JPS63206408A - Production of composite member by diffusion joining - Google Patents

Abstract

PURPOSE:To simply form a coating layer on the inner surface of the partially expanded hollow of a base material by putting powder or granules in the space between the base material and a cylindrical case inserted in the hollow, expanding the case and subjecting the powder or granules to diffusion joining. CONSTITUTION:A cylindrical case 2 of a metal is inserted in the partially expanded hollow of a base material 1. Powder or granules 3 are put in the space between the case 2 and the base material 1 and the outsides of the boundary between the base material 1 and the case 2 are sealed with end plates 4. While they are rotated on an axis, pressure is locally applied to the inside of the case 2 to expand the case 2 to a prescribed shape. The powder or granules are then adhered to the inner surface of the hollow of the base material 1 by diffusion joining such as hot isostatic pressing treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is applicable to members such as valve members having a hollow part in which the diameter of the hollow part in the middle part is larger than the diameter of the openings at both ends. , a surface layer having various properties such as heat resistance and wear resistance is applied to the inner wall of the hollow part of a member whose diameter is not uniform depending on the part, such as a member having one or more depressions on the inner wall of the hollow part. The present invention relates to a method of coating.

<Prior Art> This type of member is widely used in industry, but it has many difficulties because the inner wall surface of the hollow part must be coated with various materials. In other words, with the plating method, materials are limited and it is difficult to make the thickness uniform for objects with complicated shapes.The thermal spraying method cannot be used in practice because the work is done internally, and the cladding method However, it is difficult to adopt this method because the diameter of the hollow part varies depending on the part.

Therefore, although the number of steps increases, it is common to divide the target member into two or more parts and use the various coating methods described above.

In addition, as a special method, the coating material is used in the form of powder and granules and sintered on the desired surface of the inner wall of the hollow part of the target member. A possible method is to mold the material and sinter it under hot isostatic pressure for each case. However, if the diameter of the hollow part of the target member is not uniform depending on the part, for example,
In the case of the member (,) shown in the figure, the case (b)
) could not be inserted into the hollow part if it had the same shape as the hollow part, so we had no choice but to use a cylindrical case (b) with a diameter smaller than the diameter of the opening end of the hollow part, and combine the parts (a) and the case (
b) There is no choice but to adopt a method of sintering with the granular coating material (c) packed in between. However, with this method, the target product is coated with a uniform thickness H on the inner wall of the hollow part as shown in Figure 14.
(e'), it requires an unnecessarily large amount of powder coating material (e), which wastes expensive coating material, and it takes a long time to remove the excess portion. Since it is generally a difficult-to-cut material, it has the disadvantage of being difficult to remove.

<Problems to be Solved by the Invention> The present invention solves the above-mentioned drawbacks of the conventional method, does not require the target member to be divided into pieces, does not use more than the necessary amount of coating material, and can easily be used as a base material. The purpose of the present invention is to provide a method that allows the formation of a coating layer of a wearable thickness on the inner surface of a hollow part of a material.

<Means for solving the problems> The above object of the present invention can be achieved by the following method. That is, a metal cylindrical case is inserted into the hollow part of a base material that is made of a block having a hollow part with at least one end opened outward, and the diameter of the hollow part is not the same depending on the part. , furthermore, a powder material is accommodated between the base material and the case, the outer surface of the boundary between the base material and the case is sealed, and then the case is rotated about the central axis in the longitudinal direction of the case. After expanding the diameter of the case into a predetermined shape by applying local pressure from the inner circumferential surface using a pressure jig such as a roller, the powder and granules are bonded to the base material by hot isostatic pressure treatment, etc. This is a method for manufacturing a composite member by diffusion bonding, which is characterized in that the composite member is attached to the inner surface of a hollow portion of the composite member.

The powder and granules used in the present invention are metals (including alloys), ceramics, or a combination thereof, and other metals (including metal alloys) for promoting sintering are coated on the surface of the powder or granules to facilitate subsequent sintering. (including alloys) etc. may also be used. In this case, as detailed later,
If the amount of powder and granule to be filled is set to an amount that occupies a smaller volume than the space in which it is stored, not only will it be easier to fill the powder and granule, but the green compact that will be molded in subsequent operations will It is more effective because it is more homogeneous in terms of density and thickness.

However, when filling powder or granules into a certain space, especially a narrow space, even if a special method such as special pushing or applying impact vibration etc. and filling very small quantities is adopted, the powder or granules are Depending on the shape, the volume occupied by the powder or granule is inevitably smaller than the above space due to the voids or "shelf hanging parts" that occur between the powder or granules, and the unavoidable void that occurs at the top end during filling. Considering these facts, the amount of powder and granules will occupy a smaller volume than the space in which they are stored, although there are differences in degree in each of the above cases.

After filling the powder or granular material determined by the amount of the coating layer in this way, the space between the opening of the hollow part and the case is sealed either directly or by applying an annular end plate, etc., but if the inside is kept in a vacuum state. This is preferable because the internal powder and granules are not contaminated by oxidation or the like during subsequent operations or when left for a certain period of time.

Note that the method of the present invention includes the case where the base material has a plurality of hollow portions, but it also includes the case where the base material has a plurality of hollow portions.

The rotation after sealing is performed around the long axis of the case inserted into each hollow part. Therefore, when targeting a base material with multiple hollow parts, the case insertion, powder filling, and Although sealing may be performed at the same time, local pressure application during subsequent rotation should be performed in each case.

Note that when the case is rotated after being filled with powder or granular material in the method of the present invention, the case is set in a horizontal position, an H-necked shape, or an oblique-necked shape, taking into consideration the shape of the case. From the point of view of evenly distributing powder and granules, in general, if the case is long in the vertical direction, horizontal placement is preferable in order to reduce the effect of gravity, and if the case is short and flat, In some cases, it is preferable to place the powder vertically so that gravity does not affect it so much and it is easy to rotate. If the branch pipe is to be sufficiently filled with powder and granules, it may be desirable to rotate the case vertically and utilize gravity in addition to centrifugal force. Also, by rotating the case vertically and adjusting the centrifugal force and gravity at that time, it is possible to gradually increase the amount (thickness) of the powder from the top to the bottom of the case. .

Therefore, it is possible to rotate horizontally or vertically1. It is possible to select an appropriate direction in consideration of the above-mentioned matters, and depending on the case, there may be an oblique direction between the two.

In this case, if part or all of the powder or granule is shaped into long fibers or cut wires in one direction to gradually narrow the space while rotating, the powder or granule may be placed in the case. They can be aligned along the longitudinal direction, and the finally formed coating layer can have directional strength.

Further, the above-mentioned local pressurization may be performed not only in a cold state but also in a hot state by heating each local part to be pressurized or by heating the entire area.

<Effect> The method of the present invention will be described in detail below with reference to the drawings.

The present invention relates to a base material (1) in which the central part of the hollow part is larger than the diameter of the opening, as shown in FIG. Base material that differs depending on location (1
) is a method of forming a coating layer with desired characteristics on the inner wall surface of a hollow part. The outer shape of the base material (1) may be circular in cross-section, over-shaped in cross-section, or in other complicated shapes. A cylindrical case (2) whose outer diameter is still smaller than the diameter of the smallest diameter part of the hollow part is inserted into the base material (1) as shown in FIGS. 1 and 2, As shown in Fig. 3, a powder (3) is accommodated between the base material (1) and the case (2),
The end plate (4) is brought into contact with the opening to seal it. In this case, the amount of the powder (3) is determined by the thickness of the coating layer to be obtained, but the capacity of the powder (3) in the space between the base material (1) and the case (2) is As mentioned above.

In addition, in FIGS. 1 to 3, the case where the hollow part of the base material (1) is open at both ends is shown, but one end of this hollow part may be closed. ) is preferably open at both ends in view of ease of manipulation and deformation in order to expand the diameter later. Then, while rotating the case (2) about its longitudinal axis using an appropriate rotation device (not shown), press a pressure jig (5) such as a roller from the inside of the case (2). , the diameter of the case (2) is expanded by moving it one by one.This powder powder (3)
) is subject to centrifugal force due to rotation, so if the volume of the powder (3) is smaller than the gap between the two cases, the powder and granules are apparently packed upwards. Even in the case of rotation, the above-mentioned voids and hanging parts between the powder and granules are eliminated, making it possible to move. If the case is made to have a uniform density in every part of the case, and the diameter of the case is expanded by repeatedly applying local pressure in this state, the amount of deformation of the case will differ depending on the part, and the amount of powder and granules present will be reduced. Although the thickness (thickness) is constant or varies, compacted powder particles with uniform density can be obtained at any location. In detail, if the base material (1) is deformed along the shape of the hollow part, a compacted powder granule with a uniform thickness can be obtained as shown in FIG.
The deformation of the central part of the case is more pronounced than the former (in the case of Fig. 5).
If it is kept modest, the thickness of the compacted powder can be made to exist only in that part. Furthermore, as shown in Fig. 7, the thickness of the compacted powder granules can be increased sequentially from both openings of the hollow part toward the center. If a product with recesses is used, it is possible to make the powder granules exist only in the grooves or recesses, or to make the powder granules exist in the grooves or recesses together with other inner wall parts. In addition, without forming grooves or recesses on the base material (1),
Even if the inner wall surface of the hollow part is smooth, it is possible to form protrusions in a desired shape by applying pressure from the case (2) as shown in FIG.

The base material (1) used in the method of the present invention is as described above (at least one end of the hollow part may be open and the other end may be closed, for example, as shown in FIG. 9). It is also possible to adopt a combination of base material (1) with a similar shape and case (2), and in this case, a coating layer may be applied to the entire inner circumferential wall of the enlarged diameter cavity inside base material (1). There is also a base material (
As mentioned earlier, in 1), as long as at least one end has a hollow part that is open to the outside, there are no restrictions on the external shape or the number of hollow parts. When specifically using a valve member as the base material (1), as shown in FIG. In addition, when a hole (branch pipe) for inserting another member is opened in part A of Fig. 10, and it is necessary to make powder granules exist on the inner wall of the hole, , base material (1)
The depth of the recess provided in the inner wall of the hollow part is made so that the base material (1) is deep enough that the powder to be filled will not leak out, as shown in Figure 11.
Either leave that part or make the recess pass through to the outer surface of the base material (1) as shown in Figure 12, seal it with a separate lid (4') to prevent powder leakage, and then open the hole later. In some cases, a method is adopted in which powder compacts are formed even in areas where opening is required.

In this case, of course, a core may be placed in advance at the location where the hole will be drilled later.

In this way, after compacting the powder to the inner wall of the hollow part of the base material in an appropriate shape and with a uniform packing density, the powder and granules can be bonded by various diffusion bonding methods such as hot isostatic pressing in that state. The particles are diffused and bonded on the spot and firmly bonded to the base material, and the case is removed by cutting or the like to obtain the desired product.

<Example> Examples of the present invention will be described below.

This example concerns a method of coating the inner wall of the hollow part of a valve member material having the shape shown in FIG. 1 with a corrosion-resistant and wear-resistant material. That is, a base material made of 545C material having a shape as shown in FIG.
A mild steel case with an outer diameter smaller by 10 mm is inserted, and austenitic stainless steel (SUS316) powder is filled with a volume of approximately 80% of the space between the base material and the case, and a mild steel ring is inserted between both openings. After applying and sealing the end plates, the interior is vacuumed, the entire case is placed horizontally, and while rotating, a small roller is applied from the inner wall side of the case to apply local pressure to the entire case, and the case is placed on its base material. The diameter was expanded until it had a shape that followed the hollow part. Next, it is charged into a hot isostatic pressurizing device, and 115
After being maintained at 0° C. and 1000 kg/crj for 2 hours, it was taken out, and the case was cut and removed to obtain a base material coated with a stainless steel layer.

<Effects of the Invention> As described above, according to the method of the present invention, considering the shape of the base material and the part where the coating layer is to be applied, the case used or the base material itself must be of a split assembly type. It is possible to easily and accurately manufacture and repair parts such as valve members having an enlarged diameter cavity inside, for which it is difficult to obtain a sintered coating layer from granules.

In addition, in the method of the present invention, the thickness of the coating layer of the final product can be adjusted appropriately by adjusting the size of the case used and the amount of powder and granules. If the inside is evacuated beforehand, the powder inside will not be contaminated during subsequent processing even if left in that state, and the case, which has become work-hardened during local pressure deformation, will be softened. It is also possible to perform heat treatment to transform the material into a more complex shape.

In addition, in the method of the present invention, after filling the powder and granules, the powder and granules are compacted by local pressure, so even if the apparent density of the powder and granules varies depending on their shape, the apparent Because it is possible to determine the exact amount by weight regardless of the density, it is easy and accurate to determine the amount of powder or granules. In this case, if the case is damaged, there is a fear that the high-pressure liquid will be forced into the case and contaminate all the powder and granules, but with the method of the present invention, such a situation is not conceivable. Even if the case is damaged, it can be repaired or replaced on the spot.

[Brief explanation of the drawing]

Fig. 1 is a schematic illustration of the product to be manufactured by the method of the present invention, Figs. 2 to 4 are illustrations of each step of the method of the present invention, and Figs. FIGS. 10 to 12 are explanatory diagrams showing the shapes of various compacted powder granules produced by the method of the present invention, respectively, and FIGS. An explanatory diagram of a conventional method. In the figure: (1): Base material (2) Two cases (3) Powder (4) End plate Patent applicant Kuroki Kogyo Co., Ltd. Agent Noriharu Ariyoshi Figure 11 Figure 12 Figure 13 Procedural amendment (self-restraint September 17, 1988 Patent Application No. 38714 3, Representative of the person making the amendment: Kuromizu Gai 4, Attorney's specification (1), scope of patent claims in the specification below) [1. When at least one end of the base material is opened outward, the base material is made of a block having a hollow part, and the diameter of the hollow part is not the same depending on the part. , a metal cylindrical case is inserted, and the outer surface of the boundary between the base material and the case is sealed, and then, while the case is rotated about its longitudinal central axis, a roller is inserted from the inner peripheral surface of the case. After enlarging the diameter of the case to a predetermined shape by applying local pressure using a pressure jig such as the above, the powder and granules are attached to the inner surface of the hollow part of the base material by diffusion bonding such as hot isostatic pressure treatment. A method for manufacturing a composite member by diffusion bonding, characterized by A method for manufacturing a composite member by diffusion bonding according to claim 1, characterized in that the case is transformed into a desired shape by changing the case according to claim 1 or 2. A method of manufacturing a composite member by diffusion bonding. 4. Claim 1, characterized in that the base material has a shape having more than one circumferential or spiral groove on the inner circumferential wall of the hollow portion thereof. A method for manufacturing a composite member by diffusion bonding according to any one of Items 1 to 3. 5. Claims characterized in that the base material has a shape having one or more recesses in the inner circumferential wall of the hollow portion thereof. Section 1~
A method for manufacturing a composite member by diffusion bonding according to any one of Item 4. 6. Composite by diffusion bonding according to any one of claims 1 to 5, wherein at least a part of the powder or granular material has a shape elongated in one direction, such as a fibrous shape or a rod shape. Method of manufacturing parts. (2) In page 5, line 20 of the specification, ``ceramic or'' is amended to ``ceramic that also includes so-called glass. carbon or''.

Claims (1)

[Scope of Claims] 1. In the hollow part of the base material, which consists of a block having a hollow part with at least one end opening outward, and the diameter of the hollow part is not the same depending on the part, A metal cylindrical case is inserted, and the outer surface of the boundary between the base material and the case is sealed, and then pressure is applied from the inner peripheral surface of the case by a roller or the like while the case is rotated about the central axis in the longitudinal direction. The case is characterized by expanding the diameter of the case into a predetermined shape by applying local pressure using a jig, and then attaching the powder to the inner surface of the hollow part of the base material by diffusion bonding such as hot isostatic pressure treatment. A method for manufacturing composite members using diffusion bonding. 2. Diffusion bonding according to claim 1, characterized in that the amount of granular material accommodated is an amount that has an occupied volume smaller than the volume of the internal space between the base material and the case. Method for manufacturing composite parts. 3. A composite member by diffusion bonding according to claim 1 or 2, characterized in that the amount of local pressurization applied to the case is changed depending on the part, thereby deforming the case into a desired shape. manufacturing method. 4. According to any one of claims 1 to 3, the base material has a shape having one or more circumferential or spiral grooves on the inner circumferential wall of the hollow part. A method for manufacturing composite members by diffusion bonding. 5. Claims 1 to 5, characterized in that the base material has a shape having one or more recesses on the inner circumferential wall of the hollow portion thereof.
A method for manufacturing a composite member by diffusion bonding according to any one of Item 4. 6. Composite by diffusion bonding according to any one of claims 1 to 5, wherein at least a part of the powder or granular material has a shape elongated in one direction, such as a fibrous shape or a rod shape. Method of manufacturing parts.