JPH07256468A - Solid phase diffusion joining method - Google Patents

Abstract

PURPOSE:To enable solid-phase diffusion joining of intricate joint surfaces by embedding joining members into the ceramic particles packed into a capsule and applying a hydrostatic pressure thereon from outside in a state of pressing the joining members to each other. CONSTITUTION:The ceramic particles 12 are packed into an outside cylinder 11 made of steel to be used as the capsule. The joining members 13, 14 pressed to each other are embedded into these ceramic particles 12. The outside cylinder 11 made of steel is hermetically sealed and the hydrostatic pressure is applied isotropically on the outside cylinder 11 made of steel under heating. The final pressure medium directly acting on the joint parts 3, 4 are formed of the ceramic particles 12 and, therefore, the hydrostatic pressure acts on the joint surfaces and the solid phase diffusion joining is made possible if the ceramic particles 12 are so packed as not to intrude into the spacing between the joint surfaces. The pressurizing force is preferably >=1MPa and the upper limit thereof is sufficient with 1000MPa. The heating time is preferably >=0.5Ks and the upper limit thereof is sufficient with 20Ks.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a metal material, a composite material,
The present invention relates to a solid-phase diffusion bonding method in which a joining member made of a ceramic material or the like is used, and pressure and heat are applied to the abutting surfaces of the joining member to join the members in a solid-phase state. The present invention relates to a solid-phase diffusion bonding method that is carried out.

[0002]

2. Description of the Related Art There is a method in which the surfaces of two or more members to be bonded to each other are accurately finished to be smooth, and the surfaces are bonded in a solid state while applying heat and pressure. This joining method is generally called diffusion joining, and its procedure is shown in FIG. That is, when the members A and B to be joined are made of a metallic material, the crystal grain size thereof is fine, 1 μm or less, and the joining surface is finished to have a ten-point average roughness of 0.1 to 0.2 μm or less and is clean. Is required. Then, the joining members A and B are sandwiched between the pressurizing jigs 1 and 2 and heated to a predetermined temperature under a predetermined pressure P in a vacuum in the vacuum container 3. Bonding takes about 2 to 18 ks. In addition, 4 is a heater for heating and 5 is an oil seal for sealing. On the other hand, as shown in FIG. 7, a foil-shaped insert material (metal) C is sandwiched between the joining members A and B, and pressure and heat are applied to cause the joining members A and B and the insert material C to react with each other. There is a joining method that joins together. In this method, the crystal grain size of the joining member may be coarse, the finishing accuracy of the joining surface is 1 μm or less, and the distance between the joining members A and B is 5 to 10 μm.
The insert metal C having a thickness of about 0 μm is sandwiched and bonded by applying pressure and heat for 3.6 Ks or more in a vacuum or an inert gas for 3.6 Ks or more.

[0003]

According to the method shown in FIG. 6, the deformation of the members can be bonded as much as possible and the strength of the bonded portion is excellent, but the bonding condition is as described above. The diameter is required to be 1 μm or less, the finishing accuracy of the joining surface is high, the atmosphere is vacuum, and the joining time is 7.2 Ks or more. On the other hand, the joining method using the insert material is the same as the method shown in FIG. 6, but the pressing means is basically performed by pressing, and a large-sized press machine is required. Moreover, it is possible to join only on the surface perpendicular to the applied pressure. Therefore,
The joining members are limited to those having a simple shape, and joining with a complicated shape surface is not possible. Further, it is naturally impossible to simultaneously compound the surface portion of the joining member with the compound material. The present invention has been made in view of the above circumstances, and an object thereof is to provide a solid phase diffusion bonding method that solves the above problems.

[0004]

According to the present invention, in the case of joining a joining member in a solid phase state, the present invention is embedded and sealed in ceramic particles filled in a capsule with the joining member abutting. Then, while keeping the whole at a predetermined temperature,
The above problems were solved by a solid phase diffusion bonding method in which hydrostatic pressure is applied from the outside of the capsule to bond in a solid phase state. According to the present invention, solid-phase diffusion welding can be performed on a complicated joining surface of a joining member, and at the same time, the joining member surface can be composited.

The present invention will be described in detail below with reference to the drawings. As the ceramics used in the present invention, for example, ceramic particles of SiC, Si ₃ N ₄ , SiO ₂ , Al ₂ O ₃ or the like can be used. These ceramic particles may be a mixture of different kinds of ceramic particles. The particle size of the ceramic particles is preferably 100 μm or less so that pressure transmission can be carried out smoothly, and the lower limit of 0.1 μm is sufficient. For processing, as a capsule,
For example, as shown in FIG. 1, a steel outer cylinder 11 is used, the ceramic particles 12 are filled in the outer cylinder 11, and the joining members 13 and 14 in contact with each other are embedded between the ceramic particles 12. Next, after sealing the steel outer cylinder 11, isostatic pressure is applied to the steel outer cylinder 11 from the isotropic direction while heating. Reference numeral 15 indicates the heating heater. The applied pressure is 0.1MPa in order to join the members smoothly and uniformly.
The above is good, and an upper limit of 1000 MPa is sufficient. In addition, the heating time is preferably 0.5 ks or more, and the upper limit is 20 ks, which is sufficient for sufficient bonding. The heating temperature is appropriately selected according to the type and material of the joining members. As a structure of a joining member for joining, specifically, for example, as shown in FIGS. 2 (a) and 2 (b), a cylindrical cylinder 21 and a top portion of the cylinder 21 are made of, for example, a high-temperature wear-resistant material. There is an embodiment mode in which the disc 22 to be joined is joined and a metal foil 23 for insert sandwiched between the disc 22 and the cylinder 21 is embedded in the ceramic particles.

In the method according to the present invention, the final pressure medium acting directly on the joining member is ceramic particles. Therefore, if the ceramic particles are prevented from entering the joining surface of the joining member, hydrostatic pressure is applied to the joining surface. In addition, solid phase diffusion bonding becomes possible. Now, if gas is used as the final pressure medium, isotropic hydrostatic pressure is applied to the joint surface, so that joining is not possible. That is, in the state shown in FIG. 1A of the present invention, the pressure P is isotropic (not completely isotropic), and therefore, as indicated by an arrow M in the drawing, with respect to the joint surfaces of the joint members 13 and 14. By acting through the ceramic particles, it is possible to join even if the joint surface has a complicated shape or faces either direction. Further, when there are internal defects (such as cavities and voids) in the member, they are crushed. If necessary, the ceramic particles that are the pressure medium are allowed to enter the surface of the joining member,
The part can be compounded. Therefore, the press machine required for solid phase diffusion bonding is also unnecessary. On the other hand, when gas is used as the final pressure medium, the pressure for pressing the joint surfaces of the joint members 13 and 14 as shown by the arrow N in FIG. In addition, defects connected to the surface of the member will not collapse.

[0007]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited to these examples. Example 1 SiC particles having an average particle diameter of 5 μm were filled in a JIS SPCC outer cylinder of φ40 × 45 mm. As a joining member, a JIS AC8A alloy with Si having an average particle size of 5 μm was used.
Φ25 made of a composite material with C particles added at 5 mass%
× h20mm cylinder and φ20 × h2.5mm JIS S
Prepare a disk of KD11, and place φ20 × h between these members.
A Cu disk foil of 0.02 mm is sandwiched, combined as shown in FIG. 2 and embedded in SiC particles, and the inside of the outer cylinder is set to 0.1 P.
After reducing the pressure to about a, it was sealed by welding. After that, while the whole is heated to 823K by a hot isostatic pressure (HIP) device, a hydrostatic pressure of about 100MPa in Ar atmosphere is about 3.6k.
added for s. As a result of the above processing, as shown in FIG.
The member made of the 8A alloy composite material and the member of SKD11 could be solid phase diffusion bonded, and further, SiC particles could penetrate into the surface of the AC8A alloy composite material to form a composite. This member was processed into a valve lifter as shown in FIG. 2C in the next step. This valve lifter is lightweight because the main body matrix is made of aluminum alloy, and the top part that requires wear resistance due to sliding with the cam is supplemented with a high wear resistant material, and it can be a good part that can withstand sufficient use. It was Note that the abrasion resistance required for the side surface was sufficient with a composite of SiC particles.

Example 2 In an outer cylinder made of JIS SPCC of φ100 × h100 mm,
SiC particles having an average particle diameter of 5 μm were filled. The AC4C cylinder head 25 shown in FIG.
In order to improve the high temperature strength of the combustion chamber, a disk 26 of a composite material in which 20 mass% of SiC particles having a diameter of 10 μm is added to the AC8A alloy is brought into contact, and these are embedded in the SiC particles, and the inside of the outer cylinder is After reducing the pressure to about 0.1 Pa, it was sealed by welding. After that, the entire HIP device
While heating to K, a hydrostatic pressure of about 100 MPa was applied for about 3.6 ks in an Ar atmosphere. As a result, as shown in FIG. 5B, these could be solid-phase diffusion bonded, and the SiC particles could be infiltrated into the surface of the AC4C alloy to form a complex. The enlarged structure of the joint portion S is shown in FIG. The finished cylinder head has a composite material applied to the combustion chamber, which improves the high-temperature strength of the combustion chamber. Also, since the matrix of the composite material is an aluminum alloy, it has good heat conduction (cooling) with the main body. It was a good component that could withstand high temperature combustion, high speed rotation, and long-term operation.

[0009]

As described above, according to the present invention, in solid phase diffusion bonding, a large-sized press machine conventionally required is not necessary, and even a bonding surface having a complicated shape can be bonded. became. That is, since hydrostatic pressure is applied to the joint surface, the joint surface can be joined regardless of which direction it is facing. Also, since the joining member receives the HIP effect,
Even if there are cavities or gaps inside, it will be crushed, so internal defects can be eliminated. In addition, the ceramic particles used as the pressure medium can be simultaneously introduced into the surface of the joining member, and it has become possible to combine the parts.

[Brief description of drawings]

FIG. 1 is an explanatory view of a method related to the present invention, in which FIG.
Is a diagram for explaining the method of the present invention, and FIG. 7B is a diagram for explaining another method compared with this.

FIG. 2 is an embodiment of the present invention, in which (a), (b),
(C) is a figure explaining the point.

FIG. 3 is a photograph, instead of a drawing, showing an enlarged metallographic structure of a joined cross section of members joined by the method according to the present invention.

FIG. 4 is a photograph, which replaces a drawing, showing a metal structure in which a joint cross section of another example is enlarged.

5A and 5B are views for explaining a joining procedure of another embodiment of the present invention, in which FIG. 5A is a perspective view of a cylinder head and FIG.
FIG. 4 is an explanatory diagram of a cross section taken along line XX of FIG.

FIG. 6 is a diagram illustrating a procedure of a solid phase diffusion bonding method.

FIG. 7 is a diagram illustrating a procedure of a solid phase diffusion bonding method using an insert material.

[Explanation of symbols]

 11 Steel Outer Tube 12 Ceramic Particles 13 Joining Member 14 Joining Member 21 Cylinder 22 Disc 23 Metal Foil

Claims (2)

[Claims] 1. When the joining member is joined in a solid state, the joining member is abutted and embedded in the ceramic particles filled in the capsule and sealed, and the whole is kept at a predetermined temperature from outside the capsule. A solid-phase diffusion bonding method characterized in that hydrostatic pressure is applied to bond in a solid phase. 2. The solid phase diffusion bonding method according to claim 1, wherein an insert material is interposed between the bonding members.