Laser pretreatment process, high bonding performance ceramic coating and preparation process

Abstract

The present invention provides a laser pretreatment process, a high-bonding performance ceramic coating and a preparation process. The laser pretreatment process includes the following steps: S1, using a laser primary cleaning process to clean the substrate surface; S2, using a laser etching process to etch the cleaned substrate surface; S3, using a laser secondary cleaning process to clean the etched substrate surface. Compared with the prior art, the laser pretreatment process described in the present invention is a process in which the substrate surface is pretreated by a laser primary cleaning process, a laser etching process and a laser secondary cleaning process. The laser primary cleaning process, the laser etching process and the laser secondary cleaning process are interrelated and synergistic. On the one hand, the surface area of ​​the substrate after pretreatment can be more effectively increased; on the other hand, the surface oxide layer after laser etching can be effectively removed. Under the joint action of these two aspects, the bonding performance of the substrate and the ceramic coating after the laser pretreatment process is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of plasma spraying ceramic coatings, and in particular to a laser pretreatment process, a high-bonding performance ceramic coating and a preparation process. Background Art

[0002] At present, the pretreatment method in plasma spraying mainly adopts sandblasting pretreatment, which has the disadvantages of easy deformation and serious pollution when processing small and thin workpieces, and the bonding strength of the aluminum oxide titanium ceramic coating based on sandblasting pretreatment is only 20-30MPa. In the article "Performance of plasma sprayed Al2O3-TiO2 coating and its application in aviation engine comb seal" in the 4th issue of "Material Protection" in 2022, the average bonding strength of the aluminum oxide titanium coating prepared by sandblasting pretreatment is only 25.2MPa; in the article "Research on Process Parameter Optimization of Plasma Sprayed Al2O3-3%TiO2 Composite Coating on Aluminum Alloy Surface" in the fifth issue of "Surface Technology" in 2019, the average bonding strength of the aluminum oxide titanium coating prepared by sandblasting pretreatment is only 25.2MPa. When the aluminum oxide titanium coating with limited bonding strength is used on parts with high load-bearing requirements such as power transmission shafts, the coating will peel off, causing the coating to fail.

[0003] The patent with application number CN201810840858.7 in the prior art discloses a sandblasting process suitable for plasma spraying, including the following steps: Step 1, cleaning, removing impurities and drying the workpiece substrate; Step 2, coating and shielding the non-spraying surface of the workpiece; Step 3, sandblasting the spraying surface of the fixed workpiece substrate, the sandblasting pressure is 0.2-0.4Mpa, and the sandblasting height is 20-100cm. Although the patent increases the roughness of the workpiece substrate surface through the sandblasting process and provides a clean bonding interface, which helps to improve the quality of subsequent coatings, the bonding strength between the coating and the workpiece substrate is limited due to the pretreatment of the collective through the sandblasting process. When the aluminum oxide titanium coating is used on parts with high load-bearing requirements such as power transmission shafts, the coating will peel off, causing the coating to fail.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to propose a laser pretreatment process, a high-bonding performance ceramic coating and a preparation process to solve the problem that the bonding strength between the coating based on sandblasting pretreatment and the workpiece substrate is limited in the prior art, and the aluminum oxide titanium coating with limited bonding strength will peel off and cause the coating failure when used on parts with high load-bearing performance requirements such as power transmission shafts.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A laser pretreatment process, the laser pretreatment process comprising the following steps:

[0008] S1. Cleaning the substrate surface using a laser one-time cleaning process;

[0009] S2, etching the cleaned substrate surface using a laser etching process;

[0010] S3. Use a laser secondary cleaning process to clean the surface of the substrate after etching.

[0011] In the laser pretreatment process described in the present invention, the surface of the substrate undergoes a laser primary cleaning process → a laser etching process → a laser secondary cleaning process. The laser primary cleaning process, the laser etching process and the laser secondary cleaning process are interrelated and work synergistically. On the one hand, the surface area of ​​the substrate after pretreatment can be more effectively improved; on the other hand, the dirt and oxide layer on the surface of the substrate before and after laser etching can be effectively removed. Under the joint action of these two aspects, the bonding performance between the substrate and the ceramic coating after the laser pretreatment process is greatly improved, and the problem of coating failure caused by peeling of the aluminum oxide titanium coating can be avoided.

[0012] Furthermore, the power of the laser one-time cleaning process is 10-20W, the frequency is 20KHz, the scanning speed is 1000mm / s, the number of scans is 2 times, and the scanning pattern of the laser one-time cleaning process is a first single-line array, and the array interval of the first single-line array is 0.01mm.

[0013] The parameters of the laser one-time cleaning process are set as above, which can effectively remove the natural oxide layer on the surface of the substrate, and is conducive to etching a better surface of the substrate by the laser etching process.

[0014] Furthermore, the laser etching process comprises the following steps:

[0015] S21, laser one-time etching process;

[0016] S22, laser secondary etching process;

[0017] S23, laser three-time etching process.

[0018] This setting can effectively prepare a substrate surface with a high surface area, and can more effectively improve the bonding performance between the substrate and the ceramic coating.

[0019] Furthermore, the power of the laser one-time etching process is 50-60 W, the frequency is 20 KHz, the scanning speed is 200 mm / s, and the number of scans is 2-4 times. The scanning pattern of the laser one-time etching process is a first three-line combination array, the three-line spacing of the first three-line combination array is 0.02 mm, the array spacing of the first three-line combination array is 0.08-0.14 mm, and the first three-line combination array is perpendicular to the first single-line array.

[0020] The parameters of the laser one-time etching process are within the above range. On the one hand, it can more effectively increase the surface area of ​​the substrate after pretreatment, and the bottom of the prepared surface micro-grooves is sharper, which can form a "chimeric combination" with the coating, thereby more effectively improving the bonding performance of the ceramic coating; on the other hand, the first three-line combination array of the scanning pattern of the laser one-time etching process is perpendicular to the first single-line array of the scanning pattern of the laser one-time cleaning process, which alleviates the stress concentration caused by the single direction and single structure of the microscopic morphology of the substrate surface after pretreatment, thereby more effectively improving the bonding performance of the ceramic coating.

[0021] Furthermore, the power of the laser secondary etching process is 40-60 W, the frequency is 20 KHz, the scanning speed is 1000 mm / s, and the number of scans is 2 times. The scanning pattern of the laser secondary etching process is a second three-line combination array, the three-line spacing of the second three-line combination array is 0.02 mm, the array spacing of the second three-line combination array is 0.08-0.14 mm, and the second three-line combination array is perpendicular to the first single-line array.

[0022] The parameters of the laser secondary etching process are within the above range. On the one hand, it can more effectively increase the surface area of ​​the substrate after pretreatment, and the bottom of the prepared surface micro-grooves is sharper, which can form a "chimeric combination" with the coating, thereby more effectively improving the bonding performance of the ceramic coating; on the other hand, the second three-line combination array of the scanning pattern of the laser secondary etching process is perpendicular to the first single-line array of the scanning pattern of the laser primary cleaning process, which alleviates the stress concentration caused by the single direction and single structure of the microscopic morphology of the substrate surface after pretreatment, thereby more effectively improving the bonding performance of the ceramic coating.

[0023] Furthermore, the power of the three-time laser etching process is 40W, the frequency is 20KHz, the scanning speed is 1000mm / s, and the number of scans is 2 times. The scanning pattern of the three-time laser etching process is a third three-line combination array. The three-line interval of the third three-line combination array is 0.02mm, the array interval of the third three-line combination array is 0.08-0.14mm, and the third three-line combination array is perpendicular to the first single-line array.

[0024] The parameters of the three-time laser etching process are within the above range. On the one hand, it can more effectively increase the surface area of ​​the substrate after pretreatment, and the bottom of the prepared surface micro-grooves is sharper, which can form a "chimeric combination" with the coating, thereby more effectively improving the bonding performance of the ceramic coating; on the other hand, the third three-line combination array of the scanning pattern of the three-time laser etching process is perpendicular to the scanning pattern of the first single-line array of the scanning pattern of the one-time laser cleaning process, which alleviates the stress concentration caused by the single direction and single structure of the microscopic morphology of the substrate surface after pretreatment, and can more effectively improve the bonding performance of the ceramic coating.

[0025] Furthermore, the power of the laser secondary cleaning process is 10-20 W, the frequency is 20 KHz, the scanning speed is 1000 mm / s, and the number of scans is 2 times. The scanning pattern of the laser secondary cleaning process is a second single-line array, and the second single-line array is perpendicular to the first three-line combination array, the second three-line combination array, and the third three-line combination array. The array interval of the second single-line array is 0.01 mm.

[0026] The parameters of the laser secondary cleaning process are within the above range. First, it can effectively remove the surface oxide layer after laser etching to prepare a substrate surface with high cleanliness and high surface area, and the ceramic coating after spraying is better bonded to the substrate; second, the microstructure introduced by the laser secondary cleaning process effectively fills the unprocessed planar area of ​​the laser etching, further increasing the surface area of ​​the substrate after pretreatment; third, the second single-line array of the scanning pattern of the laser secondary cleaning process is perpendicular to the first three-line combination array, the second three-line combination array, and the third three-line combination array, which alleviates the stress concentration caused by the single direction and single structure of the microscopic morphology of the substrate surface after pretreatment, and can more effectively improve the bonding performance of the ceramic coating.

[0027] The second aspect of the present invention proposes a preparation process of a high-bonding performance ceramic coating, which comprises the following steps: firstly pretreating the surface of the substrate using any one of the laser pretreatment processes described, and then spraying the pretreated substrate using a plasma spraying process to obtain a high-bonding performance ceramic coating.

[0028] Furthermore, the process of spraying the pretreated substrate through a plasma spraying process to obtain a high-bonding performance ceramic coating includes the following steps: first, spraying the pretreated substrate through a plasma primary spraying process to obtain a spray base layer, and then spraying the spray base layer through a plasma secondary spraying process to obtain a ceramic layer.

[0029] According to a third aspect of the present invention, a high bonding performance ceramic coating is provided, wherein the high bonding performance ceramic coating is prepared using any one of the processes for preparing the high bonding performance ceramic coating.

[0030] Compared with the prior art, the laser pretreatment process, high bonding performance ceramic coating and preparation process described in the present invention have the following beneficial effects:

[0031] The laser pretreatment process, high-bonding performance ceramic coating and preparation process described in the present invention, the substrate surface is pretreated by laser primary cleaning process → laser etching process → laser secondary cleaning process, and the process parameters of laser primary cleaning process, laser etching process and laser secondary cleaning process are optimized. The laser primary cleaning process, laser etching process and laser secondary cleaning process are interrelated and synergistic. On the one hand, the surface area of ​​the substrate after pretreatment can be more effectively improved; on the other hand, the dirt and oxide layer on the substrate surface before and after laser etching can be effectively removed. Under the joint action of these two aspects, the bonding performance of the substrate and the ceramic coating after the laser pretreatment process is greatly improved, so that it can be effectively applied to workpieces such as power transmission shafts that require higher coating bearing performance, so as to expand the application range of the ceramic coating. The entire process of the laser pretreatment process is completed on a laser processing device, and the process of grinding and degreasing the substrate before laser etching in the existing laser etching pretreatment process is also reduced, shortening the laser pretreatment process flow, saving time cost, and being more conducive to the application of laser pretreatment in engineering practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the surface microscopic morphology of a substrate treated by a laser pretreatment process according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the surface microscopic morphology of a substrate treated by a laser pretreatment process according to a comparative example of the present invention;

[0034] Figure 3 A schematic diagram of the 3D topography of the surface of a substrate treated by a laser pretreatment process according to an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of the 2D topography of the surface of a substrate treated by a laser pretreatment process according to an embodiment of the present invention;

[0036] Figure 5 A schematic diagram of the mass fraction of oxygen element on the surface of a substrate treated by a laser pretreatment process according to an embodiment of the present invention;

[0037] Figure 6 A schematic diagram of the ratio of the surface area of ​​the substrate treated by the laser pretreatment process according to an embodiment of the present invention to the surface area of ​​the original substrate;

[0038] Figure 7A schematic diagram of the bonding strength between the surface of a substrate treated by a laser pretreatment process and a high bonding performance ceramic coating according to an embodiment of the present invention;

[0039] Figure 8 The diagram is a schematic diagram of the shear strength between the surface of a substrate treated by a laser pretreatment process and a high bonding performance ceramic coating according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The descriptions of "first", "second", etc. mentioned in the embodiments of the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0042] In a first aspect of the present invention, a laser pretreatment process is provided, wherein the laser pretreatment process comprises the following steps:

[0043] S1. Cleaning the substrate surface using a laser one-time cleaning process;

[0044] S2, etching the cleaned substrate surface using a laser etching process;

[0045] S3. Use a laser secondary cleaning process to clean the surface of the substrate after etching.

[0046] In the laser pretreatment process described in the present invention, the substrate surface undergoes a laser primary cleaning process → a laser etching process → a laser secondary cleaning process. The laser primary cleaning process, the laser etching process and the laser secondary cleaning process are interrelated and work synergistically. On the one hand, the surface area of ​​the substrate after pretreatment can be more effectively increased; on the other hand, the dirt and oxide layer on the substrate surface before and after laser etching can be effectively removed. Under the combined effect of these two aspects, the bonding performance between the substrate and the ceramic coating after the laser pretreatment process is greatly improved, so that it can be effectively applied to workpieces such as power transmission shafts that require higher coating bearing performance, so as to expand the application range of the ceramic coating. The entire process of the laser pretreatment process is completed on a laser processing device, which effectively reduces the process of grinding and degreasing the substrate before laser etching in the existing laser etching pretreatment process, shortens the laser pretreatment process flow, saves time cost, and is more conducive to the application of laser pretreatment in engineering practice.

[0047] The laser primary cleaning process can effectively remove dirt and oxide layer on the substrate surface before laser etching; the laser etching process can effectively prepare a substrate surface with a high surface area; after the substrate surface is treated by the laser etching process, the substrate surface is oxidized by the high energy of the laser to form a residual oxide layer, and the bonding between the residual oxide layer and the substrate is thermal bonding with low bonding strength. The ceramic coating after spraying will hinder the direct contact between the coating and the substrate due to this layer of oxide and cause the bonding performance to decrease. The laser secondary cleaning process can effectively remove the surface oxide layer and dirt after laser etching to prepare a substrate surface with high cleanliness and high surface area, and the ceramic coating after spraying has better bonding with the substrate; at the same time, the microstructure introduced by the laser secondary cleaning process effectively fills the unprocessed planar area of ​​laser etching, further increasing the surface area of ​​the substrate after pretreatment.

[0048] Specifically, the power of the laser one-time cleaning process is 10-20 W, the frequency is 20 KHz, the scanning speed is 1000 mm / s, the number of scans is 2 times, and the scanning pattern of the laser one-time cleaning process is a first single-line array, and the array interval of the first single-line array is 0.01 mm.

[0049] The parameters of the laser one-time cleaning process are set as above, which can effectively remove the dirt and natural oxide layer on the surface of the substrate before laser etching, and is conducive to etching a better surface of the substrate by the laser etching process.

[0050] Specifically, the laser etching process includes the following steps:

[0051] S21, laser one-time etching process;

[0052] S22, laser secondary etching process;

[0053] S23, laser three-time etching process.

[0054] This setting can effectively prepare a substrate surface with a high surface area, and can more effectively improve the bonding performance between the substrate and the ceramic coating.

[0055] Specifically, the power of the laser one-time etching process is 50-60 W, the frequency is 20 KHz, the scanning speed is 200 mm / s, and the number of scans is 2-4 times. The scanning pattern of the laser one-time etching process is a first three-line combination array, the three-line spacing of the first three-line combination array is 0.02 mm, the array spacing of the first three-line combination array is 0.08-0.14 mm, and the first three-line combination array is perpendicular to the first single-line array.

[0056] The parameters of the laser one-time etching process are within the above range. On the one hand, it can more effectively increase the surface area of ​​the substrate after pretreatment, and the bottom of the prepared surface micro-grooves is sharper, which can form a "chimeric combination" with the coating, thereby more effectively improving the bonding performance of the ceramic coating; on the other hand, the first three-line combination array of the scanning pattern of the laser one-time etching process is perpendicular to the first single-line array of the scanning pattern of the laser one-time cleaning process, which alleviates the stress concentration caused by the single direction and single structure of the microscopic morphology of the substrate surface after pretreatment, thereby more effectively improving the bonding performance of the ceramic coating.

[0057] Specifically, the power of the laser secondary etching process is 40-60 W, the frequency is 20 KHz, the scanning speed is 1000 mm / s, and the number of scans is 2 times. The scanning pattern of the laser secondary etching process is a second three-line combination array, the three-line spacing of the second three-line combination array is 0.02 mm, the array spacing of the second three-line combination array is 0.08-0.14 mm, and the second three-line combination array is perpendicular to the scanning pattern of the first single-line array.

[0058] The parameters of the laser secondary etching process are within the above range. On the one hand, it can more effectively increase the surface area of ​​the substrate after pretreatment, and the bottom of the prepared surface micro-grooves is sharper, which can form a "chimeric combination" with the coating, thereby more effectively improving the bonding performance of the ceramic coating; on the other hand, the second three-line combination array of the scanning pattern of the laser secondary etching process is perpendicular to the first single-line array of the scanning pattern of the laser primary cleaning process, which alleviates the stress concentration caused by the single direction and single structure of the microscopic morphology of the substrate surface after pretreatment, thereby more effectively improving the bonding performance of the ceramic coating.

[0059] Specifically, the power of the three-time laser etching process is 40W, the frequency is 20KHz, the scanning speed is 1000mm / s, and the number of scans is 2 times. The scanning pattern of the three-time laser etching process is a third three-line combination array. The three-line interval of the third three-line combination array is 0.02mm, and the array interval of the third three-line combination array is 0.08-0.14mm. The third three-line combination array is perpendicular to the scanning pattern of the first single-line array.

[0060] The parameters of the three-time laser etching process are within the above range. On the one hand, it can more effectively increase the surface area of ​​the substrate after pretreatment, and the bottom of the prepared surface micro-grooves is sharper, which can form a "chimeric combination" with the coating, thereby more effectively improving the bonding performance of the ceramic coating; on the other hand, the third three-line combination array of the scanning pattern of the three-time laser etching process is perpendicular to the scanning pattern of the first single-line array of the scanning pattern of the one-time laser cleaning process, which alleviates the stress concentration caused by the single direction and single structure of the microscopic morphology of the substrate surface after pretreatment, and can more effectively improve the bonding performance of the ceramic coating.

[0061] Specifically, the power of the laser secondary cleaning process is 10-20 W, the frequency is 20 KHz, the scanning speed is 1000 mm / s, and the number of scans is 2 times. The scanning pattern of the laser secondary cleaning process is a second single-line array, and the second single-line array is perpendicular to the first three-line combination array, the second three-line combination array, and the third three-line combination array. The array interval of the second single-line array is 0.01 mm.

[0062] The parameters of the laser secondary cleaning process are within the above range. First, it can effectively remove the surface oxide layer after laser etching to prepare a substrate surface with high cleanliness and high surface area, and the ceramic coating after spraying is better bonded to the substrate; second, the microstructure introduced by the laser secondary cleaning process effectively fills the unprocessed planar area of ​​the laser etching, further increasing the surface area of ​​the substrate after pretreatment; third, the second single-line array of the scanning pattern of the laser secondary cleaning process is perpendicular to the first three-line combination array, the second three-line combination array, and the third three-line combination array, which alleviates the stress concentration caused by the single direction and single structure of the microscopic morphology of the substrate surface after pretreatment, and can more effectively improve the bonding performance of the ceramic coating.

[0063] The second aspect of the present invention proposes a preparation process of a high-bonding performance ceramic coating, which comprises the following steps: firstly pretreating the surface of the substrate using any one of the laser pretreatment processes described, and then spraying the pretreated substrate using a plasma spraying process to obtain a high-bonding performance ceramic coating.

[0064] Specifically, the process of spraying the pretreated substrate through a plasma spraying process to obtain a high-bonding performance ceramic coating includes the following steps: first, spraying the pretreated substrate through a plasma primary spraying process to obtain a spray base layer, and then spraying the spray base layer through a plasma secondary spraying process to obtain a ceramic layer.

[0065] Specifically, when the pretreated substrate is sprayed by a plasma primary spraying process, the spraying power is 40-70W, the spraying current is 750-800A, the spraying distance is 100mm, the coating powder is Ni20Cr, and the powder particle size is 20-50um.

[0066] Specifically, when the spraying bottom layer is sprayed by the plasma secondary spraying process, the spraying power is 40-70W, the spraying current is 750-800A, the spraying distance is 100mm, the coating powder is Al2O3-13%TiO2, and the powder particle size is 20-50um.

[0067] According to a third aspect of the present invention, a high bonding performance ceramic coating is provided, wherein the high bonding performance ceramic coating is prepared using any one of the processes for preparing the high bonding performance ceramic coating.

[0068] Example 1

[0069] In a first aspect of the present embodiment, a laser pretreatment process is proposed. The thermal spray laser pretreatment process for preparing a high bonding performance ceramic coating comprises the following steps:

[0070] S1. Cleaning the substrate surface using a laser one-time cleaning process;

[0071] S2, etching the cleaned substrate surface using a laser etching process;

[0072] S3. Use a laser secondary cleaning process to clean the surface of the substrate after etching.

[0073] Specifically, the power of the laser one-time cleaning process is 10W, the frequency is 20KHz, the scanning speed is 1000mm / s, the number of scans is 2 times, and the scanning pattern of the laser one-time cleaning process is a first single-line array, and the array interval of the first single-line array is 0.01mm.

[0074] Specifically, the laser etching process includes the following steps:

[0075] S21, laser one-time etching process;

[0076] S22, laser secondary etching process;

[0077] S23, laser three-time etching process.

[0078] Specifically, the power of the laser one-time etching process is 50 W, the frequency is 20 KHz, the scanning speed is 200 mm / s, and the number of scans is 2 times. The scanning pattern of the laser one-time etching process is a first three-line combination array, the three-line spacing of the first three-line combination array is 0.02 mm, the array spacing of the first three-line combination array is 0.14 mm, and the first three-line combination array is perpendicular to the first single-line array.

[0079] Specifically, the power of the laser secondary etching process is 40 W, the frequency is 20 kHz, the scanning speed is 1000 mm / s, and the number of scans is 2 times. The scanning pattern of the laser secondary etching process is a second three-line combination array. The three-line spacing of the second three-line combination array is 0.02 mm, and the array spacing of the second three-line combination array is 0.14 mm. The second three-line combination array is perpendicular to the scanning pattern of the first single-line array.

[0080] Specifically, the power of the three-time laser etching process is 40 W, the frequency is 20 KHz, the scanning speed is 1000 mm / s, and the number of scans is 2 times. The scanning pattern of the three-time laser etching process is a third three-line combination array. The three-line interval of the third three-line combination array is 0.02 mm, and the array interval of the third three-line combination array is 0.14 mm. The third three-line combination array is perpendicular to the scanning pattern of the first single-line array.

[0081] Specifically, the power of the laser secondary cleaning process is 10W, the frequency is 20KHz, the scanning speed is 1000mm / s, and the number of scans is 2 times. The scanning pattern of the laser secondary cleaning process is a second single-line array, and the second single-line array is perpendicular to the first three-line combination array, the second three-line combination array, and the third three-line combination array. The array interval of the second single-line array is 0.01mm.

[0082] The second aspect of this embodiment proposes a preparation process of a high-bonding performance ceramic coating, and the preparation process of the high-bonding performance ceramic coating includes the following steps: first use any one of the laser pretreatment processes described to pretreat the surface of the substrate, and then spray the pretreated substrate through a plasma spraying process to obtain a high-bonding performance ceramic coating.

[0083] Specifically, the process of spraying the pretreated substrate through a plasma spraying process to obtain a high-bonding performance ceramic coating includes the following steps: first, spraying the pretreated substrate through a plasma primary spraying process to obtain a spray base layer, and then spraying the spray base layer through a plasma secondary spraying process to obtain a ceramic layer.

[0084] Specifically, when the pretreated substrate is sprayed by a plasma primary spraying process, the spraying power is 40W, the spraying current is 750A, the spraying distance is 100mm, the coating powder is Ni20Cr, and the powder particle size is 20-50um.

[0085] Specifically, when the spraying bottom layer is sprayed by the plasma secondary spraying process, the spraying power is 40W, the spraying current is 750A, the spraying distance is 100mm, the coating powder is Al2O3-13%TiO2, and the powder particle size is 20-50um.

[0086] In a third aspect of this embodiment, a high bonding performance ceramic coating is provided, wherein the high bonding performance ceramic coating uses any one of the preparation processes of the high bonding performance ceramic coating described above.

[0087] Example 2

[0088] Different from Example 1, in this embodiment, the power of the laser one-time cleaning process is 15W.

[0089] In step S21, in a laser etching process, the scanning pattern is scanned three times.

[0090] In step S22, the power of the laser secondary etching process is 50W.

[0091] The power of the laser secondary cleaning process is 15W.

[0092] Specifically, when the pretreated substrate is sprayed by a plasma primary spraying process, the spraying power is 50W and the spraying current is 760A.

[0093] Specifically, when the spray bottom layer is sprayed by the plasma secondary spraying process, the spraying power is 50W and the spraying current is 760A.

[0094] Example 3

[0095] Different from Example 1, in this embodiment, the power of the laser one-time cleaning process is 20W.

[0096] In step S21 , in the laser one-time etching process, the power of the laser one-time etching process is 60 W. In step S21 , the number of times of scanning the pattern in the laser one-time etching process is 4 times.

[0097] In step S22, the power of the laser secondary etching process is 60W.

[0098] The power of the laser secondary cleaning process is 20W.

[0099] Specifically, when the pretreated substrate is sprayed by a plasma primary spraying process, the spraying power is 55W and the spraying current is 775A.

[0100] Specifically, when the spray base layer is sprayed by the plasma secondary spraying process, the spraying power is 55W and the spraying current is 775A.

[0101] Example 4

[0102] Different from Example 1, in this embodiment, in step S21, the scanning pattern is scanned three times in the laser primary etching process, and the array spacing of the first three-line combination array is 0.12 mm; in step S22, the power of the laser secondary etching process is 50 W, and the array spacing of the second three-line combination array is 0.11 mm; in step S23, the array spacing of the third three-line combination array is 0.11 mm.

[0103] Specifically, when the pretreated substrate is sprayed by a plasma primary spraying process, the spraying power is 60W and the spraying current is 790A.

[0104] Specifically, when the spray base layer is sprayed by the plasma secondary spraying process, the spraying power is 60W and the spraying current is 790A.

[0105] Example 5

[0106] Different from Example 1, in this embodiment, in step S21, the scanning pattern is scanned three times in the laser primary etching process, and the array spacing of the first three-line combination array is 0.09 mm; in step S22, the power of the laser secondary etching process is 50 W, and the array spacing of the second three-line combination array is 0.08 mm; in step S23, the array spacing of the third three-line combination array is 0.08 mm.

[0107] Specifically, when the pretreated substrate is sprayed by a plasma primary spraying process, the spraying power is 70W and the spraying current is 800A.

[0108] Specifically, when the spray base layer is sprayed by the plasma secondary spraying process, the spraying power is 70W and the spraying current is 800A.

[0109] Comparative Example 1

[0110] Different from Example 2, in this comparative example, step S1 is not included.

[0111] Comparative Example 2

[0112] Different from Example 2, in this comparative example, step S2 is not included.

[0113] Comparative Example 3

[0114] Different from Example 2, in this comparative example, step S3 is not included.

[0115] Comparative Example 4

[0116] Different from Example 2, in this comparative example, steps S1, S2 and S3 are not included.

[0117] Comparative Example 5

[0118] Different from Example 2, in this comparative example, the sandblasting method described in Example 1 in the specification of the patent with application number CN201810840858.7 and name "A sandblasting process suitable for plasma spraying" in the background technology is used to pretreat the surface of the substrate.

[0119] Test Example 1: Morphology Characterization

[0120] The surface morphology and elemental composition of the substrate treated by the laser pretreatment process in Example 1 were characterized by SEM and EDS. The test results are as follows: Figure 1 , Figure 3 , Figure 4 , Figure 5 , as shown in Table 1 and Table 2.

[0121] The surface morphology of the substrate treated by the laser pretreatment process in Comparative Example 3 was characterized by SEM. The test results are as follows: Figure 2 shown.

[0122] The surface morphology and surface area of ​​the substrates after pretreatment in Examples 1 to 5 and Comparative Examples 1 to 5 were tested using a laser 3D microscope. The test results are as follows: Figure 6 And as shown in Table 2. Wherein, S = surface area of ​​the substrate after pretreatment / surface area of ​​the original substrate, the unit is %.

[0123] Table 1

[0124] Depth of vertical groove texture (um) Array spacing of vertical groove texture (um) Example 1 60 140 Example 2 90 140 Example 3 120 140 Example 4 90 110 Example 5 90 80

[0125] Table 2

[0126] Oxygen mass fraction (wt%) S(％) Example 1 4.4 185.6 Example 2 4.4 205.0 Example 3 4.6 214.4 Example 4 4.7 208.8 Example 5 4.7 210.9 Comparative Example 1 4.9 178.5 Comparative Example 2 4.6 127.4 Comparative Example 3 12.7 182.5 Comparative Example 4 6.9 100 Comparative Example 5 4.3 171.5

[0127] It can be seen from Table 1 that the depth range of the vertical groove texture on the surface of the substrate treated by the laser pretreatment process in Examples 1 to 5 is 60 to 120um, and the array spacing range of the vertical groove texture on the surface of the substrate treated by the laser pretreatment process in Examples 1 to 5 is 80 to 140um. It should be noted that the main innovation of this patent is laser primary cleaning → laser etching → laser secondary cleaning, and laser etching is divided into 3 steps. In addition to the process parameters specified in the present invention, this process uses lasers according to similar pretreatment steps to obtain the same pattern (the depth range of the vertical groove texture is 60 to 120um, and the array spacing range of the vertical groove texture is 80 to 140um) The laser pretreatment method is also within the scope of protection of this patent.

[0128] from Figure 1 It can be seen that there is an obvious rough surface between two adjacent etched grooves on the substrate surface of Example 1 and there is no black oxidation area or accumulation of dirt, and the substrate surface has high cleanliness and high surface area.

[0129] from Figure 3 and Figure 4 It can be seen that the height of the grooves etched on the surface of the substrate in Example 1 is uniform.

[0130] from Figure 2 It can be seen that there is a black oxidation area and dirt accumulation between two adjacent etching grooves on the surface of the substrate in Comparative Example 3.

[0131] from Figure 5 As can be seen from Table 2, the oxygen element mass fraction on the surface of the substrate treated by the laser pretreatment process in Examples 1 to 5 is relatively low, with the highest being 4.7wt%. The oxygen element mass fraction on the surface of the substrate treated by the laser pretreatment process in Comparative Example 3 is as high as 12.7wt%, which indicates that the laser secondary cleaning process in Examples 1 to 5 effectively removes the oxide layer generated after laser etching.

[0132] Depend on Figure 6 It can be seen from Tables 1 and 2 that as the depth of the etched vertical groove texture on the substrate surface increases, the surface area of ​​the substrate after pretreatment continues to increase; as the array spacing of the etched vertical groove texture on the substrate surface decreases, the surface area of ​​the substrate after pretreatment first increases and then remains basically unchanged.

[0133] Test Example 2: Bonding Strength and Shear Strength Test

[0134] The tensile bonding strength and shear strength of the ceramic coatings prepared in Examples 1 to 5 and Comparative Examples 1 to 5 were tested using an INSTRON 5587 300 kN universal mechanical testing machine. The test standards were GB / T8642 "Determination of tensile bonding strength of thermal spray coatings" and HB 5474 "Test method for shear strength of thermal spray coatings". The test results are shown in Figure 2. Figure 7 , Figure 8 As shown in Table 3;

[0135] Table 3

[0136]

[0137]

[0138] Depend on Figure 7 , Figure 8 From Table 3, we can see that

[0139] (1) The tensile bonding strength and shear strength of the ceramic coatings prepared in Examples 1 to 5 and the substrate are improved compared with those in Comparative Examples 1 to 5. This shows that the laser primary cleaning process, the laser etching process and the laser secondary cleaning process are interrelated and synergistic. On the one hand, the surface area of ​​the substrate after pretreatment can be more effectively increased; on the other hand, the dirt and oxide layer on the surface before and after laser etching can be effectively removed. Under the joint action of these two aspects, the bonding performance between the substrate and the ceramic coating after the laser pretreatment process is greatly improved, so that it can be effectively applied to workpieces such as power transmission shafts that require higher coating bearing performance, so as to expand the application range of the ceramic coating.

[0140] (2) In Examples 1 to 5, when the array spacing of the etched vertical groove texture on the substrate surface is the same, the coating bonding strength first increases and then decreases with the increase in the depth of the etched vertical groove texture on the substrate surface. When the depth is 90um, the coating bonding strength is the highest, which is 43.4MPa. The coating shear strength increases continuously with the increase in depth. When the depth is ≥90um, the coating shear strength increases weakly.

[0141] (3) In Examples 1 to 5, when the depth of the etched vertical groove texture on the substrate surface is the same, when the array spacing of the etched vertical groove texture on the substrate surface is less than 140um, the coating bonding strength increases slightly with the decrease in the spacing and remains basically unchanged; the shear strength continues to increase with the decrease in the array spacing of the etched vertical groove texture on the substrate surface.

[0142] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A laser pretreatment process, characterized in that: The laser pretreatment process is used to prepare a high-bonding performance ceramic coating, and the laser pretreatment process comprises the following steps: S1. Cleaning the substrate surface using a laser one-time cleaning process; S2, etching the cleaned substrate surface using a laser etching process; S3, using a laser secondary cleaning process to clean the surface of the substrate after etching; In step S1, the power of the laser one-time cleaning process is 10-20 W, the frequency is 20 kHz, the scanning speed is 1000 mm / s, the number of scanning times is 2 times, and the scanning pattern of the laser one-time cleaning process is a first single-line array, and the array interval of the first single-line array is 0.01 mm; In step S2, the laser etching process includes the following steps: S21, laser one-time etching process; S22, laser secondary etching process; S23, laser three-time etching process; In step S21, the power of the laser one-time etching process is 50-60 W, the frequency is 20 kHz, the scanning speed is 200 mm / s, the number of scanning times is 2-4 times, the scanning pattern of the laser one-time etching process is a first three-line combination array, the three-line interval of the first three-line combination array is 0.02 mm, the array interval of the first three-line combination array is 0.08-0.14 mm, and the first three-line combination array is perpendicular to the first single-line array; In step S22, the power of the laser secondary etching process is 40-60 W, the frequency is 20 kHz, the scanning speed is 1000 mm / s, the number of scans is 2 times, the scanning pattern of the laser secondary etching process is a second three-line combination array, the three-line interval of the second three-line combination array is 0.02 mm, the array interval of the second three-line combination array is 0.08-0.14 mm, and the second three-line combination array is perpendicular to the first single-line array; In step S23, the power of the three-time laser etching process is 40W, the frequency is 20kHz, the scanning speed is 1000mm / s, the number of scans is 2 times, the scanning pattern of the three-time laser etching process is a third three-line combination array, the three-line interval of the third three-line combination array is 0.02mm, the array interval of the third three-line combination array is 0.08-0.14mm, and the third three-line combination array is perpendicular to the first single-line array; In step S3, the power of the laser secondary cleaning process is 10~20W, the frequency is 20kHz, the scanning speed is 1000mm / s, and the number of scans is 2 times. The scanning pattern of the laser secondary cleaning process is a second single-line array, and the second single-line array is perpendicular to the first three-line combination array, the second three-line combination array, and the third three-line combination array. The array interval of the second single-line array is 0.01mm.

2. A process for preparing a high bonding performance ceramic coating, characterized in that: The preparation process of the high-bonding performance ceramic coating comprises the following steps: firstly pre-treating the surface of the substrate by a laser pre-treatment process as described in claim 1, and then spraying the pre-treated substrate by a plasma spraying process to obtain the high-bonding performance ceramic coating; The process of spraying the pretreated substrate by a plasma spraying process to obtain a high-bonding performance ceramic coating comprises the following steps: firstly spraying the pretreated substrate by a plasma primary spraying process to obtain a spraying bottom layer, and then spraying the spraying bottom layer by a plasma secondary spraying process to obtain a ceramic layer; When the pretreated substrate is sprayed by the plasma primary spraying process, the spraying power is 40-70W, the spraying current is 750-800A, the spraying distance is 100mm, the coating powder is Ni20Cr, and the powder particle size is 20-50um; when the spray base layer is sprayed by the plasma secondary spraying process, the spraying power is 40-70W, the spraying current is 750-800A, the spraying distance is 100mm, the coating powder is Al2O3-13%TiO2, and the powder particle size is 20-50um.

3. A high bonding performance ceramic coating, characterized in that: The high bonding performance ceramic coating uses the preparation process of the high bonding performance ceramic coating described in claim 2.

Images