CN114540738A - A kind of preparation method of ultra-high temperature anti-scour thermal barrier coating - Google Patents

Abstract

The invention relates to a preparation method of an ultrahigh-temperature anti-erosion thermal barrier coating, which comprises the following steps: providing a high-temperature alloy matrix; depositing a metal bonding layer on the superalloy substrate; introducing a grid bonding layer with the same component as the metal bonding layer on the metal bonding layer by utilizing a laser engraving technology or a laser coaxial powder feeding 3D printing technology, wherein the grid bonding layer is composed of a rectangular grid structure with a regular shape and protrudes from the metal bonding layer, the side length of the rectangular grid is between 100 and 900 mu m, and the height of the grid bonding layer is between 100 and 400 mu m; depositing a ceramic layer on the mesh bonding layer. According to the preparation method of the ultrahigh-temperature anti-scouring thermal barrier coating, the continuous grid layer with a regular shape is introduced between the bonding layer and the ceramic layer, so that the roughness of the interface between the bonding layer and the ceramic layer is increased, the mechanical bonding strength of the interface is enhanced, and the service temperature of the thermal barrier coating is improved.

Description

A kind of preparation method of ultra-high temperature anti-scour thermal barrier coating

technical field

The present invention relates to thermal barrier coatings, and more particularly to a preparation method of ultra-high temperature anti-scouring thermal barrier coatings.

Background technique

With the development of modern industry, higher service temperature requirements are put forward for hot-end components such as aero-engines. At higher service temperatures, both superalloy substrates and thermal protective coatings face higher performance requirements. Excessive temperature leads to oxidation and high temperature creep of the alloy surface matrix, which eventually leads to the failure of the superalloy. The thermal barrier coating can make full use of the superior low thermal conductivity of ceramic materials, and couple the ceramic with the high temperature substrate by coating to achieve the purpose of improving the service life and efficiency of the hot end components.

The thermal barrier coating mainly used at present is a double-layer thermal barrier coating, which is composed of a ceramic layer with thermal insulation on the surface and a metal bonding layer. Usually, the surface thermal insulation ceramic layer is made of traditional 8% Y ₂ O ₃ doped ZrO ₂ material, which has excellent properties such as low thermal conductivity, good fracture toughness, and high thermal expansion coefficient. The metal bonding layer material is generally MCrAlY (where M is Ni or Co) material, which is composed of γ phase and β-NiAl phase, and mainly provides oxidation resistance and interface bonding strength for the superalloy matrix.

However, with the continuous improvement of the requirements for the thrust-weight ratio of aero-engines and the efficiency of gas turbines, new requirements are put forward for the service temperature of thermal barrier coatings and their anti-scour properties. During the long-term service of the engine, due to the action of inertial force, the hard particles deviate from the air flow to scour the coating surface and eventually lead to failure. Hard particles mainly come from particles generated during the combustion process or inhaled external sand, dust and other objects. Moreover, with the increase of the service temperature of thermal barrier coatings, the problem of scouring failure has become particularly prominent, and how to improve the high temperature scour resistance of thermal barrier coatings has also become particularly important.

However, it is difficult for thermal barrier coatings prepared by plasma spraying technology or electron beam physical deposition technology to have both ultra-high temperature resistance and erosion resistance. Therefore, how to prepare ultra-high temperature anti-scour thermal barrier coatings through innovative methods such as structure and new material design has become an urgent problem to be solved.

SUMMARY OF THE INVENTION

In order to solve the problem that the thermal barrier coating in the prior art is difficult to have both ultra-high temperature resistance and anti-scour performance, the present invention provides a preparation method of an ultra-high temperature anti-scouring thermal barrier coating.

The preparation method of the ultra-high temperature anti-scour thermal barrier coating according to the present invention includes the following steps: S1, providing a superalloy base; S2, depositing a metal bonding layer on the superalloy base; S3, engraving with a laser Technology or laser coaxial powder feeding 3D printing technology introduces a grid bonding layer with the same composition as the metal bonding layer on the metal bonding layer, and the grid bonding layer is composed of a rectangular grid structure with regular shape and protruding from the metal bonding layer, the side length of the rectangular grid is between 100-900 μm, and the height of the grid bonding layer is between 100-400 μm; S4, on the grid bonding layer A ceramic layer is deposited thereon.

Preferably, the superalloy matrix is a Hastelloy superalloy, a Ni-based single crystal superalloy or a DZ125 superalloy. More preferably, in the step S1, rust removal, ultrasonic cleaning and sandblasting are performed on the superalloy substrate.

Preferably, in the step S2, a metal bonding layer is deposited on the superalloy substrate by supersonic flame spraying or plasma spraying.

Preferably, the metal bonding layer is an MCrAlY coating, and the grid bonding layer is an MCrAlY network structure layer, wherein M is one or both of Ni and Co. In a preferred embodiment, the metal bonding layer is a NiCrAlY coating. In another preferred embodiment, the metal bonding layer is a CoCrAlY coating. In yet another preferred embodiment, the metal bonding layer is a NiCoCrAlY coating.

Preferably, the metal bonding layer is a YHf micro-doped AlCrCoFeNi high-entropy bonding layer, and the mesh bonding layer is a YHf micro-doped AlCrCoFeNi network structure layer.

Preferably, the atomic content of the Al element is in the range of 10-30%, the atomic content of the YHf element is in the range of 0.2-0.5%, and the atomic content of the remaining elements is in the range of 10-40%. More preferably, the atomic content of Al element is in the range of 10-20%, the atomic content of YHf element is in the range of 0.2-0.5%, and the atomic content of the remaining elements is in the range of 20-22.5%. In a preferred embodiment, the atomic content of Al, Cr, Co, Fe, and Ni are all 20%, and the atomic content of doped YHf is 0.2%. In another preferred embodiment, the atomic content of Al is 10%, the atomic content of Cr, Co, Fe, and Ni is 22.5%, and the atomic content of doped YHf is 0.5%.

Preferably, the thickness of the metal bonding layer is 60-300 μm. More preferably, the thickness of the metal bonding layer is 100-300 μm. More preferably, the thickness of the metal bonding layer is 100-200 μm.

Preferably, in the step S3, the metal bonding layer is melted by a high-energy laser beam, and the desired grid structure with regular shape is obtained by controlling parameters such as the diameter, power, and scanning speed of the laser beam.

Preferably, in the step S3, the rated power of the used laser is 0.5-1kW, the spot diameter of the laser beam is 0.3-0.9mm, the power of the laser is 60-120W, and the scanning speed is 5-15mm/s.

Preferably, in the step S3, the flow rate of the molten pool under argon protection is 5L/min, and the powder feeding amount of the metal powder is 1-9g/min.

Preferably, the step S4 includes: S41, depositing an 8YSZ ceramic layer on the grid bonding layer; S42, depositing a YAG ceramic layer on the 8YSZ ceramic layer. The YAG ceramic layer deposited on the surface can effectively prevent particle erosion, thereby improving the erosion resistance of the thermal barrier coating.

Preferably, the thickness of the 8YSZ ceramic layer is 400-700 μm, and the thickness of the YAG ceramic layer is 50-200 μm.

Preferably, the step S4 includes: depositing a composite coating of YSZ and YAG on the grid bonding layer. The laser engraving technology and the design of the composite coating make the thermal barrier coating have excellent high temperature resistance and erosion resistance.

Preferably, the thickness of the composite coating is 550-900 μm.

Preferably, the step S4 includes: S41, depositing an 8YSZ ceramic layer on the grid bonding layer; S42, densifying the surface of the 8YSZ ceramic layer by laser treatment to obtain a dense ceramic layer. The dense ceramic layer can be used as an anti-particle scour surface, which can greatly improve the anti-particle scour performance of the thermal barrier coating at high service temperatures. The technology of laser 3D printing combined with laser densification finally enables the thermal barrier coating to obtain excellent high temperature resistance and erosion resistance.

Preferably, in step S42, the energy density of the semiconductor laser transmitter used is 10.0-12.9 J/mm ² , and the laser spot size is 10 mm×1.5 mm.

Preferably, the thickness of the 8YSZ ceramic layer is 300-900 μm, and the thickness of the dense ceramic layer is 20-100 μm. More preferably, the thickness of the 8YSZ ceramic layer is 600-800 μm, and the thickness of the dense ceramic layer is 50-100 μm.

Preferably, in step S4, a ceramic layer is deposited on the grid bonding layer by plasma spraying. Plasma spraying is the use of plasma beam to melt ceramic powder, and then spray to form a layered structure coating. Preheat the substrate 2-3 times before spraying. The specific parameters of plasma spraying include: the distance between the spray gun and the substrate is 80-100mm, the moving speed of the spray gun is 300-600mm/s, the powder feeding rate is 20-70g/min, the powder feeding air flow is 0.5-1.2L/min, and the spraying speed is 300-600mm/s. The voltage is 100-200V, the spraying current is 150-250A, the flow rate of argon gas is 20-120L/min, and the flow rate of hydrogen gas is 10-50L/min.

According to the preparation method of the ultra-high temperature anti-scouring thermal barrier coating of the present invention, a continuous grid layer with regular shape is introduced between the bonding layer and the ceramic layer by using the laser engraving technology or the laser coaxial powder feeding 3D printing technology, increasing the The roughness of the interface between the bonding layer and the ceramic layer enhances the mechanical bonding strength of the interface, thereby increasing the service temperature of the thermal barrier coating (for example, an ultra-high temperature environment of 1200°C-1600°C). At the same time, in the process of thermal service, the protruding mesh can effectively hinder the expansion of cracks, which is conducive to the uniform release of stress. Specifically, the grid bonding layer is provided by a rectangular grid structure with a given shape, thereby improving the mechanical bonding force; the grid bonding layer is provided by a rectangular grid structure with regular shapes, thereby avoiding local mechanical The bonding force is weakened and the coating is peeled off; different grid bonding layers can be obtained by adjusting the parameters (side length and height) of the rectangular grid.

Description of drawings

1 is a schematic cross-sectional view of an ultra-high temperature anti-scouring thermal barrier coating according to a preferred embodiment of the present invention, wherein w refers to the total width of the top arc surface on the grid, h refers to the grid height, and L refers to the grid height. is the grid width or grid spacing;

FIG. 2 is an exploded view of the ultra-high temperature anti-scour thermal barrier coating of FIG. 1;

FIG. 3 is a top view of the mesh adhesive layer of FIG. 2 .

Detailed ways

Below in conjunction with the accompanying drawings, preferred embodiments of the present invention are given and described in detail.

Example 1

In step 1, the superalloy substrate 1 (see Figure 1-Figure 2) (ie Hastelloy superalloy) is ground, ultrasonically cleaned, and pretreated by sandblasting. The sandblasting process adopts alumina with a particle size of 20-100 meshes to obtain relatively uniform roughness.

In step 2, a metal bonding layer 2 (refer to FIG. 1-FIG. 2) (ie, MCrAlY coating) is deposited on the superalloy substrate 1 by supersonic flame spraying, wherein M is one or both of Ni and Co, The thickness is about 200 μm.

Step 3, using laser engraving technology to introduce the grid bonding layer 3 (see Figure 1-Figure 2) (ie, the MCrAlY network structure layer) with the same composition as the metal bonding layer 2 on the surface of the metal bonding layer 2, the adopted The rated power of the fiber laser is 1kW, the diameter of the laser beam spot is 0.9mm, the laser power is 120W, the scanning speed is 5mm/s, the height h of the grid (ie the grid bonding layer) is 400μm, and the grid width L (ie the side length) ) is 100 μm. Referring to FIG. 1 , the mesh bonding layer 3 protrudes upward from the surface of the metal bonding layer 2 to form a convex arc surface, which is determined by the above-mentioned parameters such as laser beam diameter, power, and scanning speed of the laser engraving technology. Specifically, the grid bonding layer 3 includes a plurality of regularly-shaped rectangular grids formed by parallel spaced warp threads and parallel spaced weft threads, each rectangular grid having the same size, as shown in FIG. 3 . It should be understood that the arc surface is deposited by laser melting powder, the total width w of the top arc surface on the grid is determined by the diameter of the laser spot, the grid height h can be controlled by the number of scans, etc., and the final curvature can be determined by the ratio of h/w. It is worth noting that it can be controlled by parameters in the range of about 0.22-1.

In step 4, a layer of 8YSZ ceramic layer 4 (refer to FIG. 1 to FIG. 2 ) is deposited on the surface of the grid bonding layer 3 by using the plasma spraying technology, and the thickness is about 700 μm.

Step 5, depositing a YAG ceramic layer 5 on the surface of the 8YSZ ceramic layer 4 (see FIG. 1 to FIG. 2 ) with a thickness of 200 μm, and the total thickness of the 8YSZ ceramic layer 4 and the YAG ceramic layer 5 is 900 μm.

After the thermal cycle test at 1150°C, the thermal cycle life of the thermal barrier coating of the present invention is higher than that of the traditional thermal barrier coating, which is mainly because the grid bonding layer 3 increases the ceramic layer (ie 8YSZ ceramic layer). The interface roughness between the layer 4 and the YAG ceramic layer 5) and the metal bonding layer 2 improves the interface bonding strength, thereby prolonging the service life and service temperature. In addition, the introduction of the YAG ceramic layer 5 significantly improves the surface erosion resistance of the thermal barrier coating. The combination of the design of the 8YSZ ceramic layer 4 and the YAG ceramic layer 5 and the laser engraving technology enables the thermal barrier coating to be applied to the service environment with higher temperature and more resistance to erosion.

Example 2

Step 1, grinding, ultrasonic cleaning, and sandblasting pretreatment on the superalloy substrate 1 (ie, Ni-based single crystal superalloy).

In step 2, a metal bonding layer 2 (ie, a YHf micro-doped AlCrCoFeNi high-entropy bonding layer) is deposited on the superalloy substrate 1 by plasma spraying, with a thickness of about 200 μm, the atomic content of AlCrCoFeNi is 20%, and the doped YHf The atomic content is 0.2%.

Step 3, use laser engraving technology to introduce grid bonding layer 3 with the same composition as metal bonding layer 2 (ie, YHf micro-doped AlCrCoFeNi network structure layer) on the surface of metal bonding layer 2. The fiber laser used is rated for The power is 0.5 kW, the diameter of the laser beam spot is 0.3 mm, the laser power is 60 W, the scanning speed is 15 mm/s, the grid height h is 100 μm, and the grid width L is 900 μm.

In step 4, a layer of 8YSZ ceramic layer 4 with a thickness of about 500 μm is deposited on the surface of the grid bonding layer 3 by using the plasma spraying technology.

In step 5, a YAG ceramic layer 5 is deposited on the surface of the 8YSZ ceramic layer 4 with a thickness of 50 μm, and the total thickness of the 8YSZ ceramic layer 4 and the YAG ceramic layer 5 is 550 μm.

Compared with the MCrAlY bonding layer in Example 1, the YHf micro-doped AlCrCoFeNi bonding layer used in this embodiment has better oxidation resistance. After the thermal cycle test at 1200°C, its service life is longer than that of Example 1. Anti-scour experiments show that the anti-scour effects of Example 1 and Example 2 are basically the same.

Example 3

Step 1, grinding, ultrasonic cleaning, and sandblasting pretreatment on the superalloy base 1 (ie, DZ125 superalloy).

Step 2, deposit a metal bonding layer 2 (ie, a YHf micro-doped AlCrCoFeNi high-entropy bonding layer) on the superalloy substrate 1 by plasma spraying, the thickness is about 100 μm, the Al atomic content is 10%, Cr, Co, Fe , Ni atomic content is 22.5%, and the doped YHf atomic content is 0.5%.

Step 3, use laser engraving technology to introduce grid bonding layer 3 with the same composition as metal bonding layer 2 (ie, YHf micro-doped AlCrCoFeNi network structure layer) on the surface of metal bonding layer 2. The fiber laser used is rated for The power is 0.8kW, the laser beam spot diameter is 0.6mm, the laser power is 90W, the scanning speed is 10mm/s, the grid height h is 150μm, and the grid width L is 600μm.

In step 4, a layer of 8YSZ ceramic layer 4 with a thickness of about 500 μm is deposited on the surface of the grid bonding layer 3 by using the plasma spraying technology.

In step 5, a YAG ceramic layer 5 is deposited on the surface of the 8YSZ ceramic layer 4 with a thickness of 50 μm, and the total thickness of the 8YSZ ceramic layer 4 and the YAG ceramic layer 5 is 550 μm.

Compared with Example 2, after the thermal cycle test at 1200°C, its service life is longer than that of Example 2. Anti-scour experiments show that the anti-scour effects of Example 1 and Example 2 are basically the same.

Example 4

Step 1, performing rust removal, ultrasonic cleaning and sandblasting pretreatment on the superalloy substrate 1 (ie, Hastelloy).

Step 2, using supersonic flame spraying to prepare metal bonding layer 2 (ie NiCoCrAlY metal bonding layer) with a thickness of 300 μm.

Step 3: Prepare grid bonding layer 3 (ie NiCoCrAlY grid layer) on the surface of metal bonding layer 2 by laser coaxial powder feeding 3D printing technology. The rated power of the fiber laser used is 1kW, and the diameter of the laser beam spot is 0.9mm. , the laser power is 120W, the scanning speed is 15mm/s, the flow rate of the molten pool under argon protection is 5L/min, the powder feeding amount of the metal powder is 9g/min, the resulting grid height h is 400μm, and the grid width L is 900μm. Referring to FIG. 1, the mesh bonding layer 3 is arched upward from the surface of the metal bonding layer 2 to form a convex arc surface, which is the above-mentioned laser beam diameter, power, scanning speed, It is determined by parameters such as argon protection molten pool flow and powder feeding amount. Specifically, the grid bonding layer 3 includes a plurality of regularly-shaped rectangular grids formed by parallel spaced warp threads and parallel spaced weft threads, each rectangular grid having the same size, as shown in FIG. 3 .

In step 4, a 300 μm 8YSZ ceramic layer is deposited on the surface of the grid layer by using the plasma spraying technology.

Step 5, using laser densification technology to obtain a dense layer 5 with a thickness of 100 μm, the energy density of the semiconductor laser transmitter used in the laser densification is 12.9 J/mm ² , and the laser spot size is 10 mm×1.5 mm.

The 1150 ℃ thermal cycle test results and the anti-scour test results show that compared with the traditional thermal barrier coating, the thermal cycle life and the anti-scour depth are greatly improved.

Example 5

In step 1, the superalloy substrate 1 (ie, the Ni-based single crystal alloy) is subjected to rust removal, ultrasonic cleaning and sandblasting pretreatment.

In step 2, a metal bonding layer 2 (ie, a YHf micro-doped AlCrCoFeNi metal bonding layer) is prepared by plasma spraying, and the thickness is 300 μm.

Step 3: Prepare grid bonding layer 3 (ie, YHf micro-doped AlCrCoFeNi grid layer) on the surface of metal bonding layer 2 by laser coaxial powder feeding 3D printing technology. The atomic content of AlCrCoFeNi is 20%, and the atomic content of YHf is 20%. is 0.2%, the rated power of the fiber laser used is 0.5kW, the diameter of the laser beam spot is 0.6mm, the laser power is 60W, the scanning speed is 5mm/s, the flow rate of the molten pool under argon protection is 5L/min, and the powder feeding amount of the metal powder is For 1 g/min, the grid height h is 100 μm, and the grid width L is 100 μm.

In step 4, a 900 μm 8YSZ ceramic layer is deposited on the surface of the grid layer by using the plasma spraying technology.

Step 5, using the laser densification technology to obtain a dense layer with a thickness of 50 μm, the energy density of the semiconductor laser transmitter used in the laser densification is 10.0 J/mm ² , and the laser spot size is 10 mm×1.5 mm.

The 1200 ℃ thermal cycle test results and the anti-scour test results show that, compared with Example 4, the thermal barrier coating using the high-entropy bonding layer has a higher thermal cycle life, and its anti-scour effect is basically the same as that of Example 4.

Example 6

Step 1, perform rust removal, ultrasonic cleaning and sandblasting pretreatment on the superalloy substrate 1 (ie, DZ125 single crystal alloy).

In step 2, a metal bonding layer 2 (ie, a YHf micro-doped AlCrCoFeNi metal bonding layer) is prepared by plasma spraying, and the thickness is 100 μm.

Step 3: Prepare grid bonding layer 3 (ie, YHf micro-doped AlCrCoFeNi grid layer) on the surface of metal bonding layer 2 by laser coaxial powder feeding 3D printing technology. The atomic content of CrCoFeNi is 22.5%, and the atomic content of Al is 22.5%. is 10%, the YHf atomic content is 0.2%, the rated power of the fiber laser used is 0.7kW, the diameter of the laser beam spot is 0.8mm, the laser power is 90W, the scanning speed is 10mm/s, and the flow rate of the molten pool under argon protection is 5L/min. , the feeding amount of metal powder is 5g/min, the grid height h is 200μm, and the grid width L is 200μm.

In step 4, a 600 μm 8YSZ ceramic layer is deposited on the surface of the grid bonding layer 3 by using the plasma spraying technology.

Step 5, using the laser densification technology to obtain a dense layer with a thickness of 70 μm, the energy density of the semiconductor laser transmitter used in the laser densification is 11.0 J/mm ² , and the laser spot size is 10 mm×1.5 mm.

The thermal cycle test results at 1200°C and the anti-scour test results show that the thermal cycle life and the anti-scour effect are basically the same as those in Example 5.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Various changes can be made to the above-mentioned embodiments of the present invention. That is, all simple and equivalent changes and modifications made according to the claims and descriptions of the present invention fall into the protection scope of the claims of the present invention. What is not described in detail in the present invention is conventional technical content.

Claims (10)

1. A preparation method of an ultrahigh-temperature anti-erosion thermal barrier coating is characterized by comprising the following steps:

s1, providing a high-temperature alloy substrate;

s2, depositing a metal bonding layer on the high-temperature alloy substrate;

s3, introducing a grid bonding layer with the same components as the metal bonding layer on the metal bonding layer by utilizing a laser engraving technology or a laser coaxial powder feeding 3D printing technology, wherein the grid bonding layer is composed of a rectangular grid structure with a regular shape and protrudes from the metal bonding layer, the side length of the rectangular grid is between 100 and 900 microns, and the height of the grid bonding layer is between 100 and 400 microns;

s4, depositing a ceramic layer on the grid bonding layer.

2. The method of claim 1, wherein the metal bond coat is a MCrAlY coating and the mesh bond coat is a MCrAlY mesh structure layer, wherein M is one or both of Ni and Co.

3. The method of claim 1, wherein the metal bonding layer is an YHf micro-doped AlCrCoFeNi high-entropy bonding layer, and the grid bonding layer is a YHf micro-doped AlCrCoFeNi mesh layer.

4. The method according to claim 3, wherein the atomic content of Al element is in the range of 10 to 30%, the atomic content of YHf element is in the range of 0.2 to 0.5%, and the atomic content of the remaining elements is in the range of 10 to 40%.

5. The production method according to claim 1, wherein in the step S3, a laser having a rated power of 0.5 to 1kW, a spot diameter of a laser beam of 0.3 to 0.9mm, a power of a laser of 60 to 120W, and a scanning speed of 5 to 15mm/S is used.

6. The method of claim 1, wherein in step S3, the flow rate of the argon shield molten pool is 5L/min, and the powder feeding amount of the metal powder is 1-9 g/min.

7. The method for preparing a composite material according to claim 1, wherein the step S4 includes:

s41, depositing an 8YSZ ceramic layer on the grid bonding layer;

s42, depositing a YAG ceramic layer on the 8YSZ ceramic layer.

8. The method for preparing a composite material according to claim 1, wherein the step S4 includes: and depositing a composite coating of YSZ and YAG on the grid bonding layer.

9. The method for preparing a composite material according to claim 1, wherein the step S4 includes:

s41, depositing an 8YSZ ceramic layer on the grid bonding layer;

and S42, densifying the surface of the 8YSZ ceramic layer by using laser treatment to obtain a dense ceramic layer.

10. The manufacturing method of claim 9, wherein, in step S42, the semiconductor laser emitter used has an energy density of 10.0 to 12.9J/mm²The laser spot size is 10mm × 1.5 mm.

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