JPH04272185A - Manufacture of metallic tube equiped with metal-base composite material film - Google Patents

Abstract

PURPOSE:To easily manufacture such a metal tube the inner wall of which is provided with a metal-base composite material film having large film thickness, dense structure and excellent wear resistance. CONSTITUTION:Firstly, an inner cylinder comprising an elastic member such as rubber is disposed in a metallic tube 1, and the space between the metallic tube and the inner cylinder is filled with a mixed powder of metallic powder and ceramic powder and sealed. Then the compacted powder body 3a of the mixted powder is adhesively bonded to the inner wall of the metallic tube 1 by cold hydrostatic pressing, and then the inner cylinder is removed. Then the metallic tube 1 is inserted in a chamber 5, which is then evacuated and selaed. Then the compacted powder body 3a is sintered by hot hydrostatic pressing. By this method, a the metal tube lined with the metal-base composite material can be obtaind.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for manufacturing a metal tube having a metal matrix composite material membrane lined with a metal matrix composite material membrane on its inner surface, and in particular to various combustion tubes and transportation tubes for nuclear waste treatment. The present invention also relates to a method of manufacturing a metal tube equipped with a metal matrix composite material film suitable for use as a metal tube used for chemical plant piping, etc.

0002

2. Description of the Related Art Conventionally, the following methods have been used for lining the inner surface of a metal tube with a metal matrix composite material film.

(1) PVD (Physical Vap)
or Deposition) equipment or CVD (Ch
chemical vapor deposition)
A vapor deposition method in which a metal matrix composite material is heated in a vacuum using a device, etc., and the metal matrix composite material is vapor-deposited on the inner surface of a metal tube to form a lining film.

(2) A thermal spraying method in which a thermal spray material made of a metal matrix composite material is melted using a plasma flame or the like, and this metal matrix composite material is sprayed onto the inner surface of a metal tube using gas jet pressure to form a lining film.

(3) A method of forming a cylinder made of a metal matrix composite material and shrink-fitting the cylinder to a metal pipe, casting or diffusion bonding by brazing.

[0006]

However, the above-mentioned conventional method has the following problems. That is, (1)
This method requires equipment such as a vacuum chamber, an evaporation crucible, and a heating source. Furthermore, the thickness of the lining film that can be formed by this method is limited to a few millimeters, and it takes a long time to form the lining film.

[0007] Method (2) requires equipment such as a plasma generator and a thermal spray gun, and the initial cost is high. Further, the thickness of the lining film that can be formed by this method is limited to about 1 mm at most, and if the film thickness is made thicker than that, problems such as cracking and peeling of the lining film will occur. Furthermore, the structure of the lining film formed by this method is not dense, resulting in poor wear resistance.

In the method (3), there is a step of forming a tube made of a metal matrix composite material, such as a cold isostatic pressing (hereinafter referred to as CIP) step and a sintering step, and a step of forming a tube made of a metal matrix composite material. This requires a process of shrink fitting, casting, or diffusion bonding by brazing, which results in poor workability.

The present invention has been made in view of these problems, and it is possible to obtain a lining film that is thick and has a dense structure and has excellent wear resistance, and has good workability. An object of the present invention is to provide a method for manufacturing a metal tube equipped with a metal matrix composite material membrane.

0010

[Means for Solving the Problems] A method for manufacturing a metal tube equipped with a metal matrix composite material membrane according to the present invention includes arranging an inner tube made of an elastic member inside the metal tube and connecting the metal tube and the inner tube. a step of filling a mixed powder of metal powder and ceramic powder between the tubes, a step of sealing the mixed powder, and a cold isostatic press treatment to form a green compact of the mixed powder on the inner surface of the metal tube. a cylindrical inner wall portion disposed inside the metal tube, and a cylindrical outer wall portion disposed outside the metal tube; the inner wall portion A step of charging the metal tube covered with the powder compact into a container capable of airtightly sealing the space between the container and the outer wall portion, and removing the container with the inside of the container deaerated. It is characterized by comprising a step of sealing, a step of applying hot isostatic pressing, and a step of removing the container.

[0011]

[Operation] The inventors of the present invention have conducted various experimental studies in order to manufacture a metal tube having a metal matrix composite material film that is thick and has a dense structure. As a result, by applying a green compact made of metal powder and ceramic powder to the inner surface of the metal tube in advance and then applying hot isostatic pressing (hereinafter referred to as HIP), the film is thick and has a dense structure. We have discovered that a metal matrix composite film can be easily formed on the inner surface of a metal tube. The present invention was made based on such experimental results.

That is, in the present invention, first, an inner tube made of an elastic member such as a rubber tube is placed inside a metal tube, and a metal powder and a ceramic powder are placed between the metal tube and the inner tube. Fill with mixed powder. Then, for example, rubber plugs or the like are placed at both ends of the metal tube to seal the mixed powder. Next, CIP treatment is performed to adhere a green compact of the mixed powder to the inner surface of the metal tube. Thereafter, after removing the inner cylinder etc. from the metal tube, the metal tube is inserted into a container. The container includes an inner wall disposed inside the metal tube and an outer wall disposed outside the metal tube, and airtightly seals a space between the inner wall and the outer wall. It is now possible to do so. Next, after deaerating the inside of this container, the container is sealed. Next, this container is subjected to HIP treatment. In this HIP process, the green compact is sintered, and as a result, a metal matrix composite material film is formed on the inner surface of the metal tube.

In the method of the present invention, since the metal matrix composite material film is thus formed on the inner surface of the metal tube, a thick metal matrix composite material film can be easily formed. Moreover, since the metal matrix composite material film formed by the method of the present invention has been subjected to HIP treatment, it has a dense structure and high wear resistance.

[0014]

Embodiments Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIGS. 1 to 5 are cross-sectional views showing a method according to an embodiment of the present invention in the order of steps.

First, as shown in FIG. 1, a rubber tube 2 is placed inside a metal tube 1, and a mixed powder 3 of metal powder and ceramic powder is filled between the metal tube 1 and the rubber tube 2. . Then, rubber plugs 4 are placed at both ends of the metal tube 1 to seal the mixed powder 3.

Next, as shown in FIG. 2, a green compact 3a made of mixed powder is applied to the inner surface of the metal tube 1 by CIP treatment. Thereafter, the rubber tube 2 and rubber stopper 4 are removed.

Next, as shown in FIG. 3, this green compact 3a
The metal tube 1 coated with the metal tube 1 is charged into the container 5. The container 5 has an inner wall 5a arranged inside the metal tube 1 and an outer wall 5b arranged outside the metal tube 1, and the space between the inner wall 5a and the outer wall 5b is kept airtight. It is now possible to seal it in. Moreover, this container 5 is
It is connected to a vacuum pump (not shown) via a degassing tube.

Next, as shown in FIG. 4, the inside of the container 5 is sufficiently degassed, the deaeration pipe is sealed, and the vacuum pump and the container 5 are separated, and then the container 5 is subjected to HIP treatment. . In this HIP process, the powder compact 3a is sintered, and a metal matrix composite material film 6 is formed on the inner surface of the metal tube 1.

Next, as shown in FIG. 5, the container 5 is removed. Thereby, a metal tube whose inner surface is lined with the metal matrix composite material film 6 can be obtained.

Next, the results of actually manufacturing a metal tube provided with a metal matrix composite material film using this method will be explained.

First, titanium powder with an average particle size of 15 μm and SiC (silicon carbide) powder with an average particle size of 5 μm were blended in a weight ratio of 9:1 to obtain a mixed powder. Next, S
An inner tube made of a rubber tube was placed inside a metal tube made of 45C steel (JIS G 4051 carbon steel), and the above-mentioned mixed powder was filled between the metal tube and the rubber tube. Then, rubber stoppers were placed at both ends of this metal tube to seal the mixed powder. Thereafter, a pressure treatment was performed using a CIP device at a pressure of 3 tons/cm 2 to coat the entire inner surface of the metal tube with the green compact of the above-mentioned mixed powder.

Next, this metal tube was placed in a steel container. This container includes an inner wall portion placed inside the metal tube and an outer wall portion placed outside the metal tube, and the space between the inner wall portion and the outer wall portion can be hermetically sealed. It looks like this. Additionally, this container is connected to a vacuum pump via a degassing tube.

Next, the inside of this container was sufficiently degassed using a vacuum pump, and then the container was sealed and separated from the vacuum pump. Thereafter, this container was subjected to HIP treatment at a pressure of 1200 atm and a temperature of 1200°C.

Next, the steel container was cut and removed using a lathe. As a result, a metal tube according to the example was obtained, which was lined with a titanium-based composite material film having a film thickness of 5 mm.

On the other hand, a metal tube as a comparative example was manufactured. That is,
First, a mixed powder having the same composition as the above-mentioned mixed powder was packed into a rubber mold. Then, using a CIP device, this rubber mold was subjected to pressure treatment at a pressure of 3 tons/cm 2 to obtain a cylindrical green compact. Next, this green compact is placed in a vacuum furnace for 1
Sintering was performed at a temperature of 300°C to obtain a cylinder made of a titanium-based composite material. Next, this cylinder was shrink-fitted to a metal tube made of S45C steel material, thereby obtaining a metal tube according to a comparative example lined with a titanium-based composite material film having a film thickness of 5 mm.

The following characteristics were investigated for the metal tubes provided with the titanium-based composite material membranes of this Example and Comparative Example.

(2) Specific gravity The specific gravity of the lining film was measured using a micropycnometer. ■Hardness The hardness of the lining film was measured using a Vickers hardness meter. ■Specific wear amount The specific wear amount of the lining membrane was measured using an Okoshi type rapid wear tester.

The results of these measurements are summarized in Table 1 below.

[0030]

[Table 1]

As is clear from Table 1, the metal tubes of the examples have denser lining films, higher hardness, and lower specific wear than the metal tubes of the comparative examples.

[0032] In the above embodiments, the case where the metal matrix composite material is a titanium matrix composite material was explained, but iron matrix composite material, aluminum matrix composite material, copper matrix composite material, copper matrix composite material,
In the case of other metal matrix composite materials such as nickel base composite material and cobalt base composite material, metal matrix composite material films can be formed in the same manner as in the above-mentioned embodiments. Also,
In addition to the above-mentioned S45C steel, metal tubes include SK material (JISG 4401 carbon tool steel) and SKD material (J
Various metal tubes can be used, such as IS G 4404 alloy tool steel), stainless steel, and SCM material (JIS G 4105 chromium molybdenum steel).

Furthermore, the ceramics that can be used in the present invention are not limited to the above-mentioned SiC, but include Cr.
2 O3, TiO2, ZrO2, MgO and Y2
Oxide ceramics such as O3, Si3 N4,
Nitride ceramics such as TiN, BN and AlN, T
Various materials can be used, such as carbide ceramics such as iC, B4C, CrC2, and WC, boride ceramics such as ZrB2 and TiB2, and sialon. Moreover, two or more types of these ceramics can be mixed and used.

[0034]

Effects of the Invention As explained above, according to the method of the present invention, hot isostatic pressing is performed after a green compact made of metal powder and ceramic powder is applied to the inner surface of a metal tube, so that the film thickness can be reduced. It is possible to easily manufacture a metal tube whose inner surface is provided with a metal matrix composite material film that is thick, has a dense structure, and has excellent wear resistance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one step of an embodiment method of the present invention.

FIG. 2 is a sectional view showing one step of the process.

FIG. 3 is a cross-sectional view showing one step of the process.

FIG. 4 is a sectional view showing one step of the process.

FIG. 5 is a cross-sectional view showing one step of the process.

[Explanation of symbols]

1; Metal tube 2; Rubber tube 3; Mixed powder 3a; Green compact 4; Rubber stopper 5; Container 6; Metal matrix composite material membrane

Claims (1)

[Claims] 1. A step of arranging an inner tube made of an elastic member inside a metal tube and filling a space between the metal tube and the inner tube with a mixed powder of a metal powder and a ceramic powder; a step of sealing, a step of applying a cold isostatic press treatment to apply the green compact of the mixed powder to the inner surface of the metal tube, a step of removing the inner tube, and a step of disposing it inside the metal tube. The above metal tube is placed in a container that includes a cylindrical inner wall and a cylindrical outer wall disposed outside the metal tube, and is capable of airtightly sealing a space between the inner wall and the outer wall. A step of charging a metal tube covered with a powder compact, a step of sealing the container with the inside of the container deaerated, a step of applying hot isostatic pressing treatment, and a step of removing the container. A method for producing a metal tube equipped with a metal matrix composite material film, characterized in that the method comprises: