JPH06344022A - Production of composite wire - Google Patents

Abstract

PURPOSE:To obviate the generation of blister and to obtain the composite wire having sufficient joint strength by sealing one side of a pipe material, inserting a core material therein and subjecting the material to hot working under vacuum evacuation. CONSTITUTION:One side of a pipe which is a sheath material is sealed by welding, etc., and a bar material which is the core material is inserted therein. While the pipe is subjected to vacuum evacuation from the side opposite to the sealed end of the pipe, the pipe is subjected to hot working, such as hot swaging or hot drawing. The pipe is drawn at cold. For example one side of a Pt pipe having a 5.2mm outside diameter is sealed by welding and is unevenly tightened. The core material of 52wt.% FeNi having 4.7mm outside diameter is thereafter inserted into the Pt pipe subjected to the degreasing with the alkali and the washing with the alcohol. The inside of the Pt pipe is maintained under 5X10<-3>Torr and thereafter, the pipe is worked in 6 passes down to 2.75mm outside diameter by the hot swager. This pipe is then drawn down to 1.0mm outside diameter at cold. As a result, the intrusion of a lubricant, air and gases into the pipe during drawing does not arise and the oxidation by hot working does not arise and, therefore, intensive working is possible. The workability and productivity are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a composite wire used for a lead wire of a sensor or the like.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a composite wire, a metal billet material as a core material is inserted and compounded with a metal pipe material as a jacket material, and this is extruded by an extruder.
A composite wire rod is obtained by wire drawing, or a metal rod material that is a core material is inserted and compounded with a metal pipe material that is a jacket material, and drawing and annealing are repeated to obtain a composite wire material. However, in the case of extrusion processing, depending on the type of metal, for example, in the case of W, Mo, and FeNi alloys, which have strong high-temperature strength, extrusion may be extremely difficult due to clogging and stable production may not be possible. Further, in the method of repeating drawing and annealing, it was not possible to obtain the one having sufficient composite strength due to the fact that the wire drawing lubricant entered the composite part during the processing and the entry of air and gas. Furthermore, due to the difference in workability (spreadability) between the jacket material and the core material, peeling occurs during wire drawing.
Since cracking and disconnection occurred, strong working was not possible, and the number of heat treatment steps increased, resulting in poor workability and productivity.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned actual circumstances of the prior art, and its object is to manufacture a composite wire having sufficient and stable joining strength and good workability and productivity. It provides a method.

[0004]

According to the method of manufacturing a composite wire of the present invention, one side of a pipe material as a jacket material is sealed, a rod material as a core material is then inserted, and a vacuum is applied from the opposite side to the sealed side. It is characterized by performing hot working such as hot swaging or hot wire drawing while pulling.

[0005]

According to the method of manufacturing a composite wire of the present invention configured as described above, one side is sealed and a vacuum is drawn.
Since no lubricant, air, or gas enters during wire drawing, and it does not oxidize even during hot working, strong working is possible, the number of man-hours is small, and workability and productivity are good.

[0006]

EXAMPLES Examples and conventional examples will be described below. First, as an example, outer diameter 5.2 mm, inner diameter 4.8 mm, length 500 mm
After one side of the Pt pipe of No. 2 was sealed by welding and tightened, a vacuum leak test confirmed that the tightening was complete. After that, the Pt pipe that had been alkali-degreased and alcohol-cleaned had the same outer diameter that was alkali-degreased and alcohol-cleaned
A FeNi 52 wt% core material having a length of 4.7 mm and a length of 500 mm was inserted. Then, a vacuum hose was fitted on the opposite side, the degree of vacuum in the Pt pipe was adjusted to 5 × 10 ⁻³ Torr by a vacuum pump, and then processing was performed with a hot swager to an outer diameter of 2.75 mm in 6 passes. At this time, the material temperature was heated by a burner so as to maintain it at 700 to 800 ° C. Then, the vacuum hose was removed, and then cold drawing was performed to an outer diameter of 1.0 mm. In addition, as a conventional example, after inserting a core material of FeNi52 wt% into the same Pt pipe as in the embodiment, the outer diameter is kept cold.
Wire drawing to 4.5 mm, then heat treatment (diffusion annealing) in a hydrogen atmosphere at 700 ° C for 1 hour, and then the outer diameter
Wire drawing is performed in the cold to 3.9 mm, then heat treatment is performed under the above conditions, and then the processing rate (reduction rate) is 20 to 25
% Wire drawing and heat treatment at a temperature of 700 ° C. for 1 to 0.5 hours were repeated to obtain an outer diameter of 1.0 mm. However, the temperature is 800 ℃,
As a result of performing a blistering test under the condition of a time of 30 minutes, in the example, there was no blistering, and as a result of confirming the joint portion in the cross section, a diffusion layer was also confirmed, and sufficient joint strength was obtained. However, in the conventional example, several blisters were generated. When the blistering portion was analyzed by EPMA, it was found that C and O were detected, and that the lubricant injection and oxidation proceeded.

[0007]

As described above, according to the method for manufacturing a composite wire of the present invention, since hot working such as hot swaging or hot wire drawing is performed while vacuuming is performed, no blistering occurs and the bonding strength is high. In addition to obtaining a sufficient composite wire, it has an excellent effect that the number of working steps can be greatly reduced without repeatedly performing wire drawing and annealing.

Claims (1)

[Claims] 1. A pipe material, which is a jacket material, is sealed on one side,
Then, after inserting a rod material to be a core material, while performing vacuum drawing from the side opposite to the sealed side, hot working of hot swager or hot wire drawing is performed. .