire draw when the total cross-sectional area reduction rate is 30% or more. If the cross-sectional area ratio exceeds 60%, the copper of the coating layer will be processed preferentially, making it difficult to draw the Ti wire, which may cause so-called cuppy wire breakage.

[0017] The copper-coated wire is annealed at 600 to 850°C for 10 seconds to 1 hour in the form of a strand.
If heating is performed for 0 minutes, a wire drawing inhibiting alloy layer will not be formed at the interface between the Ti wire and the copper of the coating layer, so it is desirable to do so. In addition, if the temperature exceeds 850°C and/or exceeds 10 minutes, an alloy layer that inhibits wire drawing will be formed.
If it is less than 0°C, Ti cannot be softened very much, and if it is less than 10 seconds, there will be variations in the heating rate of the wire and some parts will not be softened, making it difficult to draw the wire. If the time exceeds 10 minutes, productivity will also decrease. The reason for using the strand state is that the annealing conditions can be strictly controlled. The atmosphere during annealing is not particularly limited, but it is preferable to use a non-oxidizing gas such as argon or nitrogen, or a reducing gas containing hydrogen.

[0018] The Ti thin wire obtained after removing the copper may be further drawn (additional wire drawing) to be thinned to a required diameter, and the additional wire drawing improves dimensional accuracy and surface smoothness. It has an effect. After removing copper, the surface of the Ti wire is not directly restrained by the die during wire drawing, so there are minute irregularities on the Ti surface, and the surface is smoother than that of wire drawn without copper coating. The properties and dimensional accuracy are slightly inferior. Such unevenness is effective in improving adhesion to plastic when the Ti thin wire is used as a plastic reinforcing material, and is effective in improving filtration performance when used in a filter. However, there are cases where dimensional accuracy is required, and there are cases where surface smoothness is required, such as when the material is subjected to processing that passes through many guides, such as wire mesh forming. In such a case, the additional wire drawing process described above is effective. At this time, the processing rate of the additional wire drawing process is preferably 5 to 70%; if it is less than 5%, the effect of improving dimensional accuracy etc. will be small, and if it exceeds 70%, it will be difficult to properly perform the additional wire drawing process. For lubrication during additional wire drawing, the use of molybdenum disulfide is sufficient if the processing rate is approximately 20% or less, but if the processing rate is higher than that, it is necessary to form an oxide film on the surface of the Ti thin wire.

[0019] As for the copper removal treatment, it is preferable to use an electrolytic method rather than a pickling method because the treatment is easier and the workability is excellent, and the copper can be easily recovered. For example, a neutral salt such as sodium sulfate, sulfuric acid, or the like may be used as the electrolyte, and neutral salts are advantageous in terms of environmental hygiene and can be easily turned into sludge. Copper can be recovered by reverse electrolysis using dilute sulfuric acid.

[0020]

[Example] (Example 1) Φ5.5 surface scratch removed
A Ti wire made of pure titanium with a diameter of 8 mm was exposed to triclene vapor for 30 minutes to be vapor degreased, then made into a strand, annealed by heating at 700°C for 3 minutes in an argon (Ar) stream, and then made into a strand with an outer diameter of 8 mm. The wire was inserted into a copper tube with a thickness of 0.6 mm, and drawn in close contact to produce a copper-clad Ti wire (copper-clad wire) with a diameter of 6.7 mm.

[0021] The copper-coated wire rod was drawn to a diameter of Φ1.22 mm at a cross-sectional area reduction rate of 12 to 20% per die, and then formed into a strand and heated at 700°C in an Ar air flow.
It was annealed by heating for 2 minutes. Next, the wire was drawn to a diameter of 0.2 mm by the same method as above, annealed at 650°C for 2 minutes, and then drawn to a diameter of 0.097 mm. Next, this was electrolyzed in 15% sulfuric acid to remove copper, and Φ0.0
A thin Ti wire of 80 mm was obtained. Incidentally, powdered calcium soap was used as the lubricant for the wire drawing process.

(Comparative Example 1) After degreasing the same Ti wire as in Example 1 by the same method, oxygen:
The wire was annealed by heating at 700° C. for 2 hours in a mixed gas of 10% Ar and the remainder Ar, and then wire-drawn to Φ3.1 mm at a cross-sectional area reduction rate of 7 to 15% per die.

The drawn wire material was degreased by the same method as above, pickled with a mixed acid of 40% nitric acid and 5% hydrofluoric acid, washed with water,
After drying and annealing under the same conditions as above, the wire was drawn to a diameter of 1.76 mm in the same manner as above. Next, degreasing, pickling, annealing, and wire drawing were performed in the same manner as above.
After repeating this process several times to obtain a thin Ti wire with a diameter of 0.080 mm, it was degreased and pickled. Incidentally, molybdenum disulfide was used as a lubricant for the wire drawing process.

(Example 2) Φ5.
An 8 mm Ti wire made of titanium alloy (Ti-6Al-4V) was degreased and annealed in the same manner as in Example 1, then inserted into the same copper tube and closely drawn to a diameter of 7.0 mm.
Copper-coated wire material was made. Cross-sectional area reduction rate per die of this copper-coated wire material: 10
The wire was drawn to a diameter of Φ4.39 mm at ~18%, and the strand was annealed by heating at 700° C. for 2 minutes in an Ar flow. Next, by the same method as above, wire drawing and annealing up to Φ2.67 mm, wire drawing and annealing up to Φ1.63 mm, wire drawing and annealing up to Φ1.
Wire drawing and annealing to 0.01mm, and further Φ0.609
The wire was drawn to a length of mm. Next, this was subjected to copper removal treatment in the same manner as in Example 1 to obtain a Ti thin wire with a diameter of 0.500 mm.

(Comparative Example 2) After degreasing and annealing the same Ti wire as in Example 2 in the same manner as in Comparative Example 1, the cross-sectional area reduction rate per die was Φ4.93 m with a reduction rate of 6 to 14%.
The wire was drawn to m. This was done in the same manner as in Comparative Example 1.
Degreasing, pickling, annealing, and wire drawing to Φ4.20mm, and then repeating degreasing, pickling, annealing, and wire drawing 13 times to obtain Φ0.
．． After obtaining a 500 mm 2 thin Ti wire, it was degreased and pickled.

In the above example, the number of degreasing times a, the number of pickling times b, the number of annealing times c, the number of wire drawings n (number of wire drawings per one wire drawing process d x the number of wire drawing processes e=n), the number of times of copper removal Number of times f, N=
a+b+c+n+f is a=8, b in Comparative Example 1
=7, c=7, n=52, f=0, N=74, whereas in the case of Example 1, a=1, b=0,
c=3, n=45, f=1, N=50, and the total number of steps is extremely small. In the case of Comparative Example 2, a=15, b=
14, c=14, n=30, f=0, N=73, whereas in the case of Example 2, a=1, b=0, c
=4, n=26, f=1, N=32, and the total number of steps is extremely small.

(Example 3) A copper coated wire drawn to a diameter of 0.185 mm was prepared in the same manner as in Example 1, and then the copper was removed in the same manner to obtain a thin Ti wire with a diameter of 0.152 mm. Next, the wire was annealed by heating at 700°C for 2 minutes in a mixed gas flow of 25% oxygen and Ar as the balance to form an oxide film on the surface of the Ti thin wire, followed by lubricant: molybdenum disulfide and one die. Cross-sectional area reduction rate: 11
~15% wire drawing process, Φ0.100mm Ti
Got a thin line. The dimensional accuracy and surface smoothness of the Ti thin wire were comparable to those made by the prior art.

(Example 4) A copper coated wire was produced by drawing the wire to a diameter of 0.129 mm in the same manner as in Example 1, and then the copper was removed in the same manner to obtain a thin Ti wire with a diameter of 0.105 mm. . Next, wire drawing was carried out under the conditions of lubricant: molybdenum disulfide to obtain a thin Ti wire with a diameter of 0.100 mm. Although the surface smoothness of the Ti thin wire was inferior to that made by the prior art, the dimensional accuracy was the same.

[0029]

Effects of the Invention The method for producing a thin wire (thin wire or extra-fine wire) of Ti (titanium or titanium alloy) according to the present invention has the above-mentioned structure and functions, and has the following features: Not only can the area reduction rate be increased, but also the total cross-sectional area reduction rate per wire drawing process can be increased, so that the required Ti
The number of repetitions of wire drawing and annealing required to obtain a thin wire is reduced, and the number of times of degreasing and pickling is also significantly reduced, which greatly reduces the total number of steps required to obtain the required thin Ti wire. do. Therefore, compared to the conventional manufacturing method of Ti thin wire, the manufacturing process is simple and the manufacturing time is extremely short, and a small amount of pickling solution is required, and furthermore, there is almost no need for degreasing solvent. As a result, it is possible to reduce manufacturing costs and improve environmental hygiene.

Claims (5)

[Claims] Claim 1: A wire made of titanium or a titanium alloy is coated with copper to form a copper-coated wire, and then the copper-coated wire is thinned by repeated wire drawing and annealing, and then the thinned copper 1. A method for producing a thin wire made of titanium or a titanium alloy, the method comprising removing copper from a coated wire to obtain a thin wire made of titanium or a titanium alloy. 2. The titanium or titanium according to claim 1, wherein the thickness of the copper of the copper-clad wire material before the wire drawing process is 3 μm or more, and the ratio of the cross-sectional area of the copper to the cross-sectional area of the wire is 60% or less. Method for producing fine alloy wire. 3. The thin wire of titanium or titanium alloy according to claim 1 or 2, wherein the copper-coated wire is annealed by heating the copper-coated wire in the form of a strand at 600 to 850°C for 10 seconds to 10 minutes. Production method. 4. The method for producing a fine wire made of titanium or a titanium alloy according to claim 1, wherein the thin wire made of titanium or a titanium alloy obtained after removing the copper is further drawn into a thin wire. 5. The method for producing a fine wire of titanium or titanium alloy according to claim 4, wherein the processing rate of the wire drawing is 5 to 70%.