JPS6024285A - Production of pipe-shaped clad material - Google Patents

Abstract

PURPOSE:To obtain a pipe-shaped clad material by fitting an inside pipe into an output pipe and heating the pipes under the static pressure exerted thereto from the space in the inside pipe or the outside space of the outside pipe thereby joining diffusively the inside and outside pipes. CONSTITUTION:A ceramic 7 to be formed as an inside layer is made to a prescribed size and a metal 8 to be formed as an outside layer is so manufactured as to project from both ends of the ceramic 7 in order to provide caps 12 for pressurizing a space 11 to serve as a pressurizing part. The outside of the ceramic 7 in contact with the metal 8 is subjected to a surface treatment 9. The metal 8 is so combined with the ceramic 7 as to project above and below therefrom and an outside cylinder 10 for pressurization is so set on the outside of the metal 8 as to enable pressurization of the space 11 by a pressure medium. The caps 12 are attached to the top and bottom parts of the space 11 and the pressure medium is supplied into the space through a gas feed hole 15 to maintain the pressure. A packing material 13 is packed to the inside of the ceramic 7. The assembly is heated in a vacuum atmosphere while the space 11 is kept pressurized to accomplish diffusion joining. The assembly is cooled upon completion of the pressurization. The material 13 of the ceramic 7 and the outside cylinder for pressurization on the outside of the metal 8 are removed. The top and bottom of the metal 8 are machined away to the position of the ceramic 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a pipe-shaped cladding material, and relates to a method for manufacturing a pipe-shaped cladding material. The present invention aims to provide a method for cladding even brittle pipe-shaped materials by diffusion bonding under static pressure.

There are the following methods for manufacturing pipe-shaped cladding materials.

(1) - Cleaning This explosive bonding method includes an outer tube drive method and an inner tube drive method.

The feature of this method is that the pipe to be joined and the pipe to be joined are joined by impacting the pipe to be joined against the pipe to be joined in a very short period of time using the explosive force of gunpowder. FIG. 1 shows an overview of the progress of explosive bonding from the outside in a method for manufacturing pipe-shaped cladding materials using an external tube drive method. A person sets an explosive on the outside before detonation, detonates a B grade explosive, and the inner tube and outer tube are #
The state in which explosive bonding has been completed up to the center of 1#E and the state in which explosive bonding in C#''i has been completed is shown. Fig. 2 shows an outline of the inner tube drive system in which explosives are filled into the inner tube and explosive bonding is carried out from the inside.

In FIGS. 1 and 2, 1Fi is the inner tube, 2 is the outer tube, and 3 is the explosive that causes the inner tube 1 and the outer tube 2 to explode.

4 indicates a detonator for igniting the explosive 3.

5 is a filling, 6F'i void, and 7 is an eel preservation tube.

For example, a case will be described in which a pipe-shaped cladding material is manufactured using the outer tube drive method. The inner tube 1 is filled with a filler 5, a gap 6 is provided outside the inner tube 1, and the outer tube 2 is set.

An explosive 5 and a detonator 4 are set on the outside and upper part of the outer tube 2.

The explosive 3 is ignited by the detonator 4, and the inner tube of the tube to be welded and the outer tube 2 of the IK jointed tube are explosively bonded. The state of completed explosive bonding is shown in FIG. 1-Cr, but since the explosive force of explosives is used to impact the bond, it is not possible to bond materials that are weak against impact, such as ceramics. Further, since the pipes to be joined undergo large deformation during joining, the pipes to be joined are limited to materials having ductility. In addition, in order to strengthen the impact force, it is necessary to provide a gap between the pipes to be joined and the pipes to be joined, and for this reason, the explosion bonding method cannot join three or more pipes at once. (2) Drawing method (rolling) (Variation) The feature of this method is that multiple pipes are joined by drawing.

Figure 3 shows the joining state of pipe-shaped cladding materials by the drawing method. 0 1.2Vi pipes to be joined, 3 a drawing die, 4
Fi filling sand is shown.

By passing the pipe 1.2 through the die 3, the pipe diameter decreases from A to B. During this diameter reduction process, pipes 1 and 2
are joined by receiving compressive force from the outside and inside, respectively.

However, this method has the disadvantage that it is limited to joining materials that are easily plastically deformed.

(3) Overlay method The feature of this method is that overlay welding is performed on one piece of the pipe base material.

Figure 4 shows the state of joining of pipe-shaped rad holes using this construction method. AJ′i is the inner surface build-up method, and B is the outer surface build-up method. 1 indicates the material pipe, and 2 indicates the overlay layer.

However, this method has the drawback that the combinations of base metals and welding materials are limited, and it is difficult to perform internal overlay welding of small-diameter pipes.

(4) Casting method This is a method of pouring molten metal into the inside or outside of a pipe and then machining it to create a pipe-shaped cladding material.

FIG. 5 shows a method of manufacturing a pipe-shaped cladding material by a casting method. A is an inside casting method, and B is an outside casting method.

1 indicates a material pipe. When casting clad material inside, pour molten metal into the inside of pipe 1. When casting clad material on the outside, molten metal is poured between the mold 3 and the pipe 1.

However, this method has the disadvantage that it cannot be used for brittle materials because the combinations of base material and cast material are limited and the thermal shock is large.

Therefore, as a result of intensive research to develop a method for cladding even brittle pipe-shaped materials, the inventors of the present invention found that when producing pipe-shaped cladding materials, the inner tube was designed to minimize the gap between the outer tube and the inner tube. We have found that it is useful to fit the tube into the outer tube and heat it at high temperature under static pressure to perform diffusion bonding (or eutectic diffusion bonding), and based on this, we have completed the present invention.

That is, in the production of pipe-shaped cladding made of multiple materials by diffusion bonding, the present invention involves fitting an inner tube, which is a raw material for the cladding, into an outer tube, which is a raw material for the cladding. Also, applying a pressure medium to one or both of the external spaces of the outer tube to apply static pressure and heating to a high temperature in a vacuum or a non-oxidizing atmosphere to diffusion bond the inner tube and the outer tube. This is a method for producing a pipe-shaped cladding material.

The pressure medium referred to in the present invention refers to a fluid, and may be either an inert gas or a liquid. Further, diffusion bonding means both solid phase diffusion bonding and liquid phase diffusion bonding (eg, eutectic diffusion bonding).

The diffusion bonding of the present invention can be performed by heating while applying static pressure from the inner space of the inner tube or the outer space of the outer tube, but static pressure from only one side causes tensile stress to act on the tube material. Preferably, static pressure is applied from both the inner tube space and the outer tube outer space. Applying static pressure from both sides in this way has the effect of allowing a considerable amount of stress to be applied to the joint surface of the clad pipe without worrying about deformation or cracking of the pipe material.

In addition, to facilitate diffusion bonding, it is possible to fill the inner space of the inner tube with a filler and apply static pressure from the outer space of the outer tube. It is also possible to provide an outer tube with a large inner diameter, fill the space between the outer tube and the outer tube with a filler, and apply static pressure to the inner space of the inner tube.

The present invention will be described in more detail below, but the present invention is applicable to the fabrication of tubular cladding of any material, including ceramic and metal tubular cladding, brittle metal-on-metal cladding.

Further, the filler used as necessary in the present invention is preferably heat-resistant particles such as silica sand.

Hereinafter, a specific example of manufacturing a pipe-shaped cladding material by joining a ceramic material and a metal such as nickel will be explained based on FIGS. 6A-D and 7E-H.

A-DYi in FIG. 6 shows a procedure for joining ceramic to the inner layer and metal to the outer layer. In addition, metal is included in the inner layer in E to H in Fig. 7.
The procedure for bonding ceramic to the outer layer is shown.

In Figures 6 and 7, 7 is the inner layer in Figure 6 and 7 in Figure 7? J The ceramic material that becomes the outer layer is a metal such as nickel, which becomes the outer layer in FIG. 6 and the inner layer in FIG. 7. Reference numeral 9 indicates a surface treatment such as metallization performed on the outer or inner surface of the ceramic 7; 10 indicates a pressurizing cylinder, such as a pipe, provided outside the space 11 which becomes the pressurizing section shown in FIG. 6; and 11) indicates a vacuum A space which becomes a pressure part for joining the tl ceramic and metal 8 which are pressurized by heating, 12 is a pressure lid provided above and below the space 11 which becomes a pressure part, 13i, i filling, 14 is FIG. In the protective outer cylinder shown in , 15 is an air supply hole for the pressure medium.

To explain the specific example of FIGS. 6A to 6D, as shown in FIG. Therefore, it is manufactured so that it protrudes from both ends of the ceramic 7.

The gap when the ceramic 7 and metal 8 are fitted is minimized.

The outer surface of the ceramic 7 in contact with the metal 8 is subjected to surface treatment 9 such as metallization to improve wettability with the metal 8.

Figure B shows the state of surface treatment.

Next, the metal 8 is assembled so as to protrude above and below the ceramic 7, and the pressurizing outer cylinder 10 is set on the outside of the metal 8 so that the space 11 which becomes the pressurizing part can be pressurized with a pressure medium. Pressurizing lids 12 are attached to the upper and lower parts of the space 11 serving as the pressurizing section, and pressure medium from the compressor is supplied through the air supply hole 15 to maintain the pressure. Inside the ceramic 7, there is a filling 1.
Figure 3 shows the state before joining.

Next, while the space 11 serving as the pressurizing section is pressurized, heating is performed in a vacuum atmosphere (not shown) to perform diffusion bonding. In the case of eutectic diffusion bonding, plating or insert metal is placed on the bonding surface in advance.

After the pressurization is completed, the filler 13 filled inside the ceramic 7 and the pressurizing outer cylinder outside the metal 8 are removed,
For example, the top and bottom of the metal 8 are scraped down to the position of the ceramic 7, and diffusion bonding is completed in the state shown in Fig. D.

To explain E-H in Fig. 7, as shown in Fig. E, the outer layer ceramic 7 is made to a predetermined size, and the inner layer metal 8 is provided with a pressurizing lid 12 for the space 11 which becomes the pressurizing part. It is manufactured so that it protrudes from both ends of the ceramic 70. The inner surface of the ceramic 7 is subjected to surface treatment 9 such as metallization as shown in Figure F.

Next, cover the inside of the ceramic 7, that is, the space 11 that becomes the pressurizing part, with a lid 12 with an air hole 15 opened so that the space 11 can be pressurized.
A filler 13 is filled on the outside of the cellar 2 shell 7, and a protective outer cylinder 14 is provided. Figure G shows the combined state. Next, heating is performed in a vacuum atmosphere (not shown) while pressurizing the space 11 serving as a pressurizing section inside the metal 8, thereby diffusion bonding the ceramic 7 and the metal 8. Pressure jig after cooling and protective outer cylinder 1
4. The filler 13 is removed, and the upper and lower parts of the metal 8 are scraped off to the position of the ceramic 7, and the diffusion bonding is completed in the state shown in Fig. 9H.

Although only diffusion bonding has been described as an embodiment of the present invention, eutectic diffusion bonding can also be performed by plating or insert metal on the bonding surface in advance, and the present invention can be applied to any metal.

In addition, in FIGS. 6 and 7, it has been explained that pressure medium is supplied to 11 and filler is filled to 13, but 11
13 may be filled with a filler and pressure medium may be fed to 13, or both may be filled with pressure medium.

In such a case, an air supply hole 15 is naturally provided in each lid portion so that pressure medium, which is an inert medium, from the compressor can be supplied. Furthermore, in FIGS. 6 and 7, the pressure outer tube 10° and the protective outer tube 14 are provided, but if the inner tube is thick and rigid, the pressure applied to the inner space of the inner tube will be reduced. These are not essential as pressure is also applied from the outer tube to the inner tube due to the reaction, and the fitted body of ceramic 7 and metal 8 is placed directly in a high temperature container in a non-oxidizing atmosphere. can also fully achieve its purpose.

As an exception pipe, scratch 60m, inner diameter 50w+1. Length 1.
000mm carbon 1 steel pipe, outer diameter 50**+*, inner diameter 4
An oxygen-free copper steel pipe (inner pipe) of 5 mm and length 1100III+1 was fitted.

If the pressure required for the inner tube (copper) to plastically deform is Pc, then Pc = σ5tn (b/a) σ8; Yield stress of copper (yield stress of copper at 900°C is approximately 1 kg/key 2) a; 45 yen/2 for the tube radius) b; Vi5om/2 for the inner tube outer diameter) Therefore, 0.1 kg in Pc/10 kg in 2 tubes/2.

Also, the pressure required to join steel and copper is s at 900°C.
kcg/cm" is sufficient, so in this case 15
kg/an” (10 kg/crn” + 5 kg/
If there is a pressure of cn+"), the outer tube and the inner tube can be sufficiently diffusion bonded.

The fitting tube was placed in a furnace at 900°C under an inert gas atmosphere, and an inert gas (Ar) was applied to the inner wall of the inner tube for 15 minutes with an inert gas (Ar) applied to the inner wall of the inner tube. ~60
After holding for a minute, the inner tube and outer tube were fully bonded by diffusion.

The present invention has the following effects.

(1) Shivive-like cladding materials can be manufactured statically by applying pressure, heating, and controlling the atmosphere at the joint.

(2) Since the pipe-shaped cladding material can be manufactured statically, it becomes possible to manufacture the pipe-shaped cladding material by combining a brittle material such as ceramic and metal.

(3) By adjusting the optimum temperature for diffusion bonding, it becomes possible to bond three or more layers of pipes at once.

(4) It is also possible to manufacture pipe-shaped cladding materials by combining metals.

[Brief explanation of drawings]

Figures 1 to 5 explain the manufacturing method of pipe-shaped cladding materials using conventional methods. Figure 5 shows the casting method, and Figures 6 and 7 are diagrams explaining embodiments of the diffusion bonding method of the present invention. Narrow

Claims (1)

[Claims] In manufacturing pipe-shaped cladding materials made of multiple materials by diffusion bonding, the inner tube, which is the raw material for the cladding, is fitted to the outer tube, which is the raw material for the cladding, and the inner tube space of the inner tube and the outer tube outer space are The inner tube and the outer tube are diffusion bonded by applying static pressure to one or both of them by applying a pressure medium and heating them to a high temperature in a vacuum or a non-oxidizing atmosphere. Manufacturing method for pipe-shaped cladding material.