JPS5857944A - Composite metallic pipe and its manufacture - 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 The present invention relates to a Ni/Ti composite metal tube with excellent vibration-proofing properties and a method for manufacturing the same, and in particular to a Ni/Ti composite metal tube that forms the composite metal tube.
By forming an intermetallic compound between Ti and Ti, it is intended to provide a composite metal tube with excellent pv and vibration properties.

Tubular materials with excellent vibration damping properties (vibration damping ability) are often required in various machines and precision equipment. especially,
This requirement is particularly strong for the metal tube that forms the pickup tone arm that supports the pickup cartridge in the player body. This is because record players are constantly exposed to external vibrations such as blue tatami vibrations from the speakers during performance, and if this is transmitted directly to the cartridge stylus tip through the tone arm, it will naturally impair the mechanical-electrical conversion characteristics of the pickup. . Therefore, the tone arm is required to have vibration-proofing properties that attenuate various external vibrations without transmitting them to the pickup needle tip. In particular, 1. Although metal tubes such as M alloy and bird alloy that are normally used as tone arm materials are generally lightweight and have high rigidity, they often have poor vibration damping properties, and there is a strong demand for improvement.

To deal with this, heat treatment is performed to precipitate chromium carbide at the grain boundaries of a tube material made of powdered sintered compact of 18Cr-8Ni stainless steel, and chemical etching is performed to selectively dissolve the chromium carbide from the inside of this tube material. 2. It has also been proposed to use a stainless steel tube as a tone arm, which has two fine holes formed on its inner surface to improve its vibration damping properties (magazine ``Nikkei Mechanical J19'').
(July 9, 1979 issue). However, although the stainless steel tone arm obtained in this way has excellent vibration-proofing properties, it is heavy due to its material, and due to the increased weight of the tone arm, it is difficult for the record to be transmitted through the stylus tip. There are disadvantages such as an increase in load and an obstacle to miniaturization due to an increase in balance weight to avoid this.

The object of Jin's invention is to provide a metal tube that is lightweight and has excellent vibration damping properties, as well as a method for manufacturing the same, while eliminating the problems of the prior art described above.

The present inventor was in the process of conducting research for the above purpose.

When a bonded body with general kNi & Ti is heat-treated at a temperature of 600"0 or higher, Ni − is generated by diffusion at the boundary.
We focused on the fact that Ti intermetallic compounds have high vibration damping properties. By heat treatment of this stiff Nl/T1 joint, the Le interface KN
The formation of 1-Tl intermetallic compounds is a well-known phenomenon. However, such N1−
The Tl intermetallic compound is mechanically weak <, N1/Tim1
Even though diffusion heat treatment is performed to increase the bonding strength of the composite, if such a brittle Ni-Ti intermetallic compound is generated, the desired increase in bonding strength cannot be obtained, and therefore, there are various measures including temperature conditions. Studies have been conducted to prevent this from occurring. However, in the case of a fitting assembly of N1 pipe material and T1 pipe material as in this invention, the integrity between the two is originally maintained well due to its structure, so the joint strength between the two can be improved. is not so needed. Therefore, for applications requiring excellent vibration damping properties, it is preferable to actively form an intermetallic compound layer between the two. Moreover, the Ni/
Due to the lightness of T1, the Ti composite tube is much lighter than stainless steel or the like.

The vibration-proof composite metal tube of the present invention is based on the above-mentioned knowledge, and more specifically, one of the Nl-based metal tube and the T1-based metal tube is fitted into the other, and a Ni-T1 intermetallic compound layer is formed. They are characterized in that they are joined to each other via.

Further, the method for manufacturing a composite metal tube of the present invention includes inserting one of the Ni-based metal tube and the T1 Go metal tube into the other.

Both are reduced in diameter to obtain a joined tube body, and this tube body is heated to produce N.
1 N1 due to diffusion between base metal tube and T1 base metal tube
-The formation of a T1 intermetallic compound layer is used as an acoustic mold. When forming the Ni-Ti intermetallic compound by this heat treatment, the generated intermetallic compound N1. T1
Due to the Kirkendall effect (a phenomenon in which preferential diffusion occurs from the side with the higher diffusion rate to the other side when diffusion occurs between two layers with different diffusion rates) at the interface between the N1 layer and the N1 layer, minute particles are formed at the interface. A void occurs. The formation of this void has the property of increasing the vibration damping effect. Furthermore, during heat treatment for diffusion, α-T1 becomes stronger than β-T1.
Infiltration is important in providing a composite metal tube that changes to T1 and has excellent strength as a whole.

This invention will be explained in more detail below.

The composite metal tube of the present invention exhibits a schematic laminated structure as shown in FIG. 1, for example. That is, the composite metal tube of this example is formed by laminating in this order the inner layer N1 layer, the intermediate Ni-Tl intermetallic compound layer 2, and the outer layer T1 layer 3. The expanded layer structure of the Tl intermetallic compound layer 2 is as follows.

This is the general arrangement shown in FIG. 2 in the vicinity of As in FIG. 1. That is, the Ni-T1 intermetallic compound layer 2 is microscopically divided into a NiTig layer 2a, a NiTi layer 2b, and a Ni, Ti layer 2c in order from the side in contact with the Ti layer 3, which generally forms β-T1. ,j! N18Ti layer 2c
A microvoid is formed near the boundary 4 between and Nim1 due to the Kirkendall effect. Generally, it is preferable that the thickness of the Ni-TI intermetallic compound layer 2 is 1 mm or more, and in the range of 5 to 30 ts of the total thickness of the composite metal tube. ,
Regarding the laminated tube body obtained by inserting it into a T1 tube having an inner diameter slightly larger than its outer diameter.

The Ni tube and the T1 tube are joined together while reducing the diameter of the entire Ni tube (the outer Ni tube) by a plastic working means capable of maintaining the tube shape as a whole, such as drawing or extrusion. At this time, the degree of diameter reduction depends on the dimensions of the final product, but when comparing the maximum diameters.

It is usually about 5 to 10%. In addition, plastic working is performed either cold or hot, but in order to make the working easier,
It is preferable to perform the range processing at 00 to 600°C.

The N1/T1 jointed tube body obtained as described above is subjected to plastic working (deformation working) to obtain a shape corresponding to the final product shape, if necessary. For example, the tone arm shape may be a straight shape, a loose S-shape, a single-shape, or the like.

According to the present invention, the obtained joined tube body is then subjected to heat treatment to form a Ni-Tll intermetallic compound at the boundary between the Ni layer and the Ti layer by thermal diffusion. These intermetallic compounds are formed at temperatures above 600°C;
A temperature of 650° C. or higher is preferred in order to promote more active production. Further, in order to simultaneously convert Tl into β-Ti, it is necessary to heat the material to a temperature higher than the phase transition temperature of 882°C. Heating time varies depending on the dimensions of the composite metal pipe, but
Outer diameter 10~15u+.

When forming a tone arm having a total wall thickness of 0.5 to 1.0113 mm, it is appropriate to leave the tone arm at a temperature of 650° C. or higher for about 60 to 600 minutes. After heating, the composite metal tube is cooled by furnace cooling, natural cooling, or the like.

In this way, a composite metal tube as shown in FIG. 111 and FIG. 2 is obtained. This composite metal tube also has:

Depending on the use of the final product, for example, in the case of a tone arm, finishing processes such as threading, drilling, plating, etc. are performed as necessary.

In the above, it can be seen that the composite metal tube of the present invention and its advantages are truly appreciated. Some of these modifications will be described below.

First of all, Nl tubes are made only of pure Ni (
Cr, Cu, F@, Ag, Si, S, Pb, Pt, A
)x, rare earth element* T1. Nb, AA'tMo, Sn
, contains one or more types of Co, and the balance is Ni 80% (
Also used is a Ni-based alloy consisting of weight -0 or less, the same applies) or more. In this specification, pure Ni and these Ni-based alloys are collectively referred to as "N1-based metals."

In addition, in place of the TI pipe made of pure Ti, kl, V,
A tube made of a Ti-based alloy containing elements such as Mn, Fe, Cu, MarCr, W, and C, and the balance being Ti 90 or more, is also used. In this specification, pure Ti and these T1
The base alloy is also referred to as "Ti-based metal."

Also, different from the above, an Nl-based metal layer forms the outer layer, and T1
It is also possible to have a configuration in which the base metal layer forms the outer layer. However, because Ni diffuses quickly, voids occur in the N1 layer due to the Kirkendall effect, reducing the strength of the Ni layer, which may result in insufficient strength against external impacts. First, the Tl-based metal layer 3 forms the outer layer.
The layer structure shown in the figure is preferable. However, in addition to the layer structure as shown in Figure jII1, the outermost layer is made of stainless steel such as Ni-containing stainless steel or a N1 base metal layer as described above to improve finishability such as plating and brazing properties. It can also be improved. At this time, if the outermost layer is an N1-containing alloy, the outermost layer and the inner T
An N1-Ti intermetallic compound layer may also be formed between the base metal layer and the base metal layer.

As described above, according to the present invention, Ni-T in the middle
A composite metal tube is provided in which a Ni layer and a T1 layer are bonded via an intermetallic compound layer, and this composite metal tube is lightweight, and the Ni-Ti intermetallic compound layer and the intermetallic compound are bonded together during heat treatment. It has a large vibration damping effect due to the presence of minute voids generated by the Kirkendall effect at the boundary between the Ni layer and the Ni layer. Therefore, by forming a pickup tone arm made of such a composite metal 11, a lightweight and vibration-proof tone arm can be obtained.
Since the balance weight can be made smaller, the entire pickup can be made smaller, and the vibration energy extracted from the tip of the needle can be smoothly converted into electrical energy without being hindered by external vibrations such as acoustic vibrations from speakers. becomes possible. Further, in addition to the heat treatment for forming the Ni-T1 intermetallic compound, T1 becomes β-T1 with excellent strength, and the weight of the tone arm can be further reduced by that strength.

Hereinafter, this invention will be described as an example. This will be explained in detail.

! A Ni '11 with an outer diameter of 15.3 ga and a wall thickness of 0.5 m11 was inserted into a 'Ti tube with an outer diameter of 18 mm and a wall thickness of 0.3 su*, and the resulting laminated tube was heated at 300°C to 3 o OK g/c11.
A joined pipe body having an outer diameter of 15 m and an inner diameter of 13.41111 mm was obtained by extrusion.

Next, heat treatment was performed in a high-purity argon atmosphere in order to form a pNi-Ti intermetallic compound layer on this joint tube by diffusion. The heat treatment was performed by increasing the temperature of the joined tube at a rate of 100°C/hr to 800°C, and thereafter increasing the temperature to 90°C, which is the heat treatment temperature.
Raise the temperature up to 50°C at a rate of 10°C/hr.

Hold at this temperature for 1 hour, then increase to 800°C at 10°C/hr.
The N of this invention can be obtained by cooling in a furnace until
An i/Ti composite tube was obtained.

Results of analysis using an X-ray microanalyzer.

This composite tube includes Ni-Ti with a total thickness of 0.12u+.
An intermetallic compound layer was formed. The hardness distribution in the thickness direction near this boundary layer is summarized together with that before heat treatment,
It is shown in Figure 3. It can also be seen from FIG. 3 that a hard Nl-Ti intermetallic compound layer is formed as a result of the heat treatment.

On the other hand, in the above composite pipe manufacturing process, the heat treatment temperature was set to 7
Regarding the composite tubes obtained by changing the temperature to 00°C, 800°C, 900°C, and 950°C (all for 5 hours), Ni, /”
FIG. 4 is a plot of the hardness at the PL boundary.

Unfortunately, the above operation was repeated for dihydrogen at heat treatment temperatures of 850°C and 950°C, and the heat treatment time was varied from 5 to 20 hours to obtain a Ni/Ti composite tube. The interlayer compound layer thickness and vibration damping rate Q-1 were measured. The results are shown in Figure 5.

The vibration damping rate was measured by applying a cibaric input to the end face of a composite pipe (length 200 m + 11) and detecting the waveform of the output from the opposite end face using a synchroscope.

Looking at FIG. 5, it can be seen that as the heat treatment time increases and the heat treatment temperature increases, the thickness of the Ni-Ti intermetallic compound layer increases, and the effective vibration damping ability increases accordingly.

[Brief explanation of drawings]

Figure jI1 is a sectional view in the pipe diameter direction showing a conceptual laminated structure of a composite metal pipe according to an embodiment of the present invention. Figure JI2 is an enlarged sectional view near section A in Figure 1. Figure JII3 shows the hardness distribution in the thickness direction near the Ni/'f'i boundary of a composite metal, etc. according to an embodiment of the present invention, together with that before heat treatment. Figure 4 shows the hardness distribution of Ni due to changes in heat treatment temperature. Graph showing changes in hardness at the /Ti boundary. FIG. 5 is a graph showing changes in the thickness of the intermetallic compound layer and vibration damping rate due to changes in heat treatment temperature and time. l...Ni layer 2 ・N1-Tin intermetallic compound layer (2a ・=NiT1
m -2b...NiTi, 2c...NtaT port 3...T1 layer @ Applicant's agent Kiyoshi Inomata Figure 4 Figure 5 LfIJ Juku processing center (hv)

Claims (1)

[Claims] 1. Ni! A vibration-proof composite metal tube characterized in that one of a metal tube and a TI-based metal tube is fitted into the other and joined to each other via a Ni-Ti intermetallic compound layer. 2. The composite metal tube of item 1 above, wherein the Ni-based metal tube is inserted into and joined to the Ti-based metal tube. 3. The first above, wherein the joined body of the Ni-based metal tube and the T1-based metal tube is further fitted into the N1-containing alloy tube forming an outer layer.
Composite metal pipe according to item 2 or item 2. 4. After inserting one of the Ni-base metal tube and the T1-base metal tube into the other, 1. Reduce the diameter of both to obtain a tube body, and heat this tube body to create a space between the Ni-base metal tube and the T1-base metal tube. Ni-T
i. A method for manufacturing a composite metal tube, characterized by a layer of metal that forms an intermetallic compound layer. ! 4. The method of item 4 above, wherein the S, Nl-based metal tube has a smaller diameter than the Ti-based metal tube. 611 The method of item 2 or 4 above, which includes the step of deforming the joint tube before heating it.