A preparation process of double helix structure thermal barrier coating

Abstract

The present invention discloses a preparation process of a double helix structure thermal barrier coating, comprising the following steps: step 1, establishment and simulation of a thermal barrier coating model; step 2, ceramic layer spraying: using plasma spraying technology to prepare a ceramic layer, and adjusting the thickness of each layer of the plasma sprayed ceramic layer according to the relationship simulated by the software; step 3, preparing a double helix structure thermal barrier coating at different angles: according to the plasma spray gun linear velocity, powder output rate and positioner coordination, the interlayer bonding angle and interlayer effective bonding area of ​​the thermal barrier coating are adjusted by staggered rotation in counterclockwise and clockwise directions to prepare a thermal barrier coating with a double helix structure. The present invention adjusts the interlayer bonding angle of the thermal barrier coating so that it has a double helix structure, and prepares a thermal barrier coating with low thermal conductivity and excellent thermal insulation performance.

Description

Technical Field

[0001] The invention belongs to the field of aerospace engines, and in particular relates to a preparation process of a double-helix structure thermal barrier coating. Background Art

[0002] Thermal barrier coatings (TBCs) are high-temperature application coatings with ceramic coating as the main body and act as heat insulation. They are usually deposited on the surface of high-temperature resistant metals or superalloys. They have the advantages of reducing substrate temperature, high hardness, good chemical stability, preventing high-temperature corrosion, extending the service life of hot end components, increasing engine power and reducing fuel consumption.

[0003] At present, the normal operation of high-temperature components in combustion chambers such as boilers, internal combustion engines, gas turbines, and aerospace engines cannot be separated from thermal insulation protection measures. Ceramic coatings are the first choice for thermal insulation treatment of high-temperature components. Ceramic coatings can reduce thermal conductivity by changing their materials or structures, so that they can better protect high-temperature components. Changing the structure of ceramic coatings can be achieved by adjusting the preparation process. The thermal barrier coating prepared by atmospheric plasma spraying technology (APS) has a layered structure. Changing the interlayer bonding angle of the layered structure so that it has a double helix structure can effectively extend the transfer path of heat flow, thereby effectively reducing the thermal conductivity of the thermal barrier coating; under a certain ceramic layer thickness, reducing the thickness of each ceramic layer can increase the number of heat exchanges between ceramic layers, increase thermal resistance, and further reduce the thermal conductivity of the thermal barrier coating. On the other hand, reducing the effective bonding area between ceramic layers of the thermal barrier coating can reduce the thermal conductivity of the thermal barrier coating and improve the thermal insulation effect.

[0004] In view of this, the present invention is proposed. By adjusting the relationship between the linear velocity of the ion spray gun and the powder output rate, the thickness of each plasma sprayed ceramic layer is adjusted. At the same time, according to the synergistic effect of the plasma spray gun and the positioner, the interlayer bonding angle, interlayer effective bonding area and single-pass layer thickness of the thermal barrier coating can be effectively adjusted, and the double-helix structure thermal barrier coating with low thermal conductivity and good thermal insulation effect can be optimized and prepared to adapt to the harsh high-temperature working environment of engine components. Summary of the invention

[0005] The purpose of the present invention is to provide a preparation process of a double helix structure thermal barrier coating, aiming to improve the thermal insulation performance of the thermal barrier coating.

[0006] The present invention is achieved by a process for preparing a double helix structure thermal barrier coating, comprising the following steps:

[0007] Step 1: Establishment and simulation of thermal barrier coating model: Before preparing thermal barrier coating, firstly use Solidworks software to model thermal barrier coatings with different double helix angles, and then use SolidWorks Simulation software to simulate the relationship between the interlayer bonding angle of thermal barrier coating, the effective bonding area of ​​interlayer bonding and the thermal conductivity of thermal barrier coating. By alternating counterclockwise and clockwise rotation to change the interlayer bonding heat transfer angle, the interlayer structure presents a double helix structure.

[0008] Step 2: Preparation of ceramic layer: using plasma spraying technology to prepare the ceramic layer, and adjusting the thickness of each plasma sprayed ceramic layer according to the relationship simulated by the software;

[0009] Step 3. Prepare double-helix structure thermal barrier coatings with different angles: According to the plasma spray gun linear speed, powder output rate and positioner control, the thermal barrier coating interlayer bonding angle and interlayer effective bonding area are adjusted by alternating counterclockwise and clockwise rotation to prepare a thermal barrier coating with a double-helix structure.

[0010] In a further technical solution, in step 2: the thickness of each layer of the ceramic layer is adjusted according to the relationship between the plasma spray gun linear speed and the powder output rate;

[0011] The thickness of each sprayed ceramic layer is 0.01mm, 0.015mm, 0.02mm or 0.025mm;

[0012] The corresponding plasma spray gun linear speed is 0.3m / s, 0.6m / s, 0.9m / s or 1.1m / s;

[0013] And the powder output rate of the plasma spray gun is 3g / s, 6g / s, 10g / s or 15g / s.

[0014] A further technical solution, in the step three: the method of adjusting the interlayer bonding angle and the interlayer effective bonding area of ​​the thermal barrier coating is to adjust the verticality of the plasma spray gun and the workpiece, first prepare the first ceramic layer; the second ceramic layer: use a positioner to rotate the workpiece horizontally clockwise 15-75 degrees; the third ceramic layer: use a positioner to rotate the workpiece horizontally counterclockwise 15-75 degrees; the subsequently prepared ceramic layers are prepared according to this rule until the corresponding thickness is stopped.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The invention provides a preparation process for a double helix structure thermal barrier coating, which adjusts the interlayer heat exchange angle of the layered structure by clockwise and counterclockwise staggered rotation, so that the interlayer structure is a double helix structure, reduces the effective interlayer bonding area and the single layer thickness, while increasing the number of heat exchanges and increasing thermal resistance, thereby reducing the thermal conductivity of the thermal barrier coating. At 1100°C, the thermal conductivity is distributed in the range of 0.859W / m·K-0.925W / m·K. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 , Figure 2 They are the model and top view of the thermal barrier coating with an interlayer bonding angle of 15°.

[0018] Figure 3 , Figure 4 They are the model and top view of the thermal barrier coating with an interlayer bonding angle of 45°.

[0019] Figure 5 , Figure 6 They are the model and top view of the thermal barrier coating with an interlayer bonding angle of 75°.

[0020] Figure 7 This is a bar graph showing the variation of thermal conductivity of thermal barrier coatings with temperature when the interlayer bonding angles are 15°, 45°, and 75°. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0023] Example 1

[0024] A method for preparing a double helix structure thermal barrier coating on a nickel-based alloy surface according to the present invention comprises the following steps:

[0025] Before preparing the thermal barrier coating, the thermal conductivity of the thermal barrier coating is simulated by SolidWorks Simulation software;

[0026] Adjust the plasma spray gun linear speed to 1.1m / s and the powder output rate to 3g / s, and adjust the thickness of each plasma sprayed ceramic layer to 0.01mm;

[0027] The angle between the plasma spray gun and the workpiece is adjusted to 90 degrees. After each layer of ceramic coating is prepared, the positioner adjusts the workpiece to rotate 15 degrees clockwise and counterclockwise.

[0028] The thermal barrier coating was prepared by conventional plasma spraying method, and the coating thickness reached 0.200mm. The interlayer bonding area of ​​the prepared thermal barrier coating was 4.9142mm 2 / 10mm 2 On the cross section, the thermal conductivity is 0.925 W / m·K at 1100°C.

[0029] Example 2

[0030] A method for preparing a thermal barrier coating with a double helix structure on a nickel-based alloy surface according to the present invention comprises the following steps:

[0031] Before preparing the thermal barrier coating, the thermal conductivity of the thermal barrier coating is simulated by SolidWorks Simulation software;

[0032] The plasma spray gun linear speed was adjusted to 0.9 m / s and the powder output rate was adjusted to 6 g / s, and the thickness of each plasma sprayed ceramic layer was adjusted to 0.015 mm;

[0033] The angle between the plasma spray gun and the workpiece is adjusted to 90 degrees. After each layer of ceramic coating is prepared, the positioner adjusts the workpiece to rotate 45 degrees clockwise or counterclockwise horizontally;

[0034] The thermal barrier coating was prepared by conventional plasma spraying method, and the coating thickness reached 0.210mm. The interlayer bonding area of ​​the prepared thermal barrier coating was 4.9026mm 2 / 10mm 2 On the cross section, the thermal conductivity is 0.901 W / m·K at 1100°C.

[0035] Example 3

[0036] A method for preparing a double helix structure thermal barrier coating on a nickel-based alloy surface according to the present invention comprises the following steps:

[0037] Before preparing the thermal barrier coating, the thermal conductivity of the thermal barrier coating is simulated by SolidWorks Simulation software;

[0038] The plasma spray gun linear speed was adjusted to 0.6 m / s and the powder output rate was adjusted to 10 g / s, and the thickness of each plasma sprayed ceramic layer was adjusted to 0.02 mm;

[0039] The angle between the plasma spray gun and the workpiece is adjusted to 90 degrees. After each layer of ceramic coating is prepared, the positioner adjusts the workpiece to rotate 75 degrees clockwise or counterclockwise horizontally;

[0040] The thermal barrier coating was prepared by conventional plasma spraying method, and the coating thickness reached 0.22mm. The interlayer bonding area of ​​the prepared thermal barrier coating was 4.914mm2 / 10mm 2 On the cross section, the thermal conductivity is 0.859 W / m·K at 1100°C.

[0041] Example 4

[0042] A method for preparing a double helix structure thermal barrier coating on a nickel-based alloy surface according to the present invention comprises the following steps:

[0043] Before preparing the thermal barrier coating, the thermal conductivity of the thermal barrier coating is simulated by SolidWorks Simulation software;

[0044] Adjust the moving speed of the plasma spray gun to 1.1m / s and the powder feeding rate to 15g / s, and adjust the thickness of each plasma sprayed ceramic layer to 0.025mm;

[0045] The angle between the plasma spray gun and the workpiece is adjusted to 90 degrees. After each layer of ceramic coating is prepared, the positioner adjusts the workpiece to rotate 30 degrees clockwise or counterclockwise horizontally;

[0046] The thermal barrier coating was prepared by conventional plasma spraying method, and the coating thickness reached 0.25mm. The interlayer bonding area of ​​the prepared thermal barrier coating was 4.8904mm 2 / 10mm 2 On the cross section, the thermal conductivity is 0.868 W / m·K at 1100°C.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A preparation process for a double helix structure thermal barrier coating. It is characterized in that The following steps are involved: Step 1: Establishment and simulation of thermal barrier coating model: Before preparing thermal barrier coating, firstly use Solidworks software to model thermal barrier coatings with different double helix angles, and then use SolidWorks Simulation software to simulate the relationship between the interlayer bonding angle of thermal barrier coating, the effective bonding area of ​​interlayer bonding and the thermal conductivity of thermal barrier coating. By alternating counterclockwise and clockwise rotation to change the interlayer bonding heat transfer angle, the interlayer structure presents a double helix structure. Step 2: Preparation of ceramic layer: using plasma spraying technology to prepare the ceramic layer, and adjusting the thickness of each plasma sprayed ceramic layer according to the relationship simulated by the software; Step 3: Prepare double helix structure thermal barrier coatings with different angles: According to the plasma spray gun linear speed, powder output rate and positioner control, the thermal barrier coating interlayer bonding angle and interlayer effective bonding area are adjusted by alternating counterclockwise and clockwise rotation to prepare a thermal barrier coating with a double helix structure; In the step 2: the thickness of each ceramic layer is adjusted according to the relationship between the plasma spray gun linear speed and the powder output rate; In the step 2: the thickness of each sprayed ceramic layer is 0.01 mm, 0.015 mm, 0.02 mm or 0.025 mm; The corresponding plasma spray gun linear speed is 0.3m / s, 0.6m / s, 0.9m / s or 1.1m / s; and the powder output rate of the plasma spray gun is 3g / s, 6g / s, 10g / s or 15g / s; In the step three, the method of adjusting the interlayer bonding angle and the interlayer effective bonding area of ​​the thermal barrier coating is to adjust the verticality of the plasma spray gun and the workpiece. After the positioner completes the preparation of each layer of ceramic coating, the workpiece rotates horizontally clockwise and counterclockwise by 15-75 degrees. The subsequent ceramic layers are prepared according to this rule until the corresponding thickness is stopped.

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