JP4504691B2 - Turbine parts and gas turbines - Google Patents

Description

  The present invention uses a green compact electrode formed by compression molding a metal powder, a metal compound powder, or a ceramic powder as an electrode, and generates a pulsed discharge between the electrode and the energy. The present invention relates to a turbine component in which a film made of an electrode material or a material in which the electrode material reacts with discharge energy is formed, and a gas turbine incorporating the turbine component.

A technique for improving the corrosion resistance and wear resistance by coating the surface of a metal material by a submerged electric discharge machining method is already known.
An example of the technique is as follows.
For example, this electrode material is deposited on a workpiece by performing pulse discharge in liquid with an electrode formed by mixing WC (tungsten carbide) and Co powder and compression molding, and thereafter, another electrode (for example, copper electrode, graphite) Electrode) discloses a method of performing remelting electric discharge machining to obtain higher hardness and higher adhesion (see Patent Document 1).
That is, using a mixed powder electrode of WC-Co, electric discharge machining is performed on the workpiece (base material S50C) in a liquid, WC-Co is deposited on the workpiece (primary machining), and then a copper electrode or the like. Remelting processing (secondary processing) is performed with electrodes that are not so consumed.
As a result, in the primary processing, the deposited structure had a hardness (Vickers hardness Hv) of about Hv = 1410, and there were many cavities, but the remelting processing of the secondary processing eliminated the cavities of the coating layer, Hardness is also improved with Hv = 1750. By this method, a coating layer that is hard and has good adhesion to a steel material as a workpiece can be obtained.

However, in the above-described method, it is difficult to form a coating layer having strong adhesion on the surface of a sintered material such as a cemented carbide as a workpiece.
In this regard, according to the study of the present inventors, when a material such as Ti that forms hard carbide is used as an electrode and a discharge is generated between the workpiece and the workpiece, a strong hard film is formed on the workpiece without remelting. It was found that it can be formed on a metal surface.
This is because TiC is produced by the reaction between the electrode material consumed by the discharge and carbon C, which is a component in the machining fluid.

In addition, when a metal hydride green compact such as TiH ₂ (titanium hydride) is used as an electrode and a discharge is generated between it and the workpiece, it is faster and has better adhesion than when a material such as Ti is used. A technique capable of forming a hard film is disclosed (see Patent Document 2).
Furthermore, using a green compact made by mixing other metal or ceramics with a hydride such as TiH ₂ (titanium hydride) as an electrode, various properties such as hardness, wear resistance, etc. are generated when electric discharge is generated between the workpiece. There is also disclosed a technique capable of quickly forming a hard coating having a thickness.

As another technique, it is disclosed that a surface-treated electrode having high strength can be manufactured by pre-sintering (see Patent Document 3).
That is, when manufacturing an electrode for discharge surface treatment composed of a powder obtained by mixing WC powder and Co powder, a green compact obtained by mixing and compressing WC powder and Co powder is obtained by mixing WC powder and Co powder. It may be only compression molded, but if the wax is mixed and then compression molded, the moldability of the green compact is improved.
In this case, the wax is an insulating substance, and if it remains in the electrode in large quantities, the electrical resistance of the electrode increases and the discharge performance deteriorates. Therefore, the wax is removed by heating the green compact electrode in a vacuum furnace. is doing.
At this time, if the heating temperature is too low, the wax cannot be removed, and if the temperature is too high, the wax becomes soot and deteriorates the purity of the electrode. It is necessary to keep below.
Then, the green compact in the vacuum furnace is heated by a high-frequency coil or the like to give a strength that can withstand machining, and is fired to a hardness of, for example, white ink so as not to be hardened (this is a pre-sintered state) Called).
In this case, bonding proceeds at the contact portion between the carbides, but the bonding is weak because the sintering temperature is relatively low and the main sintering is not achieved.
It has been found that when a discharge surface treatment is performed with such an electrode, a dense and homogeneous film can be formed.

  Although the above-mentioned conventional techniques are characterized by the hardness and adhesion of the film, the wear resistance, the rapidity of the film formation, and the denseness and homogeneity of the film in any case, the film thickness is sufficient. There is nothing and further improvement is required.

However, recently, there is an increasing demand for a simple and quality thick film forming technique.
Since the conventional discharge surface treatment as described above has focused on forming a hard coating, the electrode material is a hard ceramic material, or C (carbon which is a component of oil in the machining fluid depending on the energy of discharge. The main component is a material that forms a hard carbide through a chemical reaction.
However, hard materials generally have characteristics such as a high melting point and poor heat conduction, and a thin film of about 10 μm can be formed densely, but a dense thick film of several hundred μm or more is extremely difficult to form. there were.
The literature based on the study by the present inventors shows that a thick film of about 3 mm can be formed using a WC-Co (9: 1) electrode (see Non-Patent Document 1). There are problems such as being unstable and difficult to reproduce, seemingly dense with metallic luster, but with a lot of pores and a brittle coating, and being weak enough to be removed when rubbed strongly with metal pieces. Yes, it is a difficult level for practical use.

As a technique for thickening a general coating, there are so-called welding and thermal spraying.
Welding (herein referred to as overlay welding) is a method in which the material of the welding rod is melted and adhered to the workpiece by electric discharge between the workpiece and the welding rod. Thermal spraying is a method in which a metal material is melted and sprayed onto a workpiece to form a coating.
These methods are techniques widely used for gas turbines used in aircraft engines and the like.
Any of these methods is a manual operation and requires skill, so that it is difficult to line the operation and there is a disadvantage that the cost increases.

An example thereof will be described with reference to FIGS.
FIG. 15 is a low-pressure turbine blade of a gas turbine engine.
The turbine blades are arranged side by side with a large number of blades, each of which is installed with the root portion fixed, and the tip portion is not fixed, and the adjacent blades are in contact with each other.
Since the tip portion rubs and wears when the gas turbine engine is operated, it usually has a material that exhibits wear resistance from a low temperature to a high temperature of 700 ° C. or higher.
A portion where the material having wear resistance is built up is shown in FIG.
This build-up processing is conventionally performed by welding or thermal spraying. However, pre-processing and post-processing are necessary, and the processing itself is a work that requires skill by manpower.

FIG. 17 shows a state where the overlay is performed by welding.
There is a lot of extra meat, and work to adjust the shape as a post process is required.
Also, welding is a difficult process to put in the flow production line, and is a process of performing welding work outside the line and putting the welded parts into machining on the line.
Similarly, when overlaying is performed by thermal spraying, previous and subsequent steps are required, and processing is difficult.
In the case of thermal spraying, as a pretreatment, a masking process is performed so that the thermal spray material is not applied to a place where a coating is not desired, and after the thermal spraying process, a process for adjusting the shape is necessary as in the case of welding.

Although the manufacturing problem of the low-pressure turbine blade has been described, the same problem occurs in the high-pressure turbine blade.
Gas turbine engines are used with regular repairs because their blades wear during operation.
Turbine blades and compressor blades wear due to rubbing against the casing portion on the fixed side, so repair is performed by overlay welding.
Turbine blades and compressor blades have many thin structures, and in a processing method in which heat concentrates like welding, there is a problem that deformation, cracking, etc. occur and yield decreases.
In particular, the high-pressure turbine blade is made of a material such as a single crystal material or a unidirectionally solidified alloy, and there is a problem that it quickly breaks when heat is concentrated.
JP-A-5-148615 Japanese Patent Laid-Open No. 9-192937 Japanese Patent No. 3227454 "Formation of thick film by discharge surface treatment (EDC)" Akihiro Goto et al., Mold Technology, (1999), Nikkan Kogyo Shimbun

  The present invention has been made in view of the above, and discloses a discharge surface treatment technique for forming a thick film, which has been difficult in conventional coating by submerged pulse discharge treatment, and is manufactured by techniques such as conventional welding and thermal spraying. Alternatively, it aims to provide a repaired gas turbine engine at low cost and high quality.

  The turbine component according to claim 1 generates a pulsed discharge in the working fluid or in the air between the metal powder or the green compact electrode obtained by compression molding the powder of the metal compound, and the discharge energy causes the above-mentioned A turbine component characterized in that, based on an electrode material supplied from a green compact electrode, a coating containing a predetermined proportion of carbide and a metal component that is not carbide is formed on a predetermined portion of the surface.

In the turbine component of the present invention, the coating is formed by processing performed by a machine that does not require manual labor, so the quality is stable and the cost can be reduced.
In addition, even parts made of materials that are easily broken due to intensive heat input do not break or deform, and are highly reliable parts.
A gas turbine incorporating such a high-reliability and low-cost component can greatly reduce the cost and has high reliability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1
FIG. 1 is a cross-sectional view showing the concept of a discharge surface treatment electrode and a manufacturing method thereof according to Embodiment 1 of the present invention.
In FIG. 1, a space surrounded by the upper punch 103 of the mold, the lower punch 104 of the mold, and the die 105 of the mold is made of Cr ₃ C ₂ (chromium carbide) powder 101 and Co (cobalt) powder 102. The mixed powder is filled.
Then, a green compact is formed by compression molding the mixed powder. In the discharge surface treatment, this green compact is used as a discharge electrode.

In the production of electrodes, as described above, conventionally, the discharge surface treatment has been focused on the formation of a hard film, particularly the formation of a hard film at a temperature close to room temperature, and a film mainly composed of hard carbide is formed. That is the current situation.
In the technique of forming a coating containing such a carbide as a main component, a dense coating can be formed uniformly, but there is a problem that the thickness of the coating cannot be increased to about several tens of μm or more. This is as described above.

However, according to experiments by the present inventors, it has been found that the coating can be made thicker as a material that does not form carbides or hardly forms carbides is added to the component of the electrode material.
Conventionally, a large proportion of materials that easily form carbides are included. For example, when a material such as Ti is included in an electrode, a chemical reaction is caused by discharge in oil, and the coating is called TiC (titanium carbide). It becomes hard carbide.
As the surface treatment progresses, the material of the workpiece surface changes from steel (when processed into steel) to TiC which is ceramic, and characteristics such as heat conduction and melting point change accordingly.
However, when a material that is not carbonized or hardly carbonized is added to the electrode, the film does not become a carbide, and a phenomenon occurs in which the material that remains in the film as a metal increases.
And, it has been found that the selection of the electrode material has a great significance for thickening the coating. In this case, it is natural that the hardness, the denseness, and the uniformity are satisfied, and it is a premise for forming a thick film.

As shown in FIG. 1, a powder obtained by mixing Cr ₃ C ₂ (chromium carbide), which is a carbide, and Co (cobalt), which is a material that is difficult to form carbide, is compression-molded, and then heated to increase the electrode strength. When an electrode is manufactured, the ease of forming a thick film changes by changing the amount of Co that is difficult to form carbides.
FIG. 2 shows this state.
The powder used to produce the electrode was compressed so that the compression pressing pressure was about 100 MPa, and the heating temperature was in the range of 400 ° C to 800 ° C.
The heating temperature was increased as the amount of Cr ₃ C ₂ (chromium carbide) was increased, and the temperature was decreased as the amount of Co (cobalt) was increased.
This is because when the amount of Cr ₃ C ₂ (chromium carbide) is large, the manufactured electrode tends to become brittle and immediately collapses even when heated at a low temperature, whereas when the amount of Co (cobalt) is large, the heating temperature This is because the strength of the electrode was likely to increase even when the thickness was low.
At the time of pressing, a small amount (2% to 3% by weight) of wax was mixed with the powder to be pressed in order to improve the moldability. The wax is removed on heating.
Cr ₃ C ₂ (chromium carbide) used powder with a particle size of about ₃ μm to 6 μm, and Co used powder with a particle size of about 4 μm to 6 μm. The base material is Cr ₃ C ₂ (chromium carbide).
The discharge pulse used has a waveform as shown in FIG. 3, and the pulse conditions are: peak current value ie = 10 A, discharge duration (discharge pulse width) te = 64 μs, rest time to = 128 μs, area of 15 mm × 15 mm A coating was formed on the electrodes of
The processing time is 15 minutes. The polarity was negative for the electrode and positive for the workpiece. In FIG. 3, when the electrode has a negative polarity and the workpiece has a positive polarity, the vertical axis is displayed on the upper side.

  When a film is formed based on such a pulse condition, the thickness of the film formed on the workpiece varies depending on the weight percentage of Co in the manufactured electrode. According to FIG. When the amount is low, the film thickness of about 10 μm gradually increases from the Co content of about 30% by volume, and increases from the point where the Co content exceeds 50% by volume to nearly 10,000 μm. .

This will be described in more detail.
When a film is formed on the workpiece based on the above conditions, when Co in the electrode is 0%, that is, when Cr ₃ C ₂ (chromium carbide) is 100% by weight, The limit is about 10 μm, and the thickness cannot be increased further.
Moreover, the state of the thickness of the coating film with respect to the processing time when there is no material that hardly forms carbide in the electrode is as shown in FIG.
According to FIG. 4, at the beginning of the treatment, the film grows and thickens with time and saturates at some point (about 5 minutes / cm ² ).
After that, the film thickness does not grow for a while, but if the treatment is continued for a certain time (about 20 minutes / cm ² ) or more, the thickness of the film starts to decrease and finally the film height becomes minus, that is, changes to digging. .
However, the film is present even in the dug state, and the thickness itself is about 10 μm, which is almost the same as the state processed in an appropriate time. Therefore, the processing time between 5 minutes and 20 minutes is considered appropriate.

Returning to FIG. 2, it becomes possible to increase the thickness as the amount of Co, which is a material that is not easily carbonized in the electrode, and when the amount of Co in the electrode exceeds 30% by volume, the thickness of the formed film starts to increase, It has been found that when it exceeds 40% by volume, a thick film can be easily formed stably.
The graph of FIG. 2 shows that the film thickness increases smoothly from about 30% by volume of Co, but this is an average value obtained by performing a plurality of tests. Is about 30% by volume, there are cases where the film does not swell thickly, or even when it swells thickly, the film strength is weak, that is, it may be removed by rubbing strongly with a metal piece, etc. Not stable. More preferably, the Co content exceeds 50% by volume.

  By increasing the amount of the material remaining as a metal in the coating in this way, a coating containing a metal component that is not carbide can be formed, and a thick film can be easily formed stably. The volume% here is a ratio of a value obtained by dividing the weight of each powder to be mixed by the density of each material, and is a ratio of the volume occupied by the material in the volume of the material of the whole powder.

FIG. 5 shows a photograph of the coating formed when the Co content in the electrode is 70% by volume. This photograph illustrates the formation of a thick film.
In the photograph shown in FIG. 5, a thick film of about 2 mm is formed.
This film is formed in a processing time of 15 minutes, but if the processing time is increased, a thicker film can be formed.

In this way, by using an electrode containing 40% by volume or more of a material that is difficult to carbonize or not carbonized, such as Co, in the electrode, a thick film can be stably formed on the workpiece surface by discharge surface treatment. .
In the above description, the case where Co (cobalt) is used as a material that hardly forms carbides has been described. However, Ni (nickel), Fe (iron), and the like are materials that can obtain similar results, and are used in the present invention. Is preferred.

The thick film here means a dense structure in which the inside of the tissue (which is a film formed by pulsed discharge, so that the outermost surface has poor surface roughness and does not appear glossy) has a metallic luster. It is a simple film.
Even when there are few materials such as Co (cobalt) that are difficult to form carbides, deposits may rise when the strength of the electrode is reduced.
However, such a deposit is not a dense film, but can be easily removed by rubbing with a metal piece or the like. The deposited layer described in the above-mentioned Patent Document 1 is such a non-dense film and can be easily removed by rubbing with a metal piece or the like.

In the above description, the case where Cr ₃ C ₂ (chromium carbide) and Co powders are compression-molded and heated to form an electrode has been described. However, a compression-molded green compact may be used as the electrode. In some cases.
However, in order to form a dense thick film, the electrode may not be too hard or too soft, and an appropriate hardness is required.
In general, heat treatment is required.
Heating the green compact leads to maintenance and solidification of the molding.
The hardness of the electrode has a correlation with the strength of bonding of the powder of the electrode material, and is related to the supply amount of the electrode material to the work side by discharge.
When the electrode is hard, the bonding of the electrode material is strong, so that only a small amount of the electrode material is released even when a discharge occurs, and a film cannot be formed sufficiently.
Conversely, when the electrode hardness is low, the bonding of the electrode material is weak, so when a discharge occurs, a large amount of material is supplied, and if this amount is too large, it should be melted sufficiently with the energy of the discharge pulse. It is impossible to form a dense film.
When the same raw material powder is used, parameters affecting the hardness of the electrode, that is, the bonding state of the material of the electrode, are the pressing pressure and the heating temperature.

In this example, about 100 MPa was used as an example of the press pressure, but when this press is raised, the same hardness can be obtained even if the heating temperature is lowered.
Conversely, it was found that when the press pressure is lowered, the heating temperature needs to be set higher.
This fact applies not only to this embodiment but also to other embodiments in the present invention.
In this embodiment, the test result under one condition is shown as an example of the discharge condition. However, it is needless to say that the same result can be obtained under other conditions although the thickness of the film is different. This fact applies not only to this embodiment but also to other embodiments of the present invention.

FIG. 6 is a schematic configuration diagram showing the discharge surface treatment apparatus according to the first embodiment of the present invention.
As shown in FIG. 6, the discharge surface treatment apparatus according to the present embodiment is the above-described discharge surface treatment electrode, and compression-molds a powder containing 40% by volume or more of a metal material that does not form carbide or is difficult to form. The electrode 203 made of the green compact or the green compact obtained by heat-treating the green compact, the oil as the machining fluid 205, and the electrode 203 and the moving blade 204 of the gas turbine as the workpiece are immersed in the machining fluid. Or a machining liquid supply device for supplying the machining liquid 205 between the electrode 203 and the workpiece 204, and a discharge surface treatment power source for generating a pulsed discharge by applying a voltage between the electrode 203 and the workpiece 204 206.
Here, the electrode 203 is composed of, for example, Cr ₃ C ₂ (chromium carbide) powder 201 and Co (cobalt) powder 202, and contains, for example, 70% by volume of Co, which is a material that hardly forms carbide.
Note that members that are not directly related to the present invention, such as a driving device that controls the relative position between the electrode 203 and the workpiece 204, are omitted.

In order to form a coating film on the surface of the workpiece by the discharge surface treatment apparatus, the electrode 203 and the moving blade 204 of the gas turbine as the workpiece are arranged to face each other in the machining liquid 205, and the discharge surface treatment power source 206 is formed in the machining liquid. A gas turbine, which is a workpiece, generates a pulsed discharge between the electrode 203 and the workpiece 204 from the electrode 203, forms a coating of the electrode material on the surface of the workpiece by the discharge energy, or forms a coating of a substance reacted with the electrode material by the discharge energy Formed on the surface of the blade.
The polarity is negative on the electrode side and positive on the workpiece side. An arc column 207 for discharge is generated between the electrode 203 and the workpiece 204 as shown in FIG.

Using the above-described discharge surface treatment apparatus, it is possible to form a coating, for example, an abrasive (scraping away) film on the tip of the compressor blade of the gas turbine, on the moving blade 204 of the gas turbine that is the workpiece.
Here, by adding Cr ₃ C ₂ (chromium carbide) powder, which is a hard material, to Co (cobalt) powder, the coating hardness is increased and a coating with high hardness is formed when the gas turbine blade is built up. However, it is needless to say that not only a combination of Co (cobalt) powder and Cr ₃ C ₂ (chromium carbide) powder is required for the gas turbine part because various functions are required for each part.

Embodiment 2
FIG. 7: is sectional drawing which shows the concept of the electrode for discharge surface treatment concerning Embodiment 2 of this invention, and its manufacturing method.
In FIG. 7, a mixed powder composed of Ti (titanium) powder 701 and Co (cobalt) powder 702 is filled in a space surrounded by the upper punch 703 of the mold, the lower punch 704 of the mold, and the die 705 of the mold. Is done. Then, a green compact is formed by compression molding the mixed powder.
In the discharge surface treatment, this green compact is used as a discharge electrode. The powder used to produce the electrode was compressed so that the compression pressing pressure was about 100 MPa, and the heating temperature was in the range of 400 ° C to 800 ° C.

In the first embodiment described above, the characteristics of film formation with an electrode manufactured by mixing Cr ₃ C ₂ (chromium carbide) powder as a carbide and Co (cobalt) powder as a metal have been described. In the example, a case where an electrode is manufactured by mixing Ti (titanium) powder and Co (cobalt) powder, which are metals, will be described.
Ti (titanium) and Co (cobalt) are both metals, but the difference is that Ti (titanium) is an active material and TiC (titanium carbide) which is a carbide in the atmosphere of electric discharge in oil as a working fluid. Co (cobalt) is a material that hardly forms carbides.

In the second embodiment, as in the first embodiment, the content of Ti (titanium) powder in the electrode is changed to 100% by volume of Ti (titanium) powder, that is, from the case where Co in the electrode is 0% by volume. ) The powder content was gradually increased, and the state of film formation was examined.
Here, as the Ti (titanium) powder, a powder having a particle size of about 3 μm to 4 μm was used, and as the Co (cobalt) powder, a powder having a particle size of about 4 μm to 6 μm was used.
Since Ti (titanium) is a sticky material, it is difficult to produce fine powder. TiH ₂ (titanium hydride), which is a brittle material, is pulverized with a ball mill to a particle size of 3 μm to 4 μm, and the powder is used. After compression molding, the mixture was heated to release hydrogen to obtain Ti powder.

When the electrode material was 100% by volume of Ti (titanium), the film was TiC (titanium carbide), and the film thickness was about 10 μm.
However, a thick film can be formed as the content of Co, which is a material that is not easily carbonized, is increased. If the Co content in the electrode exceeds 40% by volume, a thick film can be easily formed stably. There was found.
It has been found that it is preferable that the Co content in the electrode exceeds 50% by volume because a sufficiently thick film can be formed.
This result is almost the same as the result shown in the first embodiment.
This is because Ti (titanium) contained in the electrode becomes TiC (titanium carbide) which is a carbide in the atmosphere of discharge in oil as a working fluid, and the result is similar to mixing carbide from the beginning. It is guessed that it is to become.
When the components of the film were actually analyzed by X-ray diffraction, a peak indicating the presence of TiC (titanium carbide) was observed, but a peak indicating the presence of Ti (titanium) was not observed.

Therefore, even when an electrode is manufactured by mixing Ti (titanium) powder and Co (cobalt) powder, the electrode contains 40 vol% or more of Co (cobalt) powder as a material that is not easily carbonized or is not carbonized. By forming the electrode, a thick film can be stably formed on the workpiece surface by the discharge surface treatment.
In addition, according to the electrode of this material, titanium becomes titanium carbide (TiC) which is a hard material by electric discharge, so that it can be used as a wear-resistant coating. For example, the abrasive blade tip portion of the gas turbine compressor blade is scraped off. ) Can be used as a membrane.
In this embodiment, Co (cobalt) is used as an example of a material that is difficult to form a carbide constituting the electrode by mixing with Ti (titanium) powder. However, Ni (nickel), Fe ( Iron) is a material that can obtain the same result, and is suitable for use in the present invention.
Here, by putting Ti (titanium) powder into the electrode, TiC (titanium carbide) produced by reaction with the energy of discharge is put into the coating to increase the coating hardness and when the gas turbine blade is built up The purpose is to form a coating with high hardness, but gas turbine parts are required to have various functions for each part, so it is not only a combination of Co (cobalt) powder and Ti (titanium) powder. Not until.

Embodiment 3
FIG. 8: is sectional drawing which shows the concept of the electrode for discharge surface treatment concerning Embodiment 3 of this invention, and its manufacturing method.
In FIG. 8, the space surrounded by the upper punch 803 of the mold, the lower punch 804 of the mold, and the die 805 of the mold is filled with a mixed powder composed of Cr (chrome) powder 801 and Co (cobalt) powder 802. Is done. Then, a green compact is formed by compression molding the mixed powder. In the discharge surface treatment, this green compact is used as a discharge electrode. The powder used to produce the electrode was compressed so that the compression pressing pressure was about 100 MPa, and the heating temperature was in the range of 400 ° C to 800 ° C.
In the second embodiment, the case of forming a film with an electrode in which Ti (titanium) powder, which is a metal that easily forms carbides, and Co (cobalt) powder, which is a material that is not easily carbonized, has been described. Now, a case will be described in which an electrode is manufactured by mixing Cr (chromium) powder, which is a metal forming carbide, and Co (cobalt) powder, which is a material difficult to form carbide.
In the third embodiment, as in the first embodiment, the Cr (chromium) powder content in the electrode is changed to 100 vol% of Cr (chromium) powder, that is, Co (cobalt) is changed from the case where Co in the electrode is 0 vol%. ) The powder content was gradually increased, and the state of film formation was examined. Here, as the Cr (chromium) powder, a powder having a particle size of about 3 μm to 4 μm was used, and as the Co (cobalt) powder, a powder having a particle size of about 4 μm to 6 μm was used.

When the electrode material was 100% by volume of Cr (chromium), the film thickness was about 10 μm. However, when the film component was analyzed by X-ray diffraction, a peak indicating the presence of Cr ₃ C ₂ (chromium carbide) and a peak indicating the presence of Cr (chromium) were observed. That is, although Cr (chromium) is a material that is easily carbonized, it is less easily carbonized than a material such as Ti (titanium), and a part of the electrode contains Cr (chromium). Becomes a carbide, and a part of the film remains a metallic Cr (chromium).

Even when Cr (chromium) is used as an electrode component, it has been found that the coating can be made thicker as the content of Co, which is a material that is not easily carbonized, is increased.
However, the ratio may be smaller than that in the case where the electrode component contains carbide or the material that is very likely to become carbide as in the case of the first and second embodiments. It has been found that a thick film can be easily formed when the Co content in the medium exceeds 20% by volume.
FIG. 9 shows the change in the thickness of the film when the amount of Co is changed. The discharge pulse conditions used were the same as those in Example 1 and Example 2, peak current value ie = 10 A, discharge duration (discharge pulse width) te = 64 μs, pause time to = 128 μs, 15 mm × A film was formed with an electrode having an area of 15 mm.
The polarity was negative for the electrode and positive for the workpiece. Processing time is 15 minutes.

As described above, there is a difference in easiness of carbonization among materials that easily form carbides, and a material that is hard to carbonize tends to form a thicker film.
This is presumably because the condition for forming the thick film is that there is a predetermined amount of the material that does not become carbides but remains in the metal in the coated material.
Considering the results shown in the first to third embodiments, the necessary condition for forming a dense thick film is that the ratio of the material remaining as metal in the coating is about 30% or more by volume. Conceivable.
In addition, there is no clear data on the ease of carbonization of metal materials in the discharge atmosphere in oil as the working fluid, but it is shown in the Ellingham diagram when considered from the experimental data described above. The amount of energy required for carbonization is considered to be helpful.
The Ellingham diagram shows that Ti (titanium) is very easily carbonized, and it can be said that Cr (chromium) is harder to carbonize than Ti. Among materials that easily form carbides, Ti and Mo (molybdenum) are easily carbonized, and Cr (chromium) and Si (silicon) are considered to be relatively difficult to carbonize. The results are in good agreement.

  As described above, even when an electrode is manufactured by mixing Cr (chromium) powder and Co (cobalt) powder, 40 vol. Of Co (cobalt) powder as a material which is not easily carbonized or is not carbonized in the electrode. By making the electrode contained at least%, a thick film can be stably formed on the workpiece surface by the discharge surface treatment. In this case, a thick film can be stably formed on the surface of the work, particularly if the electrode contains 20% by volume or more of Co.

In this embodiment, Co (cobalt) is used as an example of a material that is difficult to form carbides constituting the electrode by mixing with Cr (chromium) powder. However, Ni (nickel), Fe ( Iron) is a material that can obtain the same result, and is suitable for use in the present invention.
Here, Cr (Chromium) powder is put into the electrode, Cr ₃ C ₂ (chromium carbide) produced by reaction with the energy of discharge is put into the coating to increase the coating hardness and build up of the gas turbine blade In this case, it is possible to form a film that exhibits lubricity in a high-temperature environment by forming a highly hard film and leaving Cr (chromium) in the film.
Cr (chromium) is oxidized in a high temperature environment to become Cr ₂ O ₃ (chromium oxide), and since it exhibits lubricity, the effect of wear resistance is effectively exhibited.
The film formed by this electrode becomes a film that exhibits wear resistance due to its lubricity in a high temperature environment, and a film that can be applied to a sliding portion of a high temperature member of a turbine can be formed.
In the present embodiment, a reliable turbine component having a long life can be provided by forming a coating having excellent wear resistance at high temperatures on the gas turbine component.
This is effective for the part of the low-pressure turbine blade shown in FIG. 16 and the part for positioning the turbine stationary blade as shown in FIG.
As a result, it is possible not only to manufacture and repair turbine parts easily and to improve the quality, but also to increase the reliability of the parts, thereby supplying a high-quality gas turbine.

Embodiment 4
FIG. 11: is sectional drawing which shows the concept of the electrode for discharge surface treatment concerning Embodiment 4 of this invention, and its manufacturing method.
In FIG. 11, in the space surrounded by the upper punch 1005 of the mold, the lower punch 1006 of the mold, and the die 1007 of the mold, Mo (molybdenum) powder 1001, Cr (chromium) powder 1002, Si (silicon) powder A mixed powder composed of 1003 and Co (cobalt) powder 1004 is filled. The blending ratio of the powder is “Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) residue”.
In this case, the volume percentage of Co (cobalt) is about 50%.
Then, a green compact is formed by compression molding the mixed powder. In the discharge surface treatment, this green compact is used as a discharge electrode.

The ratio of “Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) residue” is used as a material for wear resistance in high temperature environments. It is a combination.
The electrode blended in such a ratio is resistant to wear because the hardness of the material and Cr ₂ O ₃ (chromium oxide) formed by oxidation of Cr (chromium) under high temperature environment exhibit lubricity. Demonstrate the effect.
The press pressure for compressing and molding the powder in producing the electrode was about 100 MPa, and the heating temperature was in the range of 600 ° C to 800 ° C.
At the time of pressing, in order to improve moldability, a small amount (2% to 3% by weight) of wax was mixed with the powder to be pressed. The wax is removed on heating.
As the powder, a powder having a particle size of about 2 μm to 6 μm was used for each material.
The discharge pulse conditions used were a peak current value ie = 10 A, a discharge duration (discharge pulse width) te = 64 μs, a rest time to = 128 μs, and an electrode having an area of 15 mm × 15 mm. The polarity was negative for the electrode and positive for the workpiece.

By using the electrode manufactured as described above, the same discharge surface treatment as that in FIG. 6 can be performed.
When a coating film is formed on the workpiece surface by the pulse discharge treatment in the liquid using the discharge surface treatment apparatus, a thick coating film can be formed on the workpiece material without causing distortion due to the pulse discharge in the oil that is the working fluid. It was. In addition, it was confirmed that the formed film exhibited wear resistance in a high temperature environment, and a high-quality thick film could be formed.
A film having various functions such as wear resistance can be obtained by forming a film on the work surface by pulse discharge treatment in liquid using an electrode prepared by mixing materials in the above-described ratio. Other materials include “Cr (chromium) 25 wt%, Ni (nickel) 10 wt%, W (tungsten) 7 wt%, Co (cobalt) residue”, or “Cr (chromium) 20 wt%, Ni ( Nickel), 10% by weight, W (tungsten) 15% by weight, and Co (cobalt) residue ”.
Since stellite is excellent in corrosion resistance and high temperature hardness, it is a material that is usually subjected to coating treatment by welding or the like on a portion where these properties are required, and is suitable for coating treatment when corrosion resistance and high temperature hardness are required.
"Cr (chromium) 15 wt%, Fe (iron) 8 wt%, Ni (nickel) remaining", "Cr (chromium) 21 wt%, Mo (molybdenum) 9 wt%, Ta (tantalum) 4 wt% , Ni (nickel) residue ”,“ Cr (chromium) 19 wt%, Ni (nickel) 53 wt%, Mo (molybdenum) 3 wt%, (Cd + Ta) 5 wt%, Ti (titanium) 0.8 wt%, Nickel-based materials such as “Al (aluminum) 0.6 wt%, Fe (iron) residue” are materials that exhibit heat resistance, and are suitable for coating processing when heat resistance is required.

“Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) residue”, “Cr (chromium) 25 wt%, Ni (nickel) 10 wt%, W Materials such as (tungsten) 7% by weight, Co (cobalt) residue "," Cr (chromium) 20% by weight, Ni (nickel) 10% by weight, W (tungsten) 15% by weight, Co (cobalt) residue " Cr ₂ O ₃ (chromium oxide) formed by oxidation of Cr (chromium) in a high-temperature environment is a material that exhibits an effect of wear resistance because it exhibits lubricity. It is effective for the part of the moving blade and the part for positioning the turbine stationary blade.
"Cr (chromium) 15 wt%, Fe (iron) 8 wt%, Ni (nickel) remaining", "Cr (chromium) 21 wt%, Mo (molybdenum) 9 wt%, Ta (tantalum) 4 wt% , Ni (nickel) residue ”,“ Cr (chromium) 19 wt%, Ni (nickel) 53 wt%, Mo (molybdenum) 3 wt%, (Cd + Ta) 5 wt%, Ti (titanium) 0.8 wt%, Nickel-based materials such as “Al (aluminum) 0.6 wt%, Fe (iron) residue” are materials that exhibit heat resistance, and are suitable for repairing high-pressure turbine blades and the like.
In particular, since Cr and Mo are materials that become oxides and exhibit lubricity at high temperatures, the coating formed by this electrode becomes a coating that exhibits wear resistance due to its lubricity in a high-temperature environment, and the high temperature of the turbine. It can be applied to a sliding portion of a member.
In addition, the high-pressure turbine blade is made of a material such as a single crystal material or a unidirectionally solidified alloy, and there is a problem that the high-pressure turbine blade breaks as soon as heat is concentrated.
Since the method of the present invention is a method of forming a coating film by pulsed discharge, the coating film can be formed without generating heat even if a material that is easily cracked does not concentrate heat.
As a result, it is possible not only to manufacture and repair turbine parts easily and to improve the quality, but also to increase the reliability of the parts, thereby supplying a high-quality gas turbine.

Embodiment 5
FIG. 12: is sectional drawing which shows the concept of the electrode for discharge surface treatment concerning Embodiment 5 of this invention, and its manufacturing method.
In FIG. 12, the space surrounded by the upper punch 1103 of the mold, the lower punch 1104 of the mold, and the die 1105 of the mold is filled with Co-based alloy powder (Co, Cr, Ni alloy powder) 1101. The
Then, a green compact is formed by compression molding the mixed powder. In the discharge surface treatment, this green compact is used as a discharge electrode.
The powder 1101 is obtained by powdering an alloy (sterite) made by mixing Co (cobalt), Cr (chromium), Ni (nickel) or the like at a predetermined alloy ratio.
Examples of the method for forming the powder include an atomizing method and a method of pulverizing the alloy with a mill.
In either method, each powder particle is an alloy (in the case of FIG. 12, a Co-based alloy powder).
The alloy powder is compression molded by a die 1105 and punches 1103 and 1104.
In some cases, heat treatment may be performed thereafter to increase the strength of the electrode.
Here, an alloy powder having an alloy ratio of “Cr (chromium) 20 wt%, Ni (nickel) 10 wt%, W (tungsten) 15 wt%, Co (cobalt) 55 wt%” was used.
In this case, the volume percentage of Co (cobalt) is 40% or more.

The press pressure for compressing the powder was about 100 MPa, and the heating temperature was in the range of 600 ° C to 800 ° C.
At the time of pressing, in order to improve moldability, a small amount (2% to 3% by weight) of wax was mixed with the powder to be pressed. The wax is removed on heating.
As the powder, a powder having a particle size of about 2 μm to 6 μm was used for each material. The discharge pulse conditions used were a peak current value ie = 10 A, a discharge duration (discharge pulse width) te = 64 μs, a rest time to = 128 μs, and an electrode having an area of 15 mm × 15 mm. The polarity was negative for the electrode and positive for the workpiece.

FIG. 13 is a schematic configuration diagram showing the state of the discharge surface treatment according to the present embodiment configured using the electrode manufactured as described above.
As shown in FIG. 13, the discharge surface treatment apparatus immerses the electrode 1202 made of the alloy powder having the above-described alloy ratio, the oil that is the working liquid 1204, the electrode 1202 and the workpiece 1203 in the working liquid, or the electrode. Discharge surface treatment for generating a pulsed discharge by applying a voltage between a machining fluid supply device 1208 that supplies a machining fluid 1204 between 1202 and a workpiece 1203, and an electrode 1202 and a turbine blade 1203 that is a workpiece. And a power source 1205.
Electrode 1202 is made of alloy powder 1201.
Note that members that are not directly related to the present invention, such as a driving device that controls the relative positions of the discharge surface treatment power source 1205 and the workpiece 1203, are omitted.

In order to form a coating film on the workpiece surface with this discharge surface treatment apparatus, the turbine blade 1203 as the electrode 1202 is disposed oppositely in the machining liquid 1204, and the electrode 1202 is connected to the electrode 1202 from the discharge surface treatment power source 1205 in the machining liquid. A pulsed discharge is generated between the workpiece 1203 and the electrode material by the discharge energy or a coating of the substance that the electrode material has reacted by the discharge energy is formed on the surface of the turbine blade that is the workpiece.
The polarity is negative on the electrode side and positive on the workpiece side. As shown in FIG. 13, the arc column 1206 of discharge is generated between the electrode 1202 and the workpiece 1203.
The electrode material is supplied to the workpiece side for each discharge. Although the electrode material is made of powder, it is made of a powdered alloy, so the material is uniform, and even when supplied to the electrode 1202, there is no variation in material.
As a result, it is possible to form a high-quality film without variation in components due to non-uniformity of the electrode material.

When an electrode having a predetermined composition is manufactured by mixing powders of respective materials, there may be a problem that a constant material performance cannot be obtained due to variations in mixing of the powders.
According to the researches of the present inventors, it is extremely difficult to mix a plurality of powders completely and uniformly when an electrode having a predetermined composition is produced by mixing powders of respective materials. It has been found that variation among individuals or variation depending on location can occur within one electrode.
This has a great effect in the case of an electrode containing a material that easily forms carbides.
For example, when an easily carbonized material such as Mo (molybdenum) or Ti (titanium) is unevenly distributed like an alloy described later, it is difficult to form a thick film only at that portion. There is a problem that the film thickness is not uniform together with the components in the film.

However, as shown in the present embodiment, it is possible to eliminate variations in electrode components by making a powder of an alloy material in which a plurality of elements are alloyed at a predetermined ratio and manufacturing an electrode from the powder. It became. Then, by performing discharge surface treatment using the electrode, it is possible to stably form a thick film on the workpiece surface, and the film component of the formed film can be made uniform. It was.
Therefore, a coating can be formed on the turbine blade 1203 that is a workpiece by using the discharge surface treatment apparatus using the electrode as described above.

  In the above, a material obtained by pulverizing an alloy having an alloy ratio of “Cr (chromium) 20 wt%, Ni (nickel) 10 wt%, W (tungsten) 15 wt%, Co (cobalt) residue” is used. Of course, the alloy to be powdered may be an alloy of other composition, for example, an alloy ratio of “Cr (chromium) 25 wt%, Ni (nickel) 10 wt%, W (tungsten) 7 wt%, Co (cobalt) residue”. These alloys can also be used. “Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) residue” “Cr (chromium) 15 wt%, Fe (iron) 8 wt%, "Ni (nickel) residue", "Cr (chromium) 21 wt%, Mo (molybdenum) 9 wt%, Ta (tantalum) 4 wt%, Ni (nickel) residue", "Cr (chromium) 19 wt%, Ni ( Alloy ratio of “nickel) 53 wt%, Mo (molybdenum) 3 wt%, (Cd + Ta) 5 wt%, Ti (titanium) 0.8 wt%, Al (aluminum) 0.6 wt%, Fe (iron) residue” An alloy of may be used. However, since the properties such as the hardness of the material are different when the alloy ratio of the alloy is different, there are some differences in the formability of the electrode and the state of the coating.

If the electrode material is hard, it becomes difficult to form a powder by pressing.
Further, when the strength of the electrode is increased by the heat treatment, it is necessary to devise such as increasing the heating temperature.
For example, an alloy with an agreed gold ratio of “Cr (chromium) 25 wt%, Ni (nickel) 10 wt%, W (tungsten) 7 wt%, Co (cobalt) balance” is relatively soft, “Mo ( An alloy having an alloy ratio of “molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, and Co residue” is a relatively hard material.
In the case of the heat treatment of the electrode, in order to give the electrode the necessary hardness, it is necessary to set the latter to an average higher by about 100 ° C. than the former.
Further, the ease of forming a thick film becomes easier as the amount of metal contained in the coating increases, as shown in the first to fourth embodiments.
As the material contained in the alloy powder that is a component of the electrode, the more the Co (cobalt), Ni (nickel), and Fe (iron) that are difficult to form carbides, the easier it is to form a dense thick film.

When tests were conducted with various alloy powders, it was found that thick films were easily formed stably when the content of the material in which the carbides in the electrode were difficult or not formed exceeded 40% by volume.
And it turned out that it is more preferable that the content of Co in the electrode exceeds 50% by volume because a thick film having a sufficient thickness can be formed.
The volume% of the material in the alloy is difficult to define, but here, the ratio of the value obtained by dividing the weight of each powder to be mixed by the density of each material is defined as volume%.
Needless to say, if the material to be mixed as an alloy has a material with a specific gravity close to that of the original material, it is almost the same as the weight%.

  Moreover, even if the material mixed as a component of the alloy other than Co (cobalt), Ni (nickel), and Fe (iron), which are difficult to form carbides, is a material that forms carbides, the relative If the material is difficult to form carbides, metal components other than Co (cobalt), Ni (nickel), and Fe (iron) are included in the coating, and Co (cobalt) and Ni (nickel) are included. ), The ratio of Fe (iron) can form at least a dense thick film.

In the case of an alloy of two elements of Cr (chromium) and Co (cobalt), it has been found that a thick film is easily formed when the Co (cobalt) content in the electrode exceeds 20% by volume. As described above, the volume percent of Co (cobalt) here is ((weight percent of Co) / (specific gravity of Co)) / (((weight percent of Cr) / (specific gravity of Cr)) + ( (Weight% of Co) / (specific gravity of Co))).
Cr (chromium) is a material that forms carbides, but is a material that hardly forms carbides as compared to an active material such as Ti. When the film components were analyzed by X-ray diffraction, XPS (X-ray Photoelectron Spectroscopy), etc., a peak indicating the presence of Cr ₃ C ₂ (chromium carbide) and data indicating the presence of Cr (chromium) were observed.
That is, in the case of Cr (chromium), although it is a material that is easily carbonized, it is less easily carbonized than a material such as Ti (titanium), and the electrode contains Cr (chromium). In this case, a part thereof becomes a carbide, and a part becomes a film with the metal Cr (chromium) as it is.
Considering the above results and the like, it is considered necessary to form a dense thick film that the ratio of the material remaining as metal in the coating is about 30% or more by volume.

As in the fourth embodiment, “Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) residue”, “Cr (chromium) 25 wt%, Ni (Nickel) 10 wt%, W (tungsten) 7 wt%, Co (cobalt) residue "," Cr (chromium) 20 wt%, Ni (nickel) 10 wt%, W (tungsten) 15 wt%, Co (cobalt) The material such as “residue” is a material that exhibits the effect of wear resistance because Cr ₂ O ₃ (chromium oxide) formed by oxidation of Cr (chromium) under high temperature environment exhibits lubricity. As in the third embodiment, it is effective for the low pressure turbine rotor blade part, the turbine stationary blade positioning part, and the like.
"Cr (chromium) 15 wt%, Fe (iron) 8 wt%, Ni (nickel) remaining", "Cr (chromium) 21 wt%, Mo (molybdenum) 9 wt%, Ta (tantalum) 4 wt% , Ni (nickel) residue ”,“ Cr (chromium) 19 wt%, Ni (nickel) 53 wt%, Mo (molybdenum) 3 wt%, (Cd + Ta) 5 wt%, Ti (titanium) 0.8 wt%, Nickel-based materials such as “Al (aluminum) 0.6 wt%, Fe (iron) residue” are materials that exhibit heat resistance, and are suitable for repairing high-pressure turbine blades and the like. The high-pressure turbine blade is made of a material such as a single crystal material or a unidirectionally solidified alloy, and there is a problem that when the heat is concentrated, it is cracked immediately. Since the method of the present invention is a method of forming a coating film by pulsed discharge, the coating film can be formed without generating heat even if a material that is easily cracked does not concentrate heat.
As a result, it is possible not only to manufacture and repair turbine parts easily and to improve the quality, but also to increase the reliability of the parts, thereby supplying a high-quality gas turbine.

Embodiment 6
FIG. 14: is sectional drawing which shows the concept of the electrode for discharge surface treatment concerning Embodiment 6 of this invention, and its manufacturing method.
In FIG. 14, the space surrounded by the upper punch 1303 of the mold, the lower punch 1304 of the mold, and the die 1305 of the mold is filled with a mixed powder obtained by mixing Co (cobalt) powder 1302 with Co alloy powder 1301. The
Then, a green compact is formed by compression molding the mixed powder.
In the discharge surface treatment, this green compact is used as a discharge electrode. The press pressure for compressing the powder was about 100 MPa, and the heating temperature was in the range of 600 ° C to 800 ° C.

The alloy ratio of the Co alloy powder 1301 is “Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) 52 wt%”. The alloy material having such an alloy ratio is powdered. Co alloy powder 1301 and Co powder 1302 both have a particle size of about 2 μm to 6 μm.
Alloys with an alloy ratio of “Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) 52 wt%” are resistant to wear in high temperature environments. It is an alloy used as a material for. This alloy exhibits the effect of wear resistance effectively since the hardness of the material and Cr ₂ O ₃ (chromium oxide) formed by oxidation of Cr (chromium) in a high temperature environment exhibit lubricity. Therefore, a film having excellent wear resistance can be formed by using an electrode containing the alloy powder.

  However, when the coating is formed by the discharge surface treatment, the electrode can be produced only from the alloy powder having the same composition as it is, but because of the hardness of the material, it is difficult to form at the time of compression molding by pressing. There are some problems, the problem is that the quality of the electrode tends to vary and the problem that it is difficult to form a dense film because Mo (molybdenum), which is easy to form carbides, is contained in a relatively large amount. is there.

When there is a problem as described above, it is possible to improve the ease of forming a thick film by further mixing Co (cobalt) powder.
An electrode is prepared only from an alloy powder having an alloy ratio of “Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) 52 wt%”. In the case where the discharge surface treatment apparatus is formed to form a film, the space ratio in the formed film is about 10%.
On the other hand, Co (cobalt) powder is added to an alloy powder having an alloy ratio of “Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) 52 wt%”. When an electrode is produced from a mixed powder mixed with about 20% by weight and a discharge surface treatment apparatus using the electrode is formed to form a film, the porosity in the film is reduced from about 3% to about 4%. be able to.
Accordingly, 20 wt% of Co (cobalt) powder is added to the alloy powder having an alloy ratio of “Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) 52 wt%”. By using an electrode made of a mixed powder mixed with about%, it is possible to form a dense thick film while having an effect of wear resistance.
As a material having such an effect, Ni or Fe can be used in addition to Co, and a plurality of these materials can be mixed.

“Mo (molybdenum) 28 wt%, Cr (chromium) 17 wt%, Si (silicon) 3 wt%, Co (cobalt) residue” is Cr ₂ O _{3 formed} by oxidation of Cr (chromium) in a high temperature environment. (Chromium oxide) is a material that exerts an effect of wear resistance because it exhibits lubricity. Like the fourth to fifth embodiments, the sliding part of the high temperature member of the turbine, the part of the low pressure turbine blade, This is effective for the positioning part of the turbine stationary blade.
In addition, since the denseness of the coating is improved by mixing Co powder, the coating strength in a low temperature range where the lubricity due to the oxides of Cr and Mo cannot be expected can be increased.
Moreover, since the coating can be made dense, not only can the quality and quality of the turbine parts be easily manufactured and repaired, but a high quality gas turbine can be supplied by increasing the reliability of the parts.

Conventional turbine parts often use methods such as thermal spraying and welding. Welding is an operation that is difficult to put into the flow production line, and is a process of performing welding work outside the line and putting the welded parts into machining on the line.
Similarly, when overlaying is performed by thermal spraying, previous and subsequent steps are required, and processing is difficult.
In the case of thermal spraying, as a pretreatment, a masking process is performed so that the thermal spray material is not applied to a place where a coating is not desired, and after the thermal spraying process, a process for adjusting the shape is necessary as in the case of welding.
All of these operations depended on manpower, and there were variations in quality.
In addition, turbine blades and compressor blades have many thin structures, and in the processing method in which heat is concentrated like welding, there is a problem that deformation, cracking, etc. occur and yield decreases.
In particular, parts made of fragile materials such as single crystal materials and unidirectionally solidified alloys were easily broken.
In the turbine component of the present invention, the coating is formed by processing performed by a machine that does not require manual labor, so the quality is stable and the cost can be reduced.
In addition, even parts made of materials that are easily broken due to intensive heat input do not break or deform, and are highly reliable parts.
A gas turbine incorporating such a high-reliability and low-cost component can greatly reduce the cost and has high reliability.

It is a figure which shows one Example of 1st invention. It is a figure which shows one Example of 1st invention. It is a figure which shows one Example of 1st invention. It is a figure which shows one Example of 1st invention. It is a figure which shows one Example of 1st invention. It is a figure which shows one Example of 1st invention. It is a figure which shows one Example of 2nd invention. It is a figure which shows one Example of 3rd invention. It is a figure which shows one Example of 3rd invention. It is a figure which shows one Example of 3rd invention. . It is a figure which shows one Example of 4th invention. It is a figure which shows one Example of 5th invention. It is a figure which shows one Example of 5th invention. . It is a figure which shows one Example of 6th invention. . It is a figure which shows the structure of a turbine component. It is a figure which shows the structure of a turbine component. It is a figure which shows the film by welding.

Explanation of symbols

  101 Cr powder, 102 Co (cobalt) powder, 103 upper punch, 104 lower punch, 105 die.

Claims (13)

A pulsed discharge is generated in the working fluid or in the air between the metal powder containing at least 40% by volume of Co, Fe, and Ni, or a green compact electrode obtained by compression molding a metal compound powder. Based on the electrode material supplied from the green compact electrode by energy, a coating containing 30% by volume or more of a metal component that is not carbide and carbide is formed on the blade tip portion or the sliding portion. Turbine parts. Co, Fe, generating pulsed discharge in the machining fluid or in the gas between the powder compression molding to configure the electrode including an alloy material 40 vol% or more of metal elements Ni, using discharge energy A turbine component characterized in that an electrode material or a coating of a material whose electrode material is changed by discharge energy is formed on a blade tip portion or a sliding portion. The alloy material includes Co as a main component, Co alloy including Cr, Ni, and W, or Co as a main component, Co alloy including Mo, Cr, and Si, Ni as a main component, and Cr and Fe. A Ni alloy, a Ni alloy containing Ni as a main component and containing Cr, Mo, Ta, and a Fe alloy containing Cr, Ni, Mo, (Cd + Ta), Ti, and Al as a main component. Item 3. The turbine component according to Item 2. 4. The turbine component according to claim 2, wherein the electrode is made of a powder obtained by mixing at least one of Co, Ni, and Fe with the alloy material powder. 5. The turbine component according to any one of claims 1 to 4, wherein a material of the turbine component is a direction control alloy such as a single crystal alloy or a unidirectionally solidified alloy. Abrasive film having Cr3C2 or TiC component is formed on the blade tip, or an abrasion-resistant film having a Cr component which is oxidized in a high temperature environment to Cr2O3 is formed on the sliding part. The gas turbine component according to claim 1. A pulsed discharge is generated in the working fluid or in the air between a metal powder containing at least 40% by volume of a metal material of Co, Fe, and Ni as an electrode material, or a green compact electrode formed by compression molding a metal compound powder. Based on the electrode material supplied from the green compact electrode by the discharge energy, a coating containing 30% by volume or more of a metal component that is not carbide and carbide is formed on the blade tip portion or the sliding portion. A gas turbine composed of turbine parts. Co as the electrode material, Fe, generating pulsed electric discharge in the machining fluid or air in between the powder compression molding to configure the electrode including an alloy material 40 vol% or more of metal elements of Ni, the A gas turbine comprising a turbine component in which an electrode material or a coating of a material whose electrode material is changed by discharge energy is formed on a blade tip portion or a sliding portion by discharge energy. The alloy material includes Co as a main component, Co alloy including Cr, Ni, and W, or Co as a main component, Co alloy including Mo, Cr, and Si, Ni as a main component, and Cr and Fe. A Ni alloy, a Ni alloy containing Ni as a main component and containing Cr, Mo, Ta, and a Fe alloy containing Cr, Ni, Mo, (Cd + Ta), Ti, and Al as a main component. Item 8. The gas turbine according to Item 7. 10. The gas turbine according to claim 8, wherein the electrode is made of a powder obtained by mixing at least one of Co, Ni, and Fe with the alloy material powder. 11. The gas turbine according to any one of claims 7 to 10, wherein a material of the turbine component is a direction control alloy such as a single crystal alloy or a unidirectionally solidified alloy. A pulsed discharge is generated in the working fluid or in the air between a metal powder containing at least 40% by volume of a metal material of Co, Fe, and Ni as an electrode material, or a green compact electrode formed by compression molding a metal compound powder. Based on the electrode material supplied from the green compact electrode by the discharge energy, a coating containing 30% by volume or more of a metal component that is not carbide and carbide is formed on the blade tip portion or the sliding portion. A method for manufacturing a turbine component, comprising: Co as the electrode material, Fe, generating pulsed discharge machining fluid or air in between the powder compression molding to configure the electrode including an alloy material 40 vol% or more of metal elements of Ni, the A method of manufacturing a turbine component, characterized in that an electrode material or a coating of a material whose electrode material is changed by discharge energy is formed on a blade tip portion or a sliding portion by discharge energy.

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