JPH0364232B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a method of applying a coating to a product.

[Technical background of the invention and its problems]

The present invention has particular utility in coating non-parallel shaped products, pore surfaces, reaction vessels, etc.

Known methods for applying coatings, particularly metallic and ceramic coatings, use various forms of energy, such as plasma or laser spraying. In these methods, the particles that are being sprayed onto the product are melted and deposited onto the product by vapor deposition, packs, or electrodeposition.

However, these methods waste a lot of material, and neither of these methods can guarantee a homogeneous final product. Furthermore, it is almost impossible to maintain a constant coating thickness over the intended surface. Furthermore, these methods cannot be used if the product is made of a reactive material such as titanium.

In addition, a formed covering sheet is placed on the product,
A method is also known in which this material is uniformly compressed at high temperature and crimped onto a product. (See GB-A-2063747). but,
In this method, it is difficult to make the sheet into a shape that fits the product unless the product has a very simple shape. Other methods of directly applying coatings using hot homogeneous compression are described in GB-A-2024256 and GB-
A-2066113, which also has similar drawbacks.

[Purpose of the invention]

The present invention provides a method for applying a coating to the surface of a rigid component to create a composite product having a predetermined shape.

[Summary of the invention]

The method according to the invention consists of the following operations. (a) producing a holder having a partially contoured surface; and (b) applying a coating on said surface of said holder, the combination of said holder and coating being substantially (c) the complementary surface of the part and the surface of the covering are in contact with each other; (d) The parts and the holder thus combined are compressed uniformly at high temperature with sufficient heat and pressure to form a mutually complementary shape in which the above parts and the coating are in contact with each other. It is characterized by the ability to combine surfaces to create composite products.

At least two coatings can be applied to the carrier in the opposite order to the desired order on the product.

The method of the present invention involves applying a coating to a holder in the form of spaced apart sections, pressing the holder at high temperature uniformly onto the product within said spacing, and then applying the coating to the holder over the coating. Including removing.

A filler (anti-bonding agent) can be provided between the carrier and the coating.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In Figures 1 to 1c, the product 10 is an example.
is a turbine blade to which a coating is applied.

The coating is usually metallic and may consist of, for example, any of the following: That is, it can be made of hardened alloys, heat insulating materials, materials with desired electrical properties, materials with resistance to chemical environments, and the like.

The holder 12 can be made of steel, iron or other inexpensive materials and has a surface 13 whose shape corresponds to the shape of the surface of the product 10 to be coated.

As shown in FIG. 1a, the surface 1 of the holder 12
3 is provided with the desired coating 14, which can be applied by plasma spraying, pack deposition, electrolytic deposition, or by first applying a tacky adhesive to the surface 13 and then applying the coating in the form of a dry powder onto the tacky surface. This may be done by any suitable known method such as sprinkling with water. This last method is described in detail in British Patent No. 1334683.

The holder 12 has a coating 14 as shown in FIG. 1b.
is placed against the product 10 with . The item assembled in this way is a metal bag (not shown)
A vacuum is then applied to the bag, after which the bag is collapsed onto the assembly and the assembly is clamped together. The bag is then placed in an oven (not shown), which is then pressurized and heated, thereby effecting hot homogeneous compression of the assembly, resulting in a homogeneous structure of the assembly. be made into

After completion of such operations, the bag is attached to the holder 1
2 from around the assembly by suitable means. A product 10 is then left with a homogeneous coating 14, as shown in FIG. 1c.

If complete coating of the product 10 is required, two holders 12 are made and each of these is coated. These two holders 12 are then placed against each side of the product 10 and their ends are welded to form a bag. A small opening is left to allow a vacuum to be created within the bag, and then a hot isostatic compression operation is performed as described above.

On the other hand, the welding operation can be carried out in vacuum, for example using an electron beam method, in which case a separate vacuum operation is not required.

In FIG. 2, the product 16 has holes 18;
It is desired to apply a coating onto the surface 20 of this hole 18. A retaining mandrel 22 (FIG. 2a) of a suitable diameter is made and coated with the desired coating 24 by a suitable method.
will be applied. The thickness of the coating 24 is such that there is a compression fit between the coated mandrel 22 and the hole 18 (FIG. 2b). Then,
The thus assembled product is placed in a metal bag (not shown), the bag is evacuated, and the bag is placed in a furnace. The entire assembly is then hot homogeneously compressed. The bag, like the mandrel 22, is then removed by machining or other suitable methods, leaving the product 16 with the coated aperture surface 20 (FIG. 2c).

In FIG. 3, the holder 28 is a single plate, and the removal of the holder after hot uniform compression is performed by
8 and the coating 30 by inserting a filler 26, for example powdered ytria (yttrium oxide). As is well known, the filler material 26
prevents diffusion bonding between retainer 28 and coating 30 and provides a relatively weak connection between the two.

In FIG. 4, it is necessary to apply a coating to the product 40 in the form of alternating strips 36 and 38 of different materials.

This allows the holder to be made of material 3, which is one of the desired materials.
This can be achieved by making it from 6. This holder is made in the form of a plate, as shown in FIG. 4a. A strip of other material 38 is placed on the holder 37 and such an assembly is then placed against the product 40 with the strip 38 in between. All operations for hot homogeneous compaction are carried out as previously described, after which the portion of the retainer 36 that lies on the strip 38 of FIG. 4b is shaved off,
This leaves a smooth surface 42 shown in FIG.

In FIG. 5, the outer side of the wall 110 of the combustion chamber of a gas turbine engine (not shown) is the sheet body 11.
It represents what is covered by a skin in the form of 2. The wall 110 is shown in a flat or barrel shape before being bent.

The sheet body 112 is made on the holding plate 114 after depositing particles of heat-resistant material on the holding plate 114. Deposition of the particles may be performed by plasma spraying the retaining plate 114 with the particles. However, the properties of the material of the sheet body 112 and the retaining plate 1
If the properties of the 14 materials are suitable, placing one on top of the other can be done by known methods, for example electrochemically or by rolling.

After attaching the sheet body 112 to the holding plate 114,
Grooves 116 are created in the exposed surface of sheet 112 by conventional cutting or etching, and these grooves 116 are then filled with a material 118 that can be reached (removed), such as ceramic, steel, or iron.

Next, the composite body of the sheet body 112 and the retaining plate 114 is placed on the wall 110 in such a manner that the exposed surface of the sheet body 112 is in contact with the surface of the combustion chamber wall 110, and is further assembled in this manner. The entire product is sealed in a metal bag (not shown), and after the bag is evacuated, it is placed in a furnace (not shown). Then, the inside of the furnace is evacuated, filled with inert gas, and heated. In this case, the temperature and pressure in the oven are increased sufficiently to effect hot homogeneous compaction, bonding wall 110 and sheet body 112 into a homogeneous product.

Also, in FIG. 6, after the product has been cooled, the holding plate 114 is removed by appropriate means. For example, if a filler (bonding inhibitor) is applied between the holding plate 114 and the sheet body 112 before the high-temperature homogeneous compression operation, homogeneous bonding between the two is prevented. A hole 120 is made at the joint between the holding plate 114 and the sheet body 112, and a gas supply pipe 122 is inserted into the hole 120. A gas such as argon is then pumped through the tube 122 and into the bond line. With this, the sheet body 112 and the holding plate 1
14 are separated.

Additionally, the filler material 118 is removed and the wall 110 is bent into a butt weld. This creates a cylindrical shape with clean passages. It is thus possible to drill radial holes in the passages, which makes it possible to provide divergent cooling during operation of the combustion chamber in a gas turbine engine.

Now, in Fig. 7, turbine blade 1
26 has a wing section 128 encased in a skin 130, which covers the wing section 12 in the manner described above in FIGS. 5 and 6.
8.

Prior to attachment to wing 128, grooves 132 are created in skin 130 and these grooves are filled with a removable material (not shown) as described above. These removable materials are removed after installation of the skin 131, leaving the wings 128 covered by the skin 130 with no discontinuities in the surface and leaving the wings 128 covered by the skin 130.
The airfoils 128 and the airfoils 128 form a clean passageway for channeling cooling fluid during operation of the blades 126 in a gas turbine engine.

In both of the above two examples, the skin can be made from a sheet of material having the same composition as the core material, but which alternatively provides the finished product with greater resistance to oxidation or corrosion, for example. The skin can also be made from a material that has a different composition than the core.

〔Effect of the invention〕

An important benefit of applying a coating to the carrier that transfers to the product is that the carrier can be made from inexpensive, relatively unreactive metals, and therefore any method of coating the carrier can be employed. be able to. Furthermore, even methods which are unfavorable to the material of the product to which the coating is to be transferred (methods in which the material of the product may be attacked) can be used, such as immersion in a chemical plating solution.

Yet another benefit is that, at least for straight holes, it is no longer necessary to use a rapid spray method. Spraying methods are always difficult, especially in the case of holes, where it is particularly difficult to obtain a uniform thickness due to the occlusion of the surface to be coated.

Thus, the method of the invention allows for multiple coatings on a single product or by laminating them in the appropriate reverse order on a single carrier.

[Brief explanation of drawings]

FIG. 1 and FIGS. 1a, b, and c are views showing a method according to a first embodiment of the present invention; FIGS. 2 and 2a, b, and c are views showing a second embodiment of the present invention; Third
Figures 4 and 4a, b, and c are diagrams showing still other embodiments, and Figures 5 and 6 show a method for manufacturing a product having cooling passages. The figure shown in FIG. 7 is a diagram showing a turbine blade having a cooling passage as described above. 10...Product, 12...Holding body, 14...Coating, 16...Product, 22...Holding core, 24...
Coating, 26... filler, 28... holding body, 30...
...Coating, 36, 38...Article, 40...Product, 11
0... Gas turbine engine combustion chamber wall, 11
2... Skin, 114... Holding plate, 118... Filler, 126... Turbine blade, 128...
Wing section of turbine blade, 130...skin.

Claims (1)

Claims: 1. In a method of forming a composite article 10 having a predetermined shape by applying a coating 14 to the surface of a substantially rigid component; (b) applying a coating 14 on the surface of the holder, the combination of holder and coating being substantially rigid, and the coating being opposite to the holder; (c) combining the part and the holder so that the complementary surface of the part and the surface of the coating come into contact with each other; (d) consisting of hot homogeneous compression of the parts and holder thus assembled with sufficient heat and pressure to join the adjoining and mutually complementary surfaces of said parts and sheathing to form a composite product; Method. 2. A method according to claim 1, characterized in that the holder 12 is at least partially removed from the composite product produced. 3. A method according to claim 1 or 2, characterized in that the surface of the component 10 and the complementary surface of the holder 12 are non-planar. 4. A method according to claim 1, 2 or 3, characterized in that two or more coatings are applied to the holder in the opposite order to the desired order on the product. 5 Applying a coating to the holder 36 in the form of spaced apart sections 38, hot-uniformly compressing the holder onto the product within said spacing, and then removing the portion of the holder 36 covering the coating. The method according to claim 1, 2 or 3, characterized in that: 6 Items 1 and 2 characterized in that a filler 26 is placed between the holder 28 and the covering 30.
3. The method according to any one of Section 3, Section 3, Section 4, or Section 5. 7 creating grooves 116 in the surface of coating 112;
Before assembling the part and the holder, the groove is filled with a removable material 118, and after the part and the holder are hot-uniformly compressed, the removable material is removed, leaving a passage in the product. The method according to claim 1, 2 or 3, characterized in that: 8. A method according to claim 7, characterized in that the coating consists of compacted particles. 9. A method according to claim 8, characterized in that the particles are metallic. 10 Claims 1, 2, 3, 4, 5, 6, 7, 8, or The method described in any of paragraph 9. 11 Claims 1, 2, and 3, characterized in that the coating consists of an abrasion-resistant outer skin.
Paragraph 4, Paragraph 5, Paragraph 6, Paragraph 7, Paragraph 8, Paragraph 9
or the method according to paragraph 10.