A composite high-energy beam pretreatment method for repairing thermal sprayed metal coatings

Abstract

A composite high-energy beam pretreatment method for repairing thermal spraying metal coating belongs to the field of material science and processing technology, and the steps are as follows: obtaining the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be treated, adjusting the working parameters of the continuous laser, cleaning the damaged area of the metal coating to remove the damaged coating; according to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted, and the residual damaged coating is removed by using the nanosecond laser, and the treated workpiece is obtained after laser treatment and cleaning. The present application adopts laser as a pretreatment means, realizes the selective removal of the metal coating with micron-level precision, is especially suitable for the local repair of high bonding strength materials such as nickel-based coating, and can completely retain the surrounding intact coating and substrate material; the treatment process almost does not produce dust and chemical waste, and through parameter optimization, an active oxide layer beneficial to the combination of the new coating can be induced on the surface.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of material science and processing technology, and particularly relates to a composite high-energy beam pretreatment method for repairing thermal spraying metal coating. BACKGROUND

[0002] Nickel-based alloy is an ideal choice for marine environment protection due to its unique material properties. Its excellent corrosion resistance is derived from the good passivation ability of nickel itself, which can form a dense oxide film in the presence of chloride ions, effectively blocking the corrosion of corrosive media. Compared with ordinary carbon steel, the corrosion rate of nickel-based alloy can be reduced by two orders of magnitude, which makes it irreplaceable in the field of marine equipment protection. From the material composition, nickel-based alloy can be optimized by adjusting the proportion of alloying elements such as chromium, molybdenum, and copper, according to different marine environments. For example, the addition of 15% to 20% chromium can significantly improve the pitting corrosion resistance of the alloy, the addition of molybdenum can enhance the resistance to crevice corrosion, and the addition of copper can improve the stability of the alloy in deep-sea high-pressure environment. This composition adjustability enables nickel-based coating to adapt to various marine environments from the intertidal zone to the deep sea, exhibiting excellent environmental adaptability.

[0003] In practical engineering applications, thermal spraying nickel-based metal coating has shown excellent protective performance: the service life of a marine wind turbine foundation pile in the splash zone is extended from 10 years to more than 25 years after the application of nickel-chromium alloy coating; the wear resistance of a marine oil and gas Christmas tree valve surface is improved by 5 times after spraying nickel-based alloy, significantly reducing maintenance frequency; the application of nickel-aluminum bronze coating to the propeller shaft of a ship not only improves the cavitation erosion resistance, but also effectively solves the problem of galvanic corrosion. However, as the service time increases, the coating inevitably suffers local peeling, micro-cracks and other damages, which will accelerate the corrosion of the substrate and even cause structural failure if not repaired in time. The current repair process requires the removal of damaged coating, but the high bonding force (usually > 30 MPa) between nickel-based coating and substrate makes traditional sandblasting difficult: on the one hand, high-speed abrasive impact can effectively remove the oxide layer, but it will generate a large amount of dust pollution; on the other hand, excessive sandblasting may lead to uncontrollable surface roughness of the substrate, affecting the bonding performance of the new coating. Therefore, for high-melting-point, high-bonding-force metal coatings and metal composite coatings, a new pretreatment technology that takes into account environmental friendliness and efficiency is urgently needed, which should meet the following requirements: (1) accurately remove the failed coating without damaging the substrate; (2) the treatment process should have no pollution emissions; (3) it should create the best surface activity for re-spraying. The breakthrough of this technology will significantly improve the maintenance efficiency of nickel-based coating throughout its life cycle. SUMMARY

[0004] In view of the deficiencies of the prior art, the application provides a composite high-energy beam pretreatment method for repairing thermal spraying metal coating, which solves the technical problem of laser removal of metal coating, can efficiently and high-quality remove the metal coating, simultaneously activates the metal surface, meets the removal and substrate activation targets, simplifies the metal coating repair process, and saves time and cost.

[0005] A composite high-energy beam pretreatment method for repairing thermal spraying metal coating, specifically comprising the following steps:

[0006] Step 1: obtaining the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be treated, placing the workpiece to be treated directly below the laser head of the continuous laser, keeping the workpiece to be treated parallel to the platform surface of the continuous laser, adjusting the working parameters of the continuous laser, adjusting the laser focus so that the laser energy generated by the continuous laser is concentrated in the damaged area of the metal coating, and the working parameters of the continuous laser include laser power, laser pulse frequency and laser wavelength;

[0007] Step 2: cleaning the damaged area of the metal coating with the continuous laser to remove the damaged coating; then adjusting the working parameters of the nanosecond laser according to the cleaning result of the continuous laser, adjusting the laser focus so that the laser energy generated by the nanosecond laser is concentrated in the metal coating removal area, and cleaning with the nanosecond laser to remove the residual damaged coating; the workpiece after laser treatment is cooled to room temperature in the air, and the treated workpiece is obtained after cleaning the surface;

[0008] The working parameters of the nanosecond laser include laser power, laser pulse width, laser wavelength and laser pulse frequency;

[0009] The continuous laser and the nanosecond laser form laser spots by pulsed laser to remove the damaged coating by inducing plume, and the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece during the cleaning process;

[0010] The continuous laser immerses the metal coating in water when cleaning the damaged area, and the cleaning area of the nanosecond laser is the coating area treated by the continuous laser.

[0011] Wherein:

[0012] In step 1, the material of the metal coating is nickel-based or iron-based, and the bonding strength of the metal coating is greater than 30MPa.

[0013] In step 1, the thickness of the metal coating is 200μm~1000μm.

[0014] In the step 1, the laser power of the continuous laser is 750W-1050W, the laser pulse frequency is 30kHz, and the laser wavelength is 1064nm.

[0015] In the step 2, the laser power of the nanosecond pulse laser is 40W-60W, the laser pulse width is 10ns, the laser wavelength is 1064nm, and the laser pulse frequency is 2500kHz.

[0016] In the step 2, the laser scanning interval of the continuous laser is greater than the diameter of the laser spot, and the laser scanning interval of the nanosecond laser is less than the diameter of the laser spot.

[0017] In the step 2, the metal coating is immersed in water by 2mm-3mm.

[0018] Compared with the prior art, the beneficial effects of the present application are:

[0019] 1. The present application realizes multi-dimensional accurate control of the cleaning process by precisely regulating the core parameters such as laser power and pulse frequency in the laser cleaning process. In the cleaning process, the energy input is dynamically adjusted according to the coating thickness and substrate characteristics, and on the premise of ensuring the complete removal of the metal coating, the intelligent matching of the energy gradient effectively avoids the risk of excessive cleaning of the substrate material. Especially for super-thick metal coatings or composite coating systems, the layered peeling strategy is innovatively adopted - high-efficiency and high-precision removal of metal coatings is implemented by high-power continuous laser and low-power nanosecond laser. This composite laser progressive cleaning method can completely remove the target coating while controlling the substrate heat affected zone and surface roughness, providing an ideal surface state for subsequent remanufacturing processes, reducing the metal surface activation link, improving the construction efficiency, and saving costs.

[0020] 2. The present application uses laser as a pretreatment means to realize the selective removal of metal coatings with micron-level precision, especially suitable for local repair of high-bond-strength materials such as nickel-based coatings, and can completely retain the surrounding intact coating and substrate material; the processing process almost does not produce dust and chemical waste, meeting the requirements of ISO 14001 environmental management system; in addition, parameter optimization can induce the formation of an active oxide layer on the surface which is beneficial to the bonding of the new coating. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 In the embodiment 1 of the present application, the macroscopic morphology diagram of the metal coating after being treated by the continuous laser and then treated by the nanosecond laser;

[0022] Figure 2 In the embodiment 4 of the present application, the macroscopic morphology diagram of the metal coating after being treated by the continuous laser and then treated by the nanosecond laser;

[0023] Figure 3A macroscopic topography diagram of the metal coating in Example 9 of the present application after being treated by a continuous laser and then treated by a nanosecond laser. DETAILED DESCRIPTION

[0024] The specific embodiments of the present application are described in further detail below in conjunction with the accompanying drawings and examples.

[0025] A composite high-energy beam pretreatment method for repairing thermal spraying metal coating, specifically comprising the following steps:

[0026] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be treated, place the workpiece to be treated directly below the laser head of the continuous laser, keep the workpiece to be treated parallel to the platform surface of the continuous laser, and adjust the working parameters of the continuous laser: the laser power of the continuous laser is 750W-1050W, the laser pulse frequency is 30kHz, the laser wavelength is 1064nm, and the laser focusing is adjusted so that the laser energy generated by the continuous laser is concentrated in the damaged area of the metal coating.

[0027] In the present application, the material of the metal coating is nickel-based or iron-based, the bonding strength of the metal coating is greater than 30MPa, and the thickness of the metal coating is 200μm-1000μm.

[0028] Step 2: immerse the metal coating in water by 2mm-3mm, use the continuous laser to clean the damaged area of the metal coating, remove the damaged coating, and the laser scanning interval of the continuous laser is greater than the diameter of the laser spot; then adjust the working parameters of the nanosecond laser according to the cleaning result of the continuous laser, the laser power of the nanosecond laser is 40W-60W, the laser pulse width is 10ns, the laser wavelength is 1064nm, the laser pulse frequency is 2500kHz, the laser focusing is adjusted so that the laser energy generated by the nanosecond laser is concentrated in the metal coating removal area, and the nanosecond laser is used for cleaning to remove the residual damaged coating, the cleaning area is the coating area treated by the continuous laser, and the laser scanning interval of the nanosecond laser is less than the diameter of the laser spot. The continuous laser and the nanosecond laser form a laser spot by pulsed laser to induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece. After laser treatment, the workpiece is cooled to room temperature in air, and the treated workpiece is obtained after cleaning the surface.

[0029] In the present application, the workpiece sample to be treated is prepared by thermal spraying metal wire material on a 45# steel plate, and then cooled and cleaned in air to obtain the metal coating.

[0030] Example 1

[0031] A composite high-energy beam pretreatment method for repairing thermal spraying metal coating, specifically comprising the following steps:

[0032] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be processed: the substrate is a 45# steel plate, the metal coating is iron-based, the bonding strength of the metal coating is > 30 MPa, and the thickness is 200 μm. The workpiece to be processed is placed directly below the continuous laser head, keeping the workpiece to be processed parallel to the platform surface of the continuous laser, and adjusting the working parameters of the continuous laser: the laser power of the continuous laser is 750 W, the laser pulse frequency is 30 kHz, the laser wavelength is 1064 nm, and the laser focusing is adjusted to concentrate the laser energy generated by the continuous laser on the damaged area of the metal coating.

[0033] Step 2: immerse the metal coating in water by 2 mm, use a high-power continuous laser to clean the damaged area of the metal coating, remove the damaged coating, the diameter of the laser spot of the continuous laser is 100 μm, the laser scanning interval is 1 mm, the laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 1 mm / s, and the scanning times is 1.

[0034] According to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted: the laser power of the nanosecond laser is 40 W, the laser pulse width is 10 ns, the laser wavelength is 1064 nm, and the laser pulse frequency is 2500 kHz. Adjust the laser focusing to concentrate the laser energy generated by the nanosecond laser on the metal coating removal area, use a low-power nanosecond laser to clean, remove the residual damaged coating, and the cleaning area is the coating area treated by the continuous laser. The diameter of the laser spot of the nanosecond laser is 70 μm, the laser spot overlap rate is 65%~75%, and the laser scanning interval is 0.010 mm. The laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 15 mm / s, and the scanning times is 1. The continuous laser and the nanosecond laser form a laser spot by pulsed laser, and induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece.

[0035] After laser treatment, the treated workpiece is cooled to room temperature in air, and the workpiece surface is cleaned with a brush to obtain the treated workpiece, and the macroscopic morphology of the treated workpiece is shown in Figure 1 After the nanosecond laser treatment, the workpiece surface can not only remove the residual coating, but also activate the metal substrate surface, which can be directly used for thermal spraying.

[0036] Example 2

[0037] A composite high-energy beam pretreatment method for repairing thermal sprayed metal coating, specifically comprising the following steps:

[0038] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be processed: the substrate is a 45# steel plate, the metal coating is iron-based, the bonding strength of the metal coating is > 30 MPa, and the thickness is 250 μm. The workpiece to be processed is placed directly below the continuous laser head, the workpiece to be processed is kept parallel to the platform surface of the continuous laser, and the working parameters of the continuous laser are adjusted: the laser power of the continuous laser is 770 W, the laser pulse frequency is 30 kHz, the laser wavelength is 1064 nm, and the laser focusing is adjusted to concentrate the laser energy generated by the continuous laser on the damaged area of the metal coating.

[0039] Step 2: immerse the metal coating in water by 2 mm, use a high-power continuous laser to clean the damaged area of the metal coating, remove the damaged coating, the diameter of the laser spot of the continuous laser is 100 μm, the laser scanning interval is 1 mm, the laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 1 mm / s, and the scanning times is 1.

[0040] According to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted: the laser power of the nanosecond laser is 42 W, the laser pulse width is 10 ns, the laser wavelength is 1064 nm, and the laser pulse frequency is 2500 kHz. Adjust the laser focusing to concentrate the laser energy generated by the nanosecond laser on the metal coating removal area, use a low-power nanosecond laser to clean and remove the residual damaged coating, and the cleaning area is the coating area treated by the continuous laser. The diameter of the laser spot of the nanosecond laser is 70 μm, the laser spot overlap rate is 65%~75%, and the laser scanning interval is 0.010 mm. The laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 15 mm / s, and the scanning times is 1. The continuous laser and the nanosecond laser form a laser spot by pulse laser, and induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece.

[0041] After the laser treatment is completed, the treated workpiece is cooled to room temperature in the air, and then the workpiece surface is cleaned with a brush to obtain the treated workpiece. After the nanosecond laser treatment, the workpiece surface can not only remove the residual coating, but also activate the metal substrate surface, which can be directly used for thermal spraying.

[0042] Example 3

[0043] A composite high-energy beam pretreatment method for repairing thermal sprayed metal coating, specifically comprising the following steps:

[0044] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be processed: the substrate is a 45# steel plate, the metal coating is iron-based, the bonding strength of the metal coating is > 30 MPa, and the thickness is 300 μm. The workpiece to be processed is placed directly below the continuous laser head, the workpiece to be processed is kept parallel to the platform surface of the continuous laser, and the working parameters of the continuous laser are adjusted: the laser power of the continuous laser is 790 W, the laser pulse frequency is 30 kHz, the laser wavelength is 1064 nm, and the laser focusing is adjusted so that the laser energy generated by the continuous laser is concentrated in the damaged area of the metal coating.

[0045] Step 2: immerse the metal coating in water by 2 mm, use a high-power continuous laser to clean the damaged area of the metal coating, remove the damaged coating, the diameter of the laser spot of the continuous laser is 100 μm, the laser scanning interval is 1 mm, the laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 1 mm / s, and the scanning times is 1.

[0046] According to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted: the laser power of the nanosecond laser is 44 W, the laser pulse width is 10 ns, the laser wavelength is 1064 nm, and the laser pulse frequency is 2500 kHz. Adjust the laser focusing so that the laser energy generated by the nanosecond laser is concentrated in the metal coating removal area, use a low-power nanosecond laser to clean, remove the residual damaged coating, and the cleaning area is the coating area treated by the continuous laser. The diameter of the laser spot of the nanosecond laser is 70 μm, the laser spot overlap rate is 65%~75%, and the laser scanning interval is 0.010 mm. The laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 15 mm / s, and the scanning times is 1. The continuous laser and the nanosecond laser form a laser spot by pulse laser, and induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece.

[0047] After the laser treatment is completed, the treated workpiece is cooled to room temperature in the air, and then the workpiece surface is cleaned with a brush to obtain the treated workpiece. After the nanosecond laser treatment, the workpiece surface can not only remove the residual coating, but also activate the metal substrate surface, which can be directly used for thermal spraying.

[0048] Example 4

[0049] A composite high-energy beam pretreatment method for repairing thermal sprayed metal coating, specifically comprising the following steps:

[0050] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be processed: the substrate is a 45# steel plate, the metal coating is iron-based, the bonding strength of the metal coating is > 30 MPa, and the thickness is 600 μm. The workpiece to be processed is placed directly below the continuous laser head, keeping the workpiece parallel to the platform surface of the continuous laser, and adjusting the working parameters of the continuous laser: the laser power of the continuous laser is 900 W, the laser pulse frequency is 30 kHz, the laser wavelength is 1064 nm, and the laser focusing is adjusted to concentrate the laser energy generated by the continuous laser on the damaged area of the metal coating.

[0051] Step 2: Submerge the metal coating in water by 3 mm, use a high-power continuous laser to clean the damaged area of the metal coating, remove the damaged coating, the diameter of the laser spot of the continuous laser is 100 μm, the laser scanning interval is 1 mm, the laser cleaning head uses a "heng" shape scanning path to scan, the scanning speed is 1 mm / s, and the scanning times is 1.

[0052] According to the cleaning results of the continuous laser, adjust the working parameters of the nanosecond laser: the laser power of the nanosecond laser is 50 W, the laser pulse width is 10 ns, the laser wavelength is 1064 nm, and the laser pulse frequency is 2500 kHz. Adjust the laser focusing to concentrate the laser energy generated by the nanosecond laser on the metal coating removal area, use a low-power nanosecond laser to clean, remove the residual damaged coating, and the cleaning area is the coating area processed by the continuous laser. The diameter of the laser spot of the nanosecond laser is 70 μm, the laser spot overlap rate is 65%~75%, and the laser scanning interval is 0.011 mm. The laser cleaning head uses a "heng" shape scanning path to scan, the scanning speed is 15 mm / s, and the scanning times is 1. The continuous laser and the nanosecond laser form a laser spot by pulsed laser, and induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece.

[0053] After laser processing, the processed workpiece is cooled to room temperature in air, and the workpiece surface is cleaned with a brush to obtain the processed workpiece, and the macroscopic morphology of the processed workpiece is shown in Figure 2 After the nanosecond laser processing, the workpiece surface can not only remove the residual coating, but also activate the metal substrate surface, which can be directly used for thermal spraying.

[0054] Example 5

[0055] A composite high-energy beam pretreatment method for repairing thermal sprayed metal coating, specifically comprising the following steps:

[0056] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be processed: the substrate is a 45# steel plate, the metal coating is iron-based, the bonding strength of the metal coating is > 30 MPa, and the thickness is 650 μm. The workpiece to be processed is placed directly below the continuous laser head, the workpiece to be processed is kept parallel to the platform surface of the continuous laser, and the working parameters of the continuous laser are adjusted: the laser power of the continuous laser is 920 W, the laser pulse frequency is 30 kHz, the laser wavelength is 1064 nm, and the laser focusing is adjusted so that the laser energy generated by the continuous laser is concentrated in the damaged area of the metal coating.

[0057] Step 2: immerse the metal coating in water by 3 mm, use a high-power continuous laser to clean the damaged area of the metal coating, remove the damaged coating, the diameter of the laser spot of the continuous laser is 100 μm, the laser scanning interval is 1 mm, the laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 1 mm / s, and the scanning times is 1.

[0058] According to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted: the laser power of the nanosecond laser is 52 W, the laser pulse width is 10 ns, the laser wavelength is 1064 nm, and the laser pulse frequency is 2500 kHz. Adjust the laser focusing so that the laser energy generated by the nanosecond laser is concentrated in the metal coating removal area, use a low-power nanosecond laser to clean, remove the residual damaged coating, and the cleaning area is the coating area treated by the continuous laser. The diameter of the laser spot of the nanosecond laser is 70 μm, the laser spot overlap rate is 65%~75%, and the laser scanning interval is 0.010 mm. The laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 15 mm / s, and the scanning times is 1. The continuous laser and the nanosecond laser form a laser spot by pulsed laser, and induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece.

[0059] After the laser treatment is completed, the treated workpiece is cooled to room temperature in the air, and then the workpiece surface is cleaned with a brush to obtain the treated workpiece. After the nanosecond laser treatment, the workpiece surface can not only remove the residual coating, but also activate the metal substrate surface, which can be directly used for thermal spraying.

[0060] Example 6

[0061] A composite high-energy beam pretreatment method for repairing thermal sprayed metal coating, specifically comprising the following steps:

[0062] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be processed: the substrate is a 45# steel plate, the metal coating is iron-based, the bonding strength of the metal coating is > 30 MPa, and the thickness is 700 μm. The workpiece to be processed is placed directly below the continuous laser head, the workpiece to be processed is kept parallel to the platform surface of the continuous laser, and the working parameters of the continuous laser are adjusted: the laser power of the continuous laser is 940 W, the laser pulse frequency is 30 kHz, the laser wavelength is 1064 nm, and the laser focusing is adjusted so that the laser energy generated by the continuous laser is concentrated in the damaged area of the metal coating.

[0063] Step 2: immerse the metal coating in water by 3 mm, use a high-power continuous laser to clean the damaged area of the metal coating, remove the damaged coating, the diameter of the laser spot of the continuous laser is 100 μm, the laser scanning interval is 1 mm, the laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 1 mm / s, and the scanning times is 1.

[0064] According to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted: the laser power of the nanosecond laser is 54 W, the laser pulse width is 10 ns, the laser wavelength is 1064 nm, and the laser pulse frequency is 2500 kHz. Adjust the laser focusing so that the laser energy generated by the nanosecond laser is concentrated in the metal coating removal area, use a low-power nanosecond laser to clean, remove the residual damaged coating, and the cleaning area is the coating area treated by the continuous laser. The diameter of the laser spot of the nanosecond laser is 70 μm, the laser spot overlap rate is 65%~75%, and the laser scanning interval is 0.010 mm. The laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 15 mm / s, and the scanning times is 1. The continuous laser and the nanosecond laser form a laser spot by pulsed laser, and induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece.

[0065] After the laser treatment is completed, the treated workpiece is cooled to room temperature in the air, and then the workpiece surface is cleaned with a brush to obtain the treated workpiece. After the nanosecond laser treatment, the workpiece surface can not only remove the residual coating, but also activate the metal substrate surface, which can be directly used for thermal spraying.

[0066] Example 7

[0067] A composite high-energy beam pretreatment method for repairing thermal sprayed metal coating, specifically comprising the following steps:

[0068] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be processed: the substrate is a 45# steel plate, the metal coating is iron-based, the bonding strength of the metal coating is > 30 MPa, and the thickness is 900 μm. The workpiece to be processed is placed directly below the continuous laser head, the workpiece to be processed is kept parallel to the platform surface of the continuous laser, and the working parameters of the continuous laser are adjusted: the laser power of the continuous laser is 1000 W, the laser pulse frequency is 30 kHz, the laser wavelength is 1064 nm, and the laser focusing is adjusted to concentrate the laser energy generated by the continuous laser on the damaged area of the metal coating.

[0069] Step 2: immerse the metal coating in water by 3 mm, use a high-power continuous laser to clean the damaged area of the metal coating, remove the damaged coating, the diameter of the laser spot of the continuous laser is 100 μm, the laser scanning interval is 1 mm, the laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 1 mm / s, and the scanning times is 1.

[0070] According to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted: the laser power of the nanosecond laser is 50 W, the laser pulse width is 10 ns, the laser wavelength is 1064 nm, and the laser pulse frequency is 2500 kHz. Adjust the laser focusing to concentrate the laser energy generated by the nanosecond laser on the metal coating removal area, use a low-power nanosecond laser to clean and remove the residual damaged coating, and the cleaning area is the coating area treated by the continuous laser. The diameter of the laser spot of the nanosecond laser is 70 μm, the laser spot overlap rate is 65%~75%, and the laser scanning interval is 0.012 mm. The laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 15 mm / s, and the scanning times is 1. The continuous laser and the nanosecond laser form a laser spot by pulse laser, and induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece.

[0071] After the laser treatment is completed, the treated workpiece is cooled to room temperature in the air, and then the workpiece surface is cleaned with a brush to obtain the treated workpiece. After the nanosecond laser treatment, the workpiece surface can not only remove the residual coating, but also activate the metal substrate surface, which can be directly used for thermal spraying.

[0072] Example 8

[0073] A composite high-energy beam pretreatment method for repairing thermal sprayed metal coating, specifically comprising the following steps:

[0074] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be processed: the substrate is a 45# steel plate, the metal coating is iron-based, the bonding strength of the metal coating is > 30 MPa, and the thickness is 950 μm. The workpiece to be processed is placed directly below the continuous laser head, the workpiece to be processed is kept parallel to the platform surface of the continuous laser, and the working parameters of the continuous laser are adjusted: the laser power of the continuous laser is 1020 W, the laser pulse frequency is 30 kHz, the laser wavelength is 1064 nm, and the laser focusing is adjusted so that the laser energy generated by the continuous laser is concentrated in the damaged area of the metal coating.

[0075] Step 2: immerse the metal coating in water by 3 mm, use a high-power continuous laser to clean the damaged area of the metal coating, remove the damaged coating, the diameter of the laser spot of the continuous laser is 100 μm, the laser scanning interval is 1 mm, the laser cleaning head adopts a "heng" shape scanning path, the scanning speed is 1 mm / s, and the scanning times is 1.

[0076] According to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted: the laser power of the nanosecond laser is 55 W, the laser pulse width is 10 ns, the laser wavelength is 1064 nm, and the laser pulse frequency is 2500 kHz. Adjust the laser focusing so that the laser energy generated by the nanosecond laser is concentrated in the metal coating removal area, use a low-power nanosecond laser to clean, remove the residual damaged coating, and the cleaning area is the coating area treated by the continuous laser. The diameter of the laser spot of the nanosecond laser is 70 μm, the laser spot overlap rate is 65%~75%, and the laser scanning interval is 0.012 mm. The laser cleaning head adopts a "heng" shape scanning path, the scanning speed is 15 mm / s, and the scanning times is 1. The continuous laser and the nanosecond laser form a laser spot by pulse laser, and induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece.

[0077] After laser treatment, the treated workpiece is cooled to room temperature in air, and the workpiece surface is cleaned with a brush to obtain the treated workpiece. After the nanosecond laser treatment, the workpiece surface can not only remove the residual coating, but also activate the metal substrate surface, which can be directly used for thermal spraying.

[0078] Example 9

[0079] A composite high-energy beam pretreatment method for repairing thermal sprayed metal coating, specifically comprising the following steps:

[0080] Step 1: Obtain the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be processed: the substrate is a 45# steel plate, the material of the metal coating is iron-based, the bonding strength of the metal coating is > 30 MPa, and the thickness is 1000 μm. The workpiece to be processed is placed directly below the continuous laser head, the workpiece to be processed is kept parallel to the platform surface of the continuous laser, and the working parameters of the continuous laser are adjusted: the laser power of the continuous laser is 1050 W, the laser pulse frequency is 30 kHz, the laser wavelength is 1064 nm, and the laser focusing is adjusted so that the laser energy generated by the continuous laser is concentrated in the damaged area of the metal coating.

[0081] Step 2: immerse the metal coating in water by 3 mm, use a high-power continuous laser to clean the damaged area of the metal coating, remove the damaged coating, the diameter of the laser spot of the continuous laser is 100 μm, the laser scanning interval is 1 mm, the laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 1 mm / s, and the scanning times is 1.

[0082] According to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted: the laser power of the nanosecond laser is 60 W, the laser pulse width is 10 ns, the laser wavelength is 1064 nm, and the laser pulse frequency is 2500 kHz. Adjust the laser focusing so that the laser energy generated by the nanosecond laser is concentrated in the metal coating removal area, use a low-power nanosecond laser to clean, remove the residual damaged coating, and the cleaning area is the coating area processed by the continuous laser. The diameter of the laser spot of the nanosecond laser is 70 μm, the laser spot overlap rate is 65%~75%, and the laser scanning interval is 0.012 mm. The laser cleaning head adopts a "heng" shape scanning path scanning, the scanning speed is 15 mm / s, and the scanning times is 1. The continuous laser and the nanosecond laser form a laser spot by pulsed laser, and induce a plume to remove the damaged coating. During the cleaning process, the energy input is dynamically adjusted according to the coating thickness and the substrate characteristics of the workpiece.

[0083] After the laser treatment is completed, the treated workpiece is cooled to room temperature in the air, and the workpiece surface is cleaned with a brush to obtain a treated workpiece, and a macroscopic morphology diagram of the treated workpiece is shown in Figure 3 After the nanosecond laser treatment, the workpiece surface can remove the residual coating and activate the metal substrate surface, and can be directly used for thermal spraying.

[0084] The protection scope of the present application is not limited to the above-mentioned embodiments, and obviously, those skilled in the art can make various modifications and changes to the present application without departing from the scope and spirit of the present application. If these modifications and changes belong to the scope of the present application and its equivalent technology, the intention of the present application also includes these modifications and changes.

Claims

1. A combined high-energy beam pretreatment method for repairing thermal sprayed metal coatings, characterized in that Specifically comprising the following steps: Step 1: obtaining the coating material, shape and thickness of the damaged area of the metal coating of the workpiece to be treated, placing the workpiece to be treated directly below the continuous laser head, keeping the workpiece to be treated parallel to the platform surface of the continuous laser, adjusting the working parameters of the continuous laser, and adjusting the laser focusing to concentrate the laser energy generated by the continuous laser on the damaged area of the metal coating; The material of the metal coating is nickel-based or iron-based, and the bonding strength of the metal coating is > 30 Mpa. The laser power of the continuous laser is 750W~1050W, the laser pulse frequency is 30kHz, the laser wavelength is 1064nm, the laser scanning interval is 1mm, the laser cleaning head adopts a "H" shaped scanning path, and the scanning speed is 1mm / s; Step 2: cleaning the damaged area of the metal coating with a continuous laser to remove the damaged coating; Then, according to the cleaning result of the continuous laser, the working parameters of the nanosecond laser are adjusted, the laser focusing is adjusted to concentrate the laser energy generated by the nanosecond laser on the metal coating removal area, and the residual damaged coating is removed by cleaning with the nanosecond laser; After the laser treatment, the workpiece is cooled to room temperature in the air, and the treated workpiece is obtained after cleaning the surface; The laser power of the nanosecond laser is 40W~60W, the laser pulse width is 10ns, the laser wavelength is 1064nm, the laser pulse frequency is 2500kHz, the laser scanning interval is 0.010mm, the laser spot overlap rate is 65%~75%, the laser cleaning head adopts a "H" shaped scanning path, and the scanning speed is 15mm / s; The laser scanning interval of the nanosecond laser is less than the diameter of the laser spot. The continuous laser and the nanosecond laser form a laser spot by pulsed laser to remove the damaged coating; When the continuous laser cleans the damaged area, the metal coating is immersed in water; The cleaning area of the nanosecond laser is the coating area treated by the continuous laser.

2. A hybrid high-energy beam pretreatment process for repairing thermal spray metal coatings according to claim 1 wherein, In step 1, the thickness of the metal coating is 200μm~1000μm.

3. A hybrid high-energy beam pretreatment process for repairing thermal spray metal coatings according to claim 1 wherein, In step 2, the laser scanning interval of the continuous laser is greater than the diameter of the laser spot.

4. A hybrid high-energy beam pretreatment process for repairing thermal spray metal coatings according to claim 1 wherein, In step 2, the metal coating is immersed in water 2mm~3mm.

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