JP2012012622A - System and method for thermal spraying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for thermal spraying, which applies a heat stress mitigative heat barrier coating excellent in heat barrier performance and durability, and to provide a method for thermal spraying.SOLUTION: The thermal spraying system includes: a rotary table 5 on which a substrate is disposed; a first heater disposed on the rotary table 5 and heating a first part of the substrate; a motor 2 for rotating the rotary table 5 on which the substrate heated by the first heater is disposed; a second heater that is scanned in the direction along an axis of the rotation, and heats a second part of the substrate on the rotated rotary table 5 by plasma or flame; and a plasma thermal spraying gun 1 for forming a partially-stabilized zirconia layer in the second part heated by the second heater.

Description

  The present invention relates to a thermal spraying system and a thermal spraying method.

  Research and development aimed at improving thermal efficiency is underway in prime movers such as gas turbines and jet engines. One of the most effective means for improving thermal efficiency is to increase the operating gas temperature. For this reason, the improvement in thermal efficiency is generally in the direction of forcing the component members to a higher temperature and severe use environment.

  High-temperature components that are in direct contact with combustion gases such as moving blades, stationary blades, and combustors are being studied from two viewpoints to withstand use in high-temperature environments.

  First, the study from the first point of view is to improve the cooling characteristics to lower the temperature of the component materials. In principle, it is effective to increase the cooling gas (air) flow rate in order to improve the cooling characteristics. However, simply increasing the cooling gas flow rate decreases the combustion gas temperature, and conversely, the thermal efficiency often decreases.

Therefore, as a method of improving the cooling performance without increasing the cooling gas flow rate, a method of gradually heating more efficiently with a small cooling gas flow rate has been proposed. There are a method of increasing heat transfer between a material / cooling gas typified by film cooling and impingement cooling, and a method of increasing a contact area of material / cooling gas typified by a return flow structure of a blade cooling channel.
However, since these methods lead to complicated device structures and component structures in any case, it has been pointed out that the device control is complicated and the manufacturing cost is increased.

  The second point of study is to improve the heat-resistant temperature of the material. Already, Ni, Co or Fe-based superalloys are being developed as structural materials for high-temperature parts. In addition, high-temperature strength is further improved by unidirectional solidification and single crystal. However, in these methods, the use limit is at most 1000 ° C. in view of the melting point of the superalloy described above. Furthermore, as a method for improving heat resistance, ceramic materials having a high melting point and excellent oxidation resistance and corrosion resistance are being applied.

Although there are actually attempts to use ceramics based on SiC or Si ₃ N ₄ , they are inferior in toughness, workability, and have many drawbacks compared to metal materials. Therefore, problems remain in terms of reliability and cost for wide application as high-temperature component structural materials.

  On the other hand, there is a thermal barrier coating as a method for improving heat resistance while using a metal material having excellent toughness as a strength member (strength holding member). In this thermal barrier coating, a low thermal conductivity oxide ceramic layer (thermal barrier ceramic layer) is formed on the substrate to block heat and prevent the metal substrate from rising in temperature. There is a report that the surface temperature rise of a metal substrate can be reduced by several tens of degrees Celsius by forming a heat-shielding ceramic layer of several hundred microns (μm) (see Patent Document 1).

  Thereby, the temperature rise of the metal base material used as a strength member (strength holding member) can be suppressed, and the temperature of the gas turbine can be increased. That is, in the thermal barrier coating, qualitatively, the thicker the thermal barrier ceramic layer, the better the thermal barrier performance, and the temperature of the metal substrate can be further reduced. In addition, this thermal barrier coating reduces the heat flux from the combustion gas side to the cooling air, thereby reducing the cooling gas flow rate.

  However, there are problems in applying thermal barrier coatings widely. In particular, cracking and peeling of the coated thermal barrier ceramic layer is the biggest problem. The separation of the thermal barrier ceramic layer is due to the inherent properties of the ceramic material itself, which have low toughness, the thermal stress generated by the difference in thermal expansion between the metal substrate and the thermal barrier ceramic material, and the metal surface directly under the thermal barrier ceramic layer. This may be due to material deterioration associated with oxidation of the material.

  Once delamination occurs in the thermal barrier ceramic layer, the thermal barrier performance decreases, and the temperature of the metal substrate rises. This may cause major troubles that hinder the operation of the equipment, such as melting of the metal base material, creep of the metal base material, and fatigue failure.

  On the other hand, various studies have been made for the purpose of reducing the peeling of the thermal barrier coating. A typical thermal barrier coating is a two-layer structure in which an MCrAlY alloy layer and an oxide ceramic layer such as a zirconia ceramic of low thermal conductivity ceramic are formed on a metal substrate. This MCrAlY alloy layer is intended to improve the adhesion between the metal substrate and the thermal barrier ceramic layer and to prevent corrosion and oxidation of the metal substrate, and is often formed by a thermal spraying method.

  According to the thermal spraying method, there is an advantage that the kind of material can be arbitrarily selected regardless of whether it is a metal or a ceramic. However, when the MCrAlY alloy is coated in the atmosphere using a plasma spraying method having a high-temperature heat source, for example, (1 There were drawbacks such as :) porousness, (2) poor adhesion to metal substrates, and (3) poor corrosion resistance and oxidation resistance. With regard to this point, these drawbacks have been greatly improved in recent years by a plasma spraying method (low pressure plasma spraying method) in a reduced pressure inert gas atmosphere substantially free of air.

  In addition, for the thermal barrier ceramic layer, in order to stabilize the phase of zirconia and improve the thermal cycle characteristics, the types and amounts of additives for stabilization are examined, and the layer structure is partly columnar. An electron beam physical vapor deposition method (EB-PVD method) characterized by the structure has been studied. In particular, when a sudden temperature change occurs in the thermal barrier ceramic layer, such as when starting and stopping, cracking and peeling may occur due to the low toughness of the thermal barrier ceramic layer. This is likely to occur when a thick thermal barrier ceramic layer is formed.

  As a solution to this, it is possible to reduce the thermal conductivity by increasing the porosity of the heat-shielding ceramic layer from 5 to 60%, and to reduce cracking and peeling (see Patent Document 2). In addition, cracks generated in the thermal barrier ceramic layer (partially stabilized zirconia layer) can absorb energy through pores, so that both toughness and strength can be improved.

  Furthermore, the outermost surface of the thermal barrier ceramic layer is a porous layer having a porosity of 5 to 60%, and the partially stabilized zirconia layer whose porosity is closer to the interface with the MCrAlY alloy layer than the outermost surface side of the thermal barrier ceramic layer. And That is, in the vicinity of the interface with the MCrAlY alloy layer having a large thermal stress during steady operation, a high-strength partially stabilized zirconia layer having a denser and lower porosity and a high-strength partially stabilized zirconia layer having a lower porosity. It becomes. As a result, cracking and peeling can be reduced.

  However, since the porosity of the outermost surface of the thermal barrier ceramic layer is high and the dense thermal barrier ceramic layer at the interface with the MCrAlY alloy layer has many pores on the outermost surface of the thermal barrier ceramic layer, sludge and corrosion products contained in the fuel , Erosion due to the solid of the corrosive oxide flowing out from the piping system causes thinning due to weak interparticle bonding force.

  In addition, by making the pores of the partially stabilized zirconia film near the interface between the MCrAlY alloy layer interface and the thermal barrier ceramic layer dense, thermal stress due to the difference in thermal expansion coefficient is likely to occur even if the adhesion is increased. As a result, the peel resistance decreases.

  As a solution, a technique described in Patent Document 3 has been proposed. In this technique, the oxide ceramic layer has pores provided so that the porosity gradually decreases from the metal intermediate layer side toward the surface side of the oxide ceramic layer, There is a crack in the thickness direction of the oxide ceramic layer extending from the interface to the surface of the oxide ceramic layer.

  As a manufacturing method of the thermal barrier coating member, the manufacturing method in which the porosity of the partially stabilized zirconia layer is inclined from 15% to 5% is that the MCrAlY alloy layer is formed on the metal substrate, and then the partially stabilized zirconia powder is used. It is formed by atmospheric plasma spraying.

  At this time, the plasma flame (flame) generated from the atmospheric plasma spray gun to be used is heated by preheating to a temperature region of 650 ° C. or higher where a vertical crack can be generated, and spraying of the partially stabilized zirconia powder is started. By preheating and heating to 650 ° C or higher with a plasma flame (flame) generated from an atmospheric plasma spray gun, and without lowering the temperature to 650 ° C or lower during the formation of the partially stabilized zirconia layer, A vertical crack is generated in the partially stabilized zirconia layer by quenching with a cooling method of blowing compressed air or the like.

  If the temperature during preheating, heating, or thermal spraying is 650 ° C or less, a transverse crack is generated at the same time as the longitudinal crack, and the peel life is reduced. This transverse crack propagates in a layer of a partially stabilized zirconia film, and it is difficult to absorb thermal stress due to delamination and rapid temperature difference between layers, resulting in a decrease in delamination life.

Thermal spraying is basically operated by skilled workers, but temperature control during spraying is extremely difficult, and it is necessary to control temperature quantitatively. In particular, in order to introduce a vertical crack, it is necessary to maintain the previous temperature, and therefore it is necessary to manage it quantitatively by measuring the temperature.
In this case, it is most important to control the temperature by attaching a thermocouple to the metal substrate and measuring the temperature during construction. Infrared radiation thermometers are also effective, but the use of thermocouples is effective because of the influence of the emissivity of the plasma flame and the object being measured.

JP-A-62-211387 Japanese Patent Application No. 9-231042 JP 2006-144061 A

  However, these methods, for example, in the case of a moving blade, are preheated and sprayed only by a plasma flame (flame) generated from an atmospheric plasma spray gun, so it is difficult to heat the moving blade to a high temperature (650 ° C. or higher) during preheating. In addition, since the plasma flame (flame) generated from the atmospheric plasma spray gun does not always hit the blade during spraying, the blade temperature during spraying also drops to 650 ° C. or less.

As a result, when the temperature during preheating, heating, or thermal spraying is 650 ° C. or less, a transverse crack is generated simultaneously with the longitudinal crack, and the peel life is reduced. This transverse crack propagates in a layer of a partially stabilized zirconia film, and it is difficult to absorb thermal stress due to delamination and rapid temperature difference between layers, resulting in a decrease in delamination life.
As described above, none of the effects can be obtained, and there are still demands for improvement of the peeling life, thermal stress relaxation, and thermal barrier performance improvement by improving the heating method.

  The present invention has been made in view of such circumstances, and is intended for high-temperature parts used in high-temperature oxidative corrosion environments such as gas turbines and jet engines. It is an object of the present invention to provide a thermal spraying system and a thermal spraying method for applying a coating.

  A thermal spraying system according to an aspect of the present invention includes a rotary table on which a base material is disposed, a first heating unit that is disposed on the rotary table and heats a first portion of the base material, and the first A motor for rotating a rotary table on which a base material heated by heating means is disposed, and a second portion of the base material on the rotary table scanned and rotated in the direction along the axis of rotation. A second heating means for heating with plasma or flame; and a plasma spray gun for forming a partially stabilized zirconia layer on the second portion heated by the second heating means.

  According to the present invention, it is possible to provide a thermal spraying system and a thermal spraying method for applying a thermal stress relaxation thermal barrier coating excellent in thermal barrier performance and durability.

It is a mimetic diagram showing a thermal spraying system concerning one embodiment of the present invention. It is a figure which shows an example of the wiring path | route from the heater controller 13 of a stationary side to the heater 6 of a rotation side. It is a figure which shows an example of the wiring path | route to the thermocouple 12 for measuring the temperature of the rotor blade 8 which is to-be-executed goods (base | substrate), and the temperature of the heater 6. FIG. It is a figure which shows the measurement state which measured the state which is heating the moving blade 8 of a to-be-executed product with the thermal spray gun 1 with the infrared thermography camera. It is a figure which shows the motion of the thermal spray gun 1 and the moving blade 8 in the case of heating the moving blade 8 by the rotation method. It is a figure which shows the motion of the thermal spray gun 1 and the moving blade 8 in the case of heating the moving blade 8 by a sequential (index) method. It is a figure which shows the measurement state which measured the temperature state of the thermal spray gun 1 at the time of heating the moving blade 8 by the rotation method, and the moving blade 8 with the infrared thermography camera 14. FIG. It is a figure which shows the measurement state measured with the thermal imaging camera 14 which showed the thermal spray gun 1 at the time of heating the blade 8 by the sequential (index) method, and the temperature state of the blade 8. FIG. It is a schematic diagram showing the thermal spraying system which concerns on other embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic diagram showing a thermal spraying system according to a first embodiment of the present invention.
The thermal spray system consists of an MCrAlY alloy (M: Ni, Co, Fe, or an alloy combining these elements) layer and a partially stabilized zirconia layer (thermal stress relaxation and heat shield) on the moving blade 8 (worked product, metal substrate). Coating coating).

  Thermal spraying system consists of spray gun 1, rotary motor 2, basic table 3, rotary table shaft 4, rotary table 5, heater 6, masking 7, moving blade 8, protective lid 9, heater slip ring 10, temperature measurement slip The ring 11, the thermocouple 12, the heater controller 13, the infrared thermography camera 14, the thermal spray robot 15, the robot control device 16, the infrared thermography controller 17, and the temperature measurement device 18 are configured.

  The thermal spray gun 1 has a plasma gun that generates plasma. By supplying the powder material to plasma generated from the plasma gun, the powder material is melted and scattered, and spraying (film formation) on the rotor blade 8 is performed.

The thermal spray gun 1 can be used not only for film formation (spraying) on the moving blade 8 but also for heating the moving blade 8. Plasma can obtain a flame flame of 1 to 30,000 degrees and has a large heat capacity during heating. As will be described later, the moving blade 8 is heated by the spray gun 1 and the heater 6.
As the spray gun 1, a plasma spray gun that generates plasma with a mixed gas of hydrogen gas and nitrogen gas, or an atmospheric plasma spray gun that generates plasma in the atmosphere can be used.

  The thermal spray gun 1 (plasma gun) functions as a second heating means (plasma / flame heating means) for heating a second part (for example, the upper part) of the substrate (for example, the moving blade 8) with plasma or flame. As will be described later, the spray gun 1 is scanned by the spray robot 15 in a direction (for example, a Dz direction (up and down direction) described later) along the axis of rotation (the rotary table axis 4).

  Here, instead of the plasma gun, a gas burner or the like can be used as a plasma / flame heating means. Using a combustion flame of LPG (liquefied petroleum gas, propane gas), hydrogen gas, or oxygen acetylene gas (mixed gas of oxygen and acetylene), film formation (spraying) on the blade 8 and heating of the blade 8 are performed. Can be executed. Further, film formation (spraying) on the moving blade 8 and heating of the moving blade 8 may be performed using air heated to a high temperature and an inert gas heated to a high temperature.

  The thermal spray gun 1 is attached to the tip of the thermal spray robot 15. When the thermal spraying robot 15 is driven by program control of the robot controller 16, the thermal spray gun 1 is scanned on the moving blade 8, and the moving blade 8 can be heated and sprayed over a wide range.

The moving blade 8 is installed on the rotary table 5 that is rotated by the motor 2 for rotation. That is, the moving blade 8 is rotated by the rotating motor 2. The rotary motor 2 has the function of rotating the rotary table shaft 4, the rotary table 5, and the one installed on the rotary table 5 (heater 6, masking 7, moving blade 8, protective cover 9). Rotation, sequential rotation, and continuous rotation are possible.
When the spray gun 1 heats or sprays the blade 8, the blade 8 is driven by the rotation motor 2 by the rotation method or the sequential method. Details of the rotation method and the sequential method will be described later.

  A heater 6 is attached and fixed to the rotary table 5, and a moving blade 8 and a protective lid 9 are further installed. The turntable 5 is preferably made of a metal material. Here, by using a non-ferrous metal material, particularly an aluminum alloy material, it is possible to reduce the weight load on the rotation motor 2 during rotation.

  The rotary table shaft 4 transmits the driving force of the rotation motor 2 and fixes the heater slip ring 10 and the temperature measurement slip ring 11 so that the electric power of the heater 6 and the electromotive force of the thermocouple 12 are transmitted from the rotation side. Supply and transmit from the stationary side or stationary side to the rotating side.

The heater 6 is a device that uniformly heats the moving blade 8 according to a command from the heater controller 13. The heater 6 is disposed on the rotary table and functions as a first heating unit that heats a first portion (for example, the lower portion) of the base (for example, the moving blade 8).
In this thermal spraying system, the moving blade 8 is heated to a high temperature by plasma / flame heating means such as a plasma gun (spraying gun 1), and then a thermal stress relaxation coating is formed on the surface of the moving blade 8 by thermal spraying. However, the thermal spray gun 1 alone does not have sufficient heating ability to form a thermal stress relaxation coating. For this reason, the moving blade 8 is always supplementarily heated by the heater 6 to compensate for the thermal energy that is insufficient when the thermal spray gun 1 is heated.

As the heater 6, any one type or a combination of two or more types of an electric furnace with a protective lid 9, a belt-shaped winding heater, an infrared heating heater, and a high-frequency induction heating heater can be used.
Since the electric furnace can be heated with a large capacity, the moving blade 8 can be heated in a short time and uniformly. In addition, when the moving blade 8 is heated in combination, the heating time can be shortened. For example, the heating effect is further increased by combining and heating the moving blade 8 with an infrared heater or a gas burner flame.

  The heater controller 13 controls, adjusts, and commands the amount of power supplied to the heater 6 based on the result of measuring the temperature of the heater 6 with the thermocouple 12. The heater controller 13 is a temperature measuring device that is electrically connected to the control unit that controls the first heating means and the fourth slider so that the first portion of the base body is 650 ° C. or higher. Function.

  The protective lid 9 has a function of not releasing the heated heat to the outside. The protective lid 9 is removed when the spray gun 1 is heated and when a coating is formed on the surface of the moving blade 8 by spraying (at the time of spraying). The protective lid 9 is lined with a heat-resistant heat insulating material and has a structure that does not allow the heated heat of the moving blade 8 to escape to the outside. Further, by incorporating a heater inside, the subject moving blade 8 can be heated to a predetermined temperature in a short time, and the manufacturing time of the thermal stress relaxation coating can be shortened.

  The masking member 7 is a masking member for preventing the film from adhering to unnecessary parts during thermal spraying, and has the effect of simplifying the surface finish of the moving blade 8 after thermal spraying of the thermal stress relaxation coating coating. The manufacturing time of the stress relaxation coating can be shortened.

The infrared thermography camera 14 measures the surface temperature of the moving blade 8 which is an article to be executed (substrate) at the time of heating and spraying, transmits the temperature to the infrared thermography controller 17, and determines the end of heating based on the displayed heating temperature. Provide information.
The infrared thermography controller 17 continuously measures the infrared information temperature during thermal spraying of the moving blade 8 which is a product to be measured, measured by the infrared thermography camera 14, in real time, and records the temperature history.

  The heater slip ring 10 (first slip ring) and the temperature measurement slip ring 11 have a rotating contact (terminal) and a stationary contact (terminal), and an electrical signal is generated by rotating contact between carbon brushes or contact materials. Or transmit power. The heater slip ring 10 supplies electric power necessary for the heater 6 such as 100 V to 250 V from the stationary side to the rotating side, and supplies the electric power transmitted to the rotating side via the rotary table shaft 4 to the heater 6. The temperature measuring slip ring 11 (second slip ring) measures the temperature of the heater 6 with the thermocouple 12 and transmits the temperature to the stationary heater controller 13 and the temperature measuring device 18.

  FIG. 2 is a diagram illustrating an example of a power supply state from the stationary heater controller 13 to the rotating heater 6.

  Power to the rotation side heater 6 is supplied to the rotation side sliding terminal 10d as follows. That is, the anode-cathode power cable 13b is connected from the power supply output section 13a of the stationary heater controller 13 to the stationary sliding terminal 10a (first slider) installed in the heater slip ring 10, The stationary slider 10b and the rotary slider 10c (second slider) installed in the heater slip ring 10 and fixed to the rotary table shaft 4 are in sliding contact.

  The energized power is connected to the power input portion 13d of the heater 6 fixed to the rotary table 5 by a power cable 13c passing through the center hole 4a of the rotary table shaft 4, and energized to the resistor 13e. The resistor 13e generates heat from the energized power source and heats the moving blade 8.

  The turntable 5 rotates at a high speed of, for example, 260 rotations / minute and is supplied with a power supply voltage of 100 V or more. In other words, stationary and rotating terminals (contacts) 10a and 10d are necessary for transmission of electric signals such as electric power to the rotating body, and conventionally, a heater 6 such as an electric furnace is on the rotating side. It was rarely used. However, by using the heater slip ring 10 capable of supplying a power voltage of 100 V or more, it is possible to constantly heat the moving blade 8 which is a product to be enforced while rotating.

FIG. 3 is a diagram showing an example of a wiring route to the thermocouple 12 for measuring the temperature of the moving blade 8 and the temperature of the heater 6 which are the articles to be executed (base).
The thermocouple 12 connected to the temperature measuring device 18 is connected to the stationary side slider 12b (fourth slider) through the stationary side connection terminal 12a of the temperature measuring slip ring 11. Next, the thermocouple 12 attached to a part of the moving blade 8 is passed through the center hole 4a of the rotary table shaft 4 connected to the rotary table 5, and the rotary side slider 12c (third slide) of the slip ring 11 for temperature measurement. Connect to the moving child). The temperature signal of the moving blade 8 is transmitted to the stationary slider 12b through these connection paths, and is transmitted to the temperature measuring device 18 through the stationary connection terminal 12a. The transmitted temperature signal is recorded by the temperature measuring device 18.

  The thermocouple 12 is also installed inside the heater 6, and is similarly connected to the rotary slider 12 c of the temperature measuring slip ring 11 through the center hole 4 a of the rotary table shaft 4. The temperature signal of the heater 6 is transmitted to the stationary slider 12b through these connection paths, and is transmitted to the temperature measuring device 18 and the heater controller 13 through the stationary connection terminal 12a. The transmitted temperature signal of the heater 6 is analyzed by the heater controller 13 and feedback control to the heater 6 is performed.

(The procedure of thermal spraying by thermal spraying system)
The thermal stress relaxation coating procedure using the thermal spray system is described below.
(1) Formation of MCrAlY Alloy Layer An MCrAlY alloy layer (M: Ni, Co, Fe or an alloy combining these elements) layer is formed on the rotor blade 8. The MCrAlY alloy layer can be formed on the moving blade 8 using any one of a low pressure plasma spraying method, a composite plating method, a high speed flame spraying method, and an ultra high speed flame spraying method.

(2) Preheating Prior to the formation of the partially stabilized zirconia layer, the rotor blade 8 on which the MCrAlY alloy layer is formed is preheated. For example, the moving blade 8 is heated by a plasma flame (flame) generated from an atmospheric plasma spray gun used for spraying. Details of this will be described later.

(3) Formation of Partially Stabilized Zirconia Layer After the MCrAlY alloy layer is formed on the rotor blade 8, a partially stabilized zirconia layer can be formed using an atmospheric plasma spraying method or the like. In the atmospheric plasma spraying method, a partially stabilized zirconia layer having a wide range of functions can be formed by using a gun capable of controlling the output of plasma gun output from 20 Kw to 180 Kw. A partially stabilized zirconia layer is formed by spraying partially stabilized zirconia powder with atmospheric plasma.

  After preheating the rotor blade 8, the partially stabilized zirconia powder is supplied into the plasma flame (flame) from the atmospheric plasma spray gun, and spraying of the partially stabilized zirconia is started. At this time, it is preferable that the temperature of the moving blade 8 is 800 ° C. or less for the reason described later.

  Here, in order to incline the porosity of the partially stabilized zirconia layer, the particle diameter of the partially stabilized zirconia powder used for atmospheric plasma spraying is switched over time. That is, a plurality of partially stabilized zirconia ceramic powders having different particle diameters are prepared, and the powder used for thermal spraying is switched over time.

The average particle diameter of ordinary partially stabilized zirconia ceramic powder is determined, and several types of partially stabilized zirconia ceramic powder can be prepared. For example, thermal spray powder having an average particle diameter of 45 to 75 microns can be used near the interface between the MCrAlY alloy layer and the partially stabilized zirconia layer, and an average particle diameter of 20 to 40 microns can be used for the surface layer of the partially stabilized zirconia layer. .
In this case, prepare two or more ports of the powder supply device of the thermal spraying device, and after completing the construction to the target thickness of each layer, switch the ports one after another to supply partially stabilized zirconia sprayed powder with different particle sizes, A partially stabilized zirconia layer having a graded porosity is formed.

(4) Cooling After the thermal spraying, the moving blade 8 on which the partially stabilized zirconia layer is formed is cooled. For example, when the moving blade 8 is rapidly cooled by blowing compressed air or the like, a crack in the layer direction (longitudinal direction) is generated in the partially stabilized zirconia layer. The cooling rate is preferably 30 to 100 ° C./min, and more preferably 30 to 60 ° C./min. The cooling method is not limited to air cooling.

(5) Heat treatment After the formation of the partially stabilized zirconia layer as described above, a heat treatment using a solution treatment temperature or an aging treatment temperature of the rotor blade 8 is performed. Thereby, the adhesion between the MCrAlY alloy layer and the rotor blade 8 is improved by diffusion. In addition, a vertical crack is added in the partially stabilized zirconia layer by quenching with compressed air after this heat treatment. In other words, the occurrence of transverse cracks can be reduced and many vertical cracks can be introduced.

(Details of preheating)
Details of preheating will be described below.
The temperature during thermal spraying is preferably in the range of 750 ° C. or higher and 800 ° C. or lower. For this reason, it is preferable that the temperature at the time of preheating shall be 750 degreeC or more. If the temperature during thermal spraying is 750 ° C. or less, there is a possibility that a transverse crack will be generated simultaneously with a longitudinal crack, resulting in a decrease in the peel life. This lateral crack propagates in the partially stabilized zirconia layer, and peeling between the MCrAlY alloy layer and the partially stabilized zirconia layer is likely to occur.

  As described above, in order to introduce longitudinal cracks, it is preferable to set the temperature during thermal spraying to a range of 750 ° C. or higher and 800 ° C. or lower. In this case, it is important to control the temperature by attaching the thermocouple 12 to the rotor blade 8 and measuring the temperature during construction. Although an infrared radiation thermometer is effective as it is, the use of a thermocouple 12 is preferable because the emissivity of the plasma flame and the object to be measured is affected.

FIG. 4 is a diagram showing an actual measurement state in which a state in which the moving blade 8 of the article to be executed is heated by the thermal spray gun 1 is measured by the infrared thermography camera 14.
It can be seen that the blade 8 is uniformly heated to a high temperature by the spray gun 1. The heater 6 contributes to uniform heating of the moving blade 8.

Specifically, the moving blade 8 is heated by the following procedures (1) and (2).
(1) Heating of the moving blade 8 only by the heater 6 The moving blade 8 is heated by the heater 6 (for example, an electric furnace). The lower part of the moving blade 8 is heated. At this time, it is preferable that the rotor blade 8 is covered with the protective lid 9 and the rotor blade 8 is heated as uniformly as possible. In addition, it is more preferable that the entire rotor blade 8 is heated by a heater built in the protective lid 9.

(2) Heating of the moving blade 8 by the heater 6 and the spray gun 1 The moving blade 8 is heated by the heater 6 and the spray gun 1. The lower part of the moving blade 8 is heated by the heater 6, and the upper part (portion not covered by the heater 6) of the moving blade 8 is heated by the spray gun 1 (plasma gun). In the procedure (1), when the moving blade 8 is covered with the protective cover 9, the protective cover 9 is removed, and the moving blade 8 is rotated by the rotating motor 2 (rotation method).

In the rotation method, the following a) to d) are performed in parallel.
a) Heating of the lower part of the moving blade 8 by the heater 6 b) Heating of the upper part of the moving blade 8 by the spray gun 1 c) Rotation of the moving blade 8 by the rotating motor 2 d) Movement of the spray gun 1 by the spraying robot 15

  By combining the rotation of the moving blade 8 and the movement of the spray gun 1, the plasma from the spray gun 1 is uniformly irradiated on the entire upper portion of the moving blade 8. As a result, coupled with the heating of the lower portion of the moving blade 8 by the heater 6, the upper portion of the moving blade 8 is kept at a uniform high temperature. The plasma output from the spray gun 1 is set to 500 kW or more, for example. Further, the heater controller 13 controls the heating by the heater 6 so that the temperature of the lower part of the moving blade 8 becomes, for example, 650 ° C. or more.

  FIG. 5 is a diagram showing the movement of the thermal spray gun 1 and the moving blade 8 when the moving blade 8 is heated by the rotation method. The rotor blade 8 is rotated by the rotary table shaft 4 (the rotation axis Sz in the Z-axis direction). Further, the spray gun 1 is repeatedly moved in a direction along the rotation axis Sz (for example, a Dz direction (vertical direction) parallel to the Z axis). That is, the movement from top to bottom and from bottom to top is repeated (repeated movement in one axis direction).

  At this time, the moving blade 8 can continue to rotate in the same direction. For example, it can continuously rotate left or right. Further, the rotating direction of the moving blade 8 may be changed. For example, continuous left rotation for a certain time and continuous right rotation for a certain time may be repeated. In this case, it can be considered that the rotation of the rotor blade 8 stops at the moment when the rotation direction changes, but such a momentary or temporary stoppage of rotation is allowed.

  Further, as shown in FIG. 5, in addition to the repetitive movement in the Dz direction, repetitive movement in the Dy direction parallel to the Y direction may be performed (repetitive movement in the biaxial direction). The uniformity of temperature at the moving blade 8 can be further improved. In this case, the repetition period Ty in the Dy direction can be made smaller than the repetition period Tz in the Dz direction. In this way, when viewed on the YZ plane, the trajectory of the spray gun 1 repeats zigzag movement in the Z-axis direction (vertical direction). That is, the width of the plasma from the spray gun 1 substantially expands in the Y direction.

  Here, the movement of the spray gun 1 may not be linear. For example, the spray gun 1 may be rotated about the Dz direction as a rotation axis. In this case, the tip of the spray gun 1 moves in an arc shape.

FIG. 6 is a diagram showing the movement of the thermal spray gun 1 and the moving blade 8 when the moving blade 8 is heated by the sequential (index) method.
In the sequential (index) method, the rotor blades 8 are rotated sequentially. That is, the rotating blade 8 is repeatedly rotated (for example, a fraction of a rotation) and stopped. The rotation of the moving blade 8 by the rotating motor 2 and the movement of the spray gun 1 by the spray robot 15 are not basically performed simultaneously. That is, the moving blade 8 rotates stepwise, and the spray gun 1 moves when the rotation stops. For example, movement in the Dx, Dy, and Dz directions and rotation on the rotation axis in the Dz direction.

  If the movement of the spray gun 1 is started before the rotation of the moving blade 8 is stopped, the rotation of the moving blade 8 and the movement of the spray gun 1 are performed simultaneously or temporarily. However, this is considered to belong to the category of the sequential method.

  Considering such a limit case, the rotation method and the sequential method can be classified according to the ratio of time during which the rotation of the moving blade 8 and the movement of the spray gun 1 are performed simultaneously. For example, if the ratio R of the time during which the rotation of the moving blade 8 and the movement of the spray gun 1 are simultaneously performed with respect to the total time during which the moving blade 8 is heated by the spray gun 1 is 80% or more, the rotation method is used. If the ratio R is 20% or less, it belongs to the sequential method, and if the ratio R is greater than 20% and less than 80%, it is determined that the intermediate method, that is, neither the rotation method nor the sequential method. it can. However, in the rotation method, it is preferable that the ratio R is large. For example, it is more preferable to increase the ratio R as 90% or more, 95% or more, or 99% or more.

  In FIG. 5, as described above, for example, the moving blade 8 is rotated by the rotary table 5, and one direction or forward rotation and reverse rotation are repeated continuously, and the spray gun 1 is moved continuously in the left-right direction and the up-down direction. Let As a result, since the flame of the thermal spray gun 1 is in a state of heating the entire rotor blade 8, the heating temperature continues to rise, the temperature of the rotor blade 8 once heated is small, and heating is completed in a short time. .

  On the other hand, in FIG. 6, as described above, the frame of the thermal spray gun 1 heats only a part of the moving blade 8 while the moving blade 8 stops sequentially. As a result, the temperature of the moving blade 8 at the portion where the back surface of the moving blade 8 or the frame of the spray gun 1 is not hit decreases. For this reason, since the temperature of the moving blade 8 once lowered is heated again and the temperature of the moving blade 8 is raised, a long time is required for the heating time.

  Basically, the flame flame of the spray gun 1 blows the moving blade 8 during heating, and either the front or back surface of the moving blade 8 is hit. When the surface is hit by the spray gun 1, the back surface is the spray gun. Since the flame of No. 1 is not hit, the temperature drops. Therefore, if the flame flame of the heating is always applied to the moving blade 8 at the time of heating or spraying, the temperature drop of the moving blade 8 is almost eliminated.

  FIG. 7 is a view showing a thermal image obtained by measuring the temperature state of the thermal spray gun 1 and the moving blade 8 with the infrared thermography camera 14 when the moving blade 8 is heated by the rotation method.

  FIG. 8 is a view showing a thermal image measured by the infrared thermography camera 14 showing the temperature state of the spray gun 1 and the moving blade 8 when the moving blade 8 is heated by the sequential (index) method.

The temperature of the moving blade 8 when the moving blade 8 is heated by the spraying gun 1 by the rotation method is lower than the moving blade 8 temperature when the moving blade 8 is heated by the spraying gun 1 by the sequential method. As shown in FIG. 7, in the rotation method, the high temperature region A11 is wide and the low temperature region A12 is narrow. On the other hand, as shown in FIG. 8, in the sequential method, the high temperature region A21 is narrow and the low temperature region A22 is wide.
As described above, the rotating method irradiates the entire moving blade 8 with the flame from the spray gun 1, and has the effects of shortening the heating time and increasing the heating temperature compared with the sequential method.

Further, the longer heating time means that a large amount of combustion gas for generating the plasma flame is consumed, and the amount of CO ₂ emission is also increased.
That is, heating the moving blade 8 by the rotation method of the present invention has a great effect of reducing CO ₂ emission.

Table 1 shows the results of heating by the sequential method and the rotation method. In the sequential method, the surface of the moving blade 8 was moved along the shape of the moving blade 8 while sequentially moving the spraying gun in the vertical and horizontal directions while sequentially stopping the moving blade 8 which is the target product. In the rotation method, the rotating blade 5 was rotated on the rotary table 5 to repeat one direction or forward rotation and reverse rotation continuously, and the spray gun 1 was moved continuously in the left-right direction and the up-down direction. Here, the conditions of plasma output 70 kW, distance 90 mm between the moving blade 8 and the spray gun 1, the moving pitch of the spray gun 1, and the moving speed of the spray gun 1 of 500 mm / second were used.
As shown in Table 1, the rotation method and the sequential method (index) differ in heating time by about three times, and the rotation method can be completed in about 1/3.

(Other embodiments)
FIG. 9 is a schematic diagram showing a thermal spraying system according to another embodiment. Here, the moving blade 8 is heated by the high-frequency induction heating coil 19 and the high-frequency transmitter 20, and plasma spraying is started by the spray gun 1 at a predetermined temperature. That is, a high frequency induction heating coil 19 is used in place of the heater 6.

  Although the heating time of the moving blade 8 by plasma spraying varies depending on the output of the spray gun 1, it can be heated to 750 ° C. in about 10 to 20 minutes when the output of the spray gun 1 is 80 kW.

On the other hand, high-frequency induction heating can be heated to 750 ° C. in a time of 5 to 10 minutes, so that it has a great effect on shortening the heating time and an effect on reducing CO ₂ emission.

  When a plasma flame is generated, a plasma combustion flame flame is generated using nitrogen gas or argon gas as a plasma combustion gas, so that the amount of CO2 generated during combustion becomes enormous.

On the other hand, a heating method that does not generate a combustion flame electrically is excellent as a technology with a low environmental load. In the future, it will contribute to CO ₂ reduction.

  In the above embodiment, a thermal stress relaxation thermal barrier coating formed by forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy thereof) and a partially stabilized zirconia layer on a metal substrate can be formed. .

  In the above-described embodiment, the spray gun 1, the rotation motor 2, the base table 3, the rotation table shaft 4, the rotation table 5, the heater 6, the masking 7, the moving blade 8, the protective lid 9, the heater slip ring 10, and the temperature measurement A heating system (spraying system) is configured by any one or a combination of the slip ring 11, the thermocouple 12, the heater controller 13, the infrared thermography camera 14, the thermal spray robot 15, the robot control device 16, the infrared thermography controller 17, the temperature measurement device 18. Is done.

  The moving blade 8 (the article to be processed, the substrate) can be heated by the first heating means (heater 6 or the like) and the second heating means (plasma gun or the like).

(1) As the heater 6 as the first heating means, any one or a combination of two or more of an electric furnace, a belt-like winding heater, an infrared heating heater, and a high frequency induction heating heater can be used.
(2) The high-frequency induction heater may be wound around the article to be enforced in a coil shape without contact.

(3) As the second heating means, the spray gun 1 as a plasma gun is used, and the moving blade 8 (product to be processed, base) can be heated with the plasma output being 50 kw or more.
(4) As the second heating means, LPG gas combustion flame, oxygen and acetylene gas mixed combustion flame, air heated to high temperature, inert gas heated to high temperature, or a combination of two or more types Can be used.
(5) The furnace temperature of the electric furnace can be automatically controlled and heated to 650 ° C. or higher.

(6) The product to be executed (the moving blade 8) is fixed to the rotary table 5 for rotating, and the heater 6 is also fixed to the rotary table and can be rotated together with the product to be executed.

(7) To supply power to the heater 6, the heater slip ring 10 is attached to the rotary table 5, and the power cable from the power input portion of the heater 6 is attached to the rotation side sliding terminal of the heater slip ring 10. Power can be supplied from the heater controller 13 outside the stationary side via the contact of the contact portion between the sliding side and the stationary side sliding terminal.
(8) When heating a product to be processed, a thermocouple 12 is attached to a part of the product to be processed, a temperature measurement slip ring 11 is attached to the rotary table 5, and a cable terminal of the thermocouple 12 is connected to the temperature measurement slip ring. It is possible to send a signal to the stationary temperature measuring device 18 through the contact point of the contact portion between the sliding side and the stationary side sliding terminal.

As a result, pre-heating time of the enforcement products, shorten the heating time, there is a very large effect on the emissions of CO _2, can provide a method for manufacturing environment friendly thermal stress relieving thermal barrier coating covering.

  In addition, the heating temperature of the workpieces is high and evenly heated, and there is no temperature drop during spraying. This prevents precracking, lateral cracking that occurs when the temperature during heating and spraying is 650 ° C or less, and prevents the peeling life and shielding. The thermal performance can be improved, and a thermal stress relaxation thermal barrier coating member suitable as a high-temperature component used in a high-temperature oxidative corrosion atmosphere such as a gas turbine or a jet engine, and a method for manufacturing the thermal stress relaxation thermal barrier coating member can be provided.

DESCRIPTION OF SYMBOLS 1 ... Spray gun, 2 ... Motor for rotation, 3 ... Base table, 4 ... Rotary table axis | shaft, 4a ... Center hole, 5 ... Rotary table, 6 ... Heater, 7 ... Masking, 8 ... Rotor blade, 9 ... Protective lid, DESCRIPTION OF SYMBOLS 10 ... Heater slip ring, 10a ... Stationary side sliding terminal, 10b ... Stationary side slider, 10c ... Rotation side slider, 10d ... Rotation side sliding terminal, 11 ... Temperature measurement slip ring, 12 ... Thermoelectric Pair, 12a ... stationary side connection terminal, 12b ... stationary side slider, 12c ... rotating side slider, 13 ... heater controller, 13a ... power output unit, 13b ... power cable, 13c ... power cable, 13d ... power input , 13e ... resistor, 14 ... infrared thermography camera, 15 ... spraying robot, 16 ... robot control device, 17 ... infrared thermography controller, 18 ... temperature measuring device, 19 High-frequency induction heating coil, 20 ... RF transmitter

Claims (8)

A turntable on which the substrate is placed;
A first heating means disposed on the turntable for heating a first portion of the base;
A motor for rotating a turntable on which a substrate heated by the first heating means is disposed;
Second heating means that scans in a direction along the axis of rotation and heats a second portion of the substrate on the rotating rotary table by plasma or flame;
A plasma spray gun for forming a partially stabilized zirconia layer on the second portion heated by the second heating means;
A thermal spraying system comprising: The thermal spraying system according to claim 1, wherein the second heating means is the plasma spray gun. The thermal spray system according to claim 2, wherein the plasma spray gun generates plasma by a mixed gas of hydrogen gas and nitrogen gas. The first heating means is any one of an electric furnace, a belt-like winding heater, an infrared heating heater, a high-frequency induction heating heater, or a combination of two or more.
The thermal spraying system according to any one of claims 1 to 3. The thermal spraying system according to any one of claims 1 to 4, further comprising a control unit that controls the first heating unit so that the first portion of the substrate has a temperature of 650 ° C or higher. A first slider electrically connected to the power source, and a second slider that is rotatably contacted with the first slider and is electrically connected to the first heating means The thermal spraying system according to any one of claims 1 to 5, further comprising a first slip ring attached to the rotary table. A thermocouple attached to the substrate;
A third slider that is electrically connected to the thermocouple; and a fourth slider that rotatably contacts the third slider, and is attached to the rotary table. Two slip rings,
A temperature measuring device electrically connected to the fourth slider;
The thermal spraying system according to any one of claims 1 to 6, further comprising: Forming a MCrAlY alloy (M: Ni, Co, Fe or a combination of these elements) layer on at least a part of the substrate;
Rotating the first portion of the substrate while being heated by a first heating means;
Second heating means for heating the second portion of the rotated substrate by plasma or flame while scanning the second heating means in a direction along the axis of rotation;
Forming a partially stabilized zirconia layer on the second portion of the substrate;
A thermal spraying method comprising:

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