A laser cladding powder and a method for laser cladding on an aluminum alloy surface

Abstract

The application provides a laser cladding powder and a method for laser cladding on an aluminum alloy surface, and belongs to the technical field of laser cladding. The laser cladding powder comprises Mo powder, V powder, Al powder, AlB2 powder, CeO2 powder and Ti powder. Since the aluminum alloy substrate and the titanium powder are both non-ferrous metals, the absorption utilization rate of near-infrared light is lower than that of visible light. By adopting a composite light beam composed of blue light and near-infrared light for cladding, the welding heat input can be reduced, the formation of too much brittle hard compound at the interface can be inhibited, and the interface bonding can be ensured. In the cladding process, the spot formed by the near-infrared light laser beam rotates around the spot formed by the blue light laser beam, so that the weld forming can be improved, and defects can be reduced. The method for laser cladding on the aluminum alloy surface can prepare a wear-resistant coating on the aluminum alloy surface, so that the wear resistance of the aluminum alloy surface can be improved.

Description

Technical Field

[0001] This application relates to the field of laser cladding technology, and more specifically, to a laser cladding powder and a method for laser cladding on the surface of aluminum alloy. Background Technology

[0002] Aluminum alloys possess a range of advantages, including high specific strength, low density, and ease of machining, leading to their widespread application in the automotive, shipbuilding, aerospace, and rail transportation industries. However, aluminum alloys exhibit low hardness and relatively poor wear resistance, necessitating surface enhancement to improve their service performance. Currently, surface enhancement of aluminum alloys is primarily achieved through techniques such as electroplating, micro-arc oxidation, and spraying. However, these methods often result in thin coatings, low coating density, and weak bonding strength with the substrate, negatively impacting the performance of the tested specimens.

[0003] Laser cladding, as an advanced surface treatment technology, uses a laser to melt the cladding material and the substrate, achieving a metallurgical bond between them. It can significantly improve the overall performance of materials and extend the service life of components, making it an important direction for the development of material surface modification. Laser cladding has been widely used in the surface modification of steel; however, when laser cladding is applied to non-ferrous metals, such as aluminum alloys, the high reflectivity of the material to the laser beam makes surface modification of aluminum alloys extremely difficult. Some researchers have used a powder-spreading method to pre-spread a layer of powder on the aluminum alloy surface before laser cladding to prepare a reinforced coating. However, this method greatly increases the complexity of the process and cannot be applied to the reinforcement of complex components. Furthermore, aluminum alloys combine with most metals to form brittle and hard intermetallic compounds, and under stress after cladding, the coating may directly separate from the substrate. Summary of the Invention

[0004] This application provides a laser cladding powder and a method for laser cladding on the surface of an aluminum alloy, which can perform wear-resistant surface modification on the aluminum alloy surface.

[0005] The embodiments of this application are implemented as follows:

[0006] In a first aspect, this application provides a laser cladding powder comprising 0.5 wt% to 2 wt% Mo powder, 3 wt% to 6 wt% V powder, 4 wt% to 7 wt% Al powder, 1 wt% to 2 wt% AlB2 powder, 0.5 wt% to 2 wt% CeO2 powder, and the balance Ti powder.

[0007] In the above technical solution, the laser cladding powder of this application can be used to obtain a wear-resistant coating on the surface of aluminum alloy by laser cladding, thereby improving the wear resistance of the aluminum alloy surface.

[0008] The main component of the laser cladding powder is Ti powder. Ti is harder than Al. By adding a certain amount of Mo powder, V powder, and Al powder to the Ti powder, the wear resistance of the wear-resistant coating formed by the laser cladding powder can be improved. Furthermore, by adding a certain amount of AlB2 powder to the Ti powder, AlB2 and Ti can undergo an in-situ chemical reaction, which can simultaneously generate two ceramic phases, Ti3Al and TiB, in the wear-resistant coating. This will greatly improve the wear resistance of the coating. The in-situ formation of ceramic particles can ensure good lattice matching between the ceramic phase and the Ti matrix. At the same time, the addition of rare earth CeO2 can refine the grains, improve the matching degree between the strengthening phase and the Ti matrix, enhance the toughness of the wear-resistant coating, and reduce crack sensitivity.

[0009] In conjunction with the first aspect, in a first possible example of the first aspect of this application, the shape of the laser cladding powder is spherical particles.

[0010] Optionally, the diameter of the spherical particles is 20 μm to 50 μm.

[0011] In a second aspect, this application provides a method for laser cladding on the surface of an aluminum alloy, comprising: using the laser cladding powder of the above embodiment as the cladding material, employing a near-infrared laser beam and a blue laser beam to simultaneously act on the surface of the aluminum alloy substrate for powder feeding laser cladding, wherein the spot formed by the near-infrared laser beam rotates around the spot formed by the blue laser beam.

[0012] In the above technical solution, since both the aluminum alloy matrix and titanium powder are non-ferrous metals, their absorption and utilization rate of near-infrared light is lower than that of visible light. By using a composite beam composed of blue light and near-infrared light for cladding, the welding heat input can be reduced, the formation of too many brittle and hard compounds at the interface can be suppressed, and good interface bonding can be ensured. Furthermore, during the cladding process, the spot formed by the near-infrared laser beam rotates around the spot formed by the blue laser beam, which can improve the weld formation and reduce defects.

[0013] The laser cladding method for aluminum alloy surfaces described in this application can produce a wear-resistant coating on the aluminum alloy surface, thereby improving the wear resistance of the aluminum alloy surface.

[0014] In conjunction with the second aspect, in a first possible example of the second aspect of this application, at any given time, the light spot formed by the near-infrared laser beam and the light spot formed by the blue laser beam partially overlap.

[0015] In conjunction with the second aspect, in a second possible example of the second aspect of this application, the light spot formed by the aforementioned near-infrared laser beam rotates around the center of the light spot formed by the blue laser beam.

[0016] In conjunction with the second aspect, in a third possible example of the second aspect of this application, the light spots formed by the aforementioned near-infrared laser beam and the light spots formed by the blue laser beam are both circular, with the diameter of the light spot formed by the near-infrared laser beam being 1.5 mm to 3 mm and the diameter of the light spot formed by the blue laser beam being 1.5 mm to 3 mm.

[0017] In conjunction with the second aspect, in a fourth possible example of the second aspect of this application, the distance between the center of the spot formed by the aforementioned near-infrared laser beam and the center of the spot formed by the blue laser beam is 0.3 mm to 1 mm.

[0018] In the above example, when the diameter of the spot formed by the near-infrared laser beam is 1.5mm to 3mm, the diameter of the spot formed by the blue laser beam is 1.5mm to 3mm, and the distance between the center of the spot formed by the near-infrared laser beam and the center of the spot formed by the blue laser beam is 0.3mm to 1mm, and the spot formed by the near-infrared laser beam rotates around the center of the spot formed by the blue laser beam, it can be ensured that at any given time, the spot formed by the near-infrared laser beam and the spot formed by the blue laser beam partially overlap, thereby improving weld formation and reducing defects.

[0019] In conjunction with the second aspect, in the fifth possible example of the second aspect of this application, the frequency at which the light spot formed by the aforementioned near-infrared laser beam rotates around the light spot formed by the blue laser beam is 100Hz to 500Hz.

[0020] In conjunction with the second aspect, in the sixth possible example of the second aspect of this application, the power of the aforementioned near-infrared laser beam is 0.5kW to 3kW, and the power of the blue laser beam is 0.5kW to 3kW.

[0021] In conjunction with the second aspect, in the seventh possible example of the second aspect of this application, the laser cladding rate is 5 m / min to 30 m / min. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 The shape of the laser beam formed in this embodiment of the application;

[0024] Figure 2 This is a schematic diagram of the laser cladding process on the surface of an aluminum alloy according to an embodiment of this application;

[0025] Figure 3 This is a partial schematic diagram of the laser cladding process on the surface of an aluminum alloy according to an embodiment of this application;

[0026] Figure 4 The laser beam shapes formed by Comparative Examples 1 and 2 of this application are shown.

[0027] Figure 5 The laser beam shapes formed by Comparative Examples 3 and 4 of this application are shown.

[0028] Figure 6 This is a forming diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Embodiment 1 of this application;

[0029] Figure 7 This is a cross-sectional metallographic image of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Embodiment 1 of this application;

[0030] Figure 8 These are forming diagrams of the wear-resistant coatings formed on the surface of an aluminum alloy substrate in Comparative Examples 1 and 2 of this application.

[0031] Figure 9 This is a forming diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 3 of this application;

[0032] Figure 10 This is a cross-sectional view of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 3 of this application;

[0033] Figure 11 This is a forming diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 4 of this application;

[0034] Figure 12 This is a cross-sectional view of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 4 of this application;

[0035] Figure 13 This is a forming diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 5 of this application;

[0036] Figure 14 This is a cross-sectional metallographic image of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 5 of this application;

[0037] Figure 15 The Ti3Al ceramic reinforcing phase in the wear-resistant coating formed on the surface of the aluminum alloy substrate in Example 1 of this application;

[0038] Figure 16 The TiB ceramic reinforcing phase in the wear-resistant coating formed on the surface of the aluminum alloy substrate in Example 1 of this application;

[0039] Figure 17This is a cross-sectional microhardness distribution diagram in the depth direction of the aluminum alloy substrate after laser cladding in Example 1 of this application;

[0040] Figure 18 This is a cross-sectional microhardness distribution diagram in the depth direction of the aluminum alloy substrate that has undergone laser cladding in Comparative Example 5 of this application.

[0041] Figure 19 This is a friction and wear test diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Embodiment 1 of this application;

[0042] Figure 20 This is a friction and wear test diagram of the aluminum alloy substrate in Embodiment 1 of this application;

[0043] Figure 21 This is a friction and wear test diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 5 of this application.

[0044] Icons: 100-Aluminum alloy substrate; 200-Clad station platform; 300-Laser head; 301-Laser beam; 302-Near-infrared laser beam; 303-Blue laser beam; 400-Laser cladding powder; 500-Wear-resistant coating. Detailed Implementation

[0045] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this application. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0046] The following is a detailed description of a laser cladding powder and a method for laser cladding on an aluminum alloy surface, based on embodiments of this application:

[0047] This application provides a laser cladding powder comprising 0.5wt% to 2wt% Mo powder, 3wt% to 6wt% V powder, 4wt% to 7wt% Al powder, 1wt% to 2wt% AlB2 powder, 0.5wt% to 2wt% CeO2 powder, and the balance Ti powder.

[0048] As an example, the mass percentage of Mo powder in the laser cladding powder can be 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, or 2wt%.

[0049] The mass percentage of V powder in the laser cladding powder can be 3wt%, 3.2wt%, 3.5wt%, 3.8wt%, 4wt%, 4.2wt%, 4.5wt%, 4.8wt%, 5wt%, 5.2wt%, 5.5wt%, 5.8wt%, or 6wt%.

[0050] The mass percentage of Al powder in the laser cladding powder can be 4 wt%, 4.2 wt%, 4.5 wt%, 4.8 wt%, 5 wt%, 5.2 wt%, 5.5 wt%, 5.8 wt%, 6 wt%, 6.2 wt%, 6.5 wt%, 6.8 wt%, or 7 wt%.

[0051] The mass percentage of AlB2 powder in the laser cladding powder can be 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, or 2 wt%.

[0052] The mass percentage of CeO2 powder in the laser cladding powder can be 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, or 2wt%.

[0053] Optionally, the laser cladding powder is in the shape of spherical particles.

[0054] Optionally, the diameter of the spherical particles is 20 μm to 50 μm.

[0055] As an example, the diameter of the spherical particles can be 20μm, 22μm, 25μm, 28μm, 30μm, 32μm, 35μm, 38μm, 40μm, 42μm, 45μm, 48μm or 50μm.

[0056] The main component of the laser cladding powder is Ti powder. Ti is harder than Al. By adding a certain amount of Mo, V, and Al powder to the Ti powder, the wear resistance of the wear-resistant coating formed by the laser cladding powder can be improved. Furthermore, by adding a certain amount of AlB2 powder to the Ti powder, an in-situ chemical reaction occurs between AlB2 and Ti, simultaneously generating both Ti3Al and TiB ceramic phases in the wear-resistant coating. This greatly enhances the wear resistance of the coating, and the in-situ formation of ceramic particles ensures good lattice matching between the ceramic phase and the Ti matrix. Simultaneously, the addition of rare earth CeO2 refines the grain size, improves the matching degree between the reinforcing phase and the Ti matrix, enhances the toughness of the wear-resistant coating, and reduces crack sensitivity. The laser cladding powder of this application can be used to prepare wear-resistant coatings on aluminum alloy surfaces via laser cladding, thereby improving the wear resistance of the aluminum alloy surface.

[0057] This application also provides a method for laser cladding on the surface of an aluminum alloy, which includes the following steps:

[0058] S1. Preparation of cladding raw materials

[0059] Ti powder, Mo powder, V powder, Al powder, AlB2 powder and CeO2 powder are mixed in a certain proportion to obtain a first mixed powder. The first mixed powder is further mixed by ball milling to obtain a second mixed powder. The second mixed powder is then dried for later use.

[0060] Optionally, during the ball milling process, the ball-to-powder ratio is 3:1, the ball mill jar is filled with argon gas, the rotation speed is 300 r / min to 500 r / min, and the milling time is 300 min to 400 min.

[0061] Alternatively, drying can be carried out in a vacuum heating furnace.

[0062] Optionally, the temperature of the vacuum heating furnace is set to 100°C and the heating time is 300 min.

[0063] S2. Prepare the aluminum alloy substrate.

[0064] Remove the oxide film from the surface of the aluminum alloy substrate, and clean the oxide film on the surface of the aluminum alloy substrate with acid and alkali solutions respectively. Then wash off the acid or alkali solution on the surface of the aluminum alloy substrate with water, wipe it with acetone and alcohol, and blow it dry for later use.

[0065] Alternatively, methods for removing the oxide film from the surface of the aluminum alloy substrate include cleaning with a stainless steel wire brush.

[0066] Optionally, when cleaning the oxide film on the surface of the aluminum alloy substrate with acid and alkali solutions respectively, the aluminum alloy substrate is first placed in the alkali solution for cleaning, then the alkali solution on the surface of the aluminum alloy substrate is washed away with water, then the aluminum alloy substrate is placed in the acid solution for cleaning, and finally the acid solution on the surface of the aluminum alloy substrate is washed away with water.

[0067] Optionally, the alkaline solution includes a 5 wt% to 10 wt% sodium hydroxide solution.

[0068] Optionally, the aluminum alloy substrate is cleaned in an alkaline solution for 3 to 5 minutes.

[0069] Optionally, the acid solution includes a 20wt% to 30wt% nitric acid solution.

[0070] Optionally, the aluminum alloy substrate is cleaned in acid for 1 to 3 minutes.

[0071] S3. Set the parameters for laser cladding.

[0072] Adjust the spot of the composite laser beam formed by the near-infrared laser beam and the blue laser beam to the starting position of the cladding. Set the motion trajectory of the spot formed by the near-infrared laser beam and the spot formed by the blue laser beam, the distance between the spot formed by the near-infrared laser beam and the spot formed by the blue laser beam, the rotation frequency of the spot formed by the near-infrared laser beam, the power of the near-infrared laser beam and the blue laser beam, the laser cladding rate, the overlap amount, the powder feeder speed, and the protective gas flow rate.

[0073] Please see Figure 1 The spot formed by the near-infrared laser beam 302 rotates around the spot formed by the blue laser beam 303.

[0074] Both the near-infrared laser beam and the blue laser beam are uniformly distributed heat sources.

[0075] Optionally, the spot formed by the near-infrared laser beam and the spot formed by the blue laser beam partially overlap.

[0076] Optionally, the spot formed by the near-infrared laser beam rotates around the center of the spot formed by the blue laser beam.

[0077] Both the near-infrared laser beam and the blue laser beam form circular spots. The diameter of the spot formed by the near-infrared laser beam is 1.5mm to 3mm, and the diameter of the spot formed by the blue laser beam is 1.5mm to 3mm.

[0078] As an example, the diameter of the spot formed by the near-infrared laser beam can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, or 3mm.

[0079] As an example, the diameter of the spot formed by the blue laser beam can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm or 3mm.

[0080] It should be noted that the diameter of the spot formed by the near-infrared laser beam and the diameter of the spot formed by the blue laser beam can be the same or different. For example, the diameter of the spot formed by the near-infrared laser beam and the diameter of the spot formed by the blue laser beam can both be 1.5mm, 2mm, 2.5mm or 3mm; or the diameter of the spot formed by the near-infrared laser beam is 1.8mm and the diameter of the spot formed by the blue laser beam is 2mm.

[0081] The distance between the center of the spot formed by the near-infrared laser beam and the center of the spot formed by the blue laser beam is 0.3 mm to 1 mm.

[0082] As an example, the distance between the center of the spot formed by the near-infrared laser beam and the center of the spot formed by the blue laser beam can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm.

[0083] When the diameter of the spot formed by the near-infrared laser beam is 1.5mm to 3mm, the diameter of the spot formed by the blue laser beam is 1.5mm to 3mm, and the distance between the center of the spot formed by the near-infrared laser beam and the center of the spot formed by the blue laser beam is 0.3mm to 1mm, and the spot formed by the near-infrared laser beam rotates around the center of the spot formed by the blue laser beam, it can be ensured that at any time, the spots formed by the near-infrared laser beam and the spots formed by the blue laser beam partially overlap, thereby improving weld formation and reducing defects.

[0084] The frequency at which the spot formed by the near-infrared laser beam rotates around the spot formed by the blue laser beam is 100Hz to 500Hz.

[0085] As an example, the frequency at which the spot formed by the near-infrared laser beam rotates around the spot formed by the blue laser beam can be 100Hz, 150Hz, 200Hz, 250Hz, 300Hz, 350Hz, 400Hz, 450Hz, or 500Hz.

[0086] The power of the near-infrared laser beam is 0.5kW to 3kW, and the power of the blue laser beam is 0.5kW to 3kW.

[0087] As an example, the power of the near-infrared laser beam can be 0.5kW, 0.8kW, 1kW, 1.2kW, 1.5kW, 1.8kW, 2kW, 2.2kW, 2.5kW, 2.8kW, or 3kW.

[0088] The power of the blue laser beam can be 0.5kW, 0.8kW, 1kW, 1.2kW, 1.5kW, 1.8kW, 2kW, 2.2kW, 2.5kW, 2.8kW or 3kW.

[0089] It should be noted that the power of the near-infrared laser beam and the power of the blue laser beam can be the same or different. For example, the power of the near-infrared laser beam and the power of the blue laser beam can both be 0.5kW, 1kW, 1.5kW, 2kW, 2.5kW, or 3kW; or the power of the near-infrared laser beam can be 1.2kW and the power of the blue laser beam can be 0.8kW.

[0090] The laser cladding rate is 5 m / min to 30 m / min.

[0091] As an example, the laser cladding rate can be 5 m / min, 10 m / min, 15 m / min, 20 m / min, 25 m / min or 30 m / min.

[0092] The overlap should be 40% to 80% of the lane width.

[0093] As an example, the overlap can be 40%, 50%, 60%, 70%, or 80% of the lane width.

[0094] The powder feeder speed is 1 r / min to 5 r / min.

[0095] As an example, the powder feeder speed can be 1 r / min, 2 r / min, 3 r / min, 4 r / min or 5 r / min.

[0096] The protective gas is an inert gas, including any one or more of helium, argon, and xenon.

[0097] The protective gas flow rate is 10L / min to 35L / min.

[0098] As an example, the protective gas flow rate can be 10L / min, 15L / min, 20L / min, 25L / min, 30L / min or 35L / min.

[0099] S4, Laser Cladding

[0100] Place the laser cladding powder into the powder feeder, and place the treated aluminum alloy substrate onto the cladding station platform. Turn on the protective gas, adjust the laser focus position to be on the surface of the aluminum alloy substrate, and ensure that the focus of the near-infrared laser beam and the focus of the blue laser beam are on the same plane. Run the program to complete the laser cladding of the aluminum alloy substrate.

[0101] Please see Figure 2 and 3 An aluminum alloy substrate 100 is located on a cladding station platform 200. A laser head 300 is located on the upper side of the aluminum alloy substrate 100 and emits a laser beam 301. The laser beam 301 acts on the surface of the aluminum alloy substrate 100, causing the laser cladding powder 400 to form a wear-resistant coating 500 on the surface of the aluminum alloy substrate 100.

[0102] Since both the aluminum alloy substrate and titanium powder are non-ferrous metals, their absorption and utilization rate of near-infrared light is lower than that of visible light. By using a composite beam composed of blue light and near-infrared light for cladding, the welding heat input can be reduced, the formation of excessive brittle and hard compounds at the interface can be suppressed, and good interfacial bonding can be ensured. Furthermore, during the cladding process, the spot formed by the near-infrared laser beam rotates around the spot formed by the blue laser beam, which can improve weld formation and reduce defects. The laser cladding method on the aluminum alloy surface of this application can produce a wear-resistant coating on the aluminum alloy surface, thereby improving the wear resistance of the aluminum alloy surface.

[0103] The following describes in further detail a laser cladding powder and a method for laser cladding on an aluminum alloy surface, with reference to embodiments.

[0104] Example 1

[0105] This application provides a laser cladding powder and a method for laser cladding on an aluminum alloy surface, which includes the following steps:

[0106] The laser cladding powder comprises: 1.5 wt% Mo powder, 3.8 wt% V powder, 5.3 wt% Al powder, 1.5 wt% AlB2 powder, 1.6 wt% CeO2 powder, and the balance Ti powder. The laser cladding powder is in the form of spherical particles with a diameter of 20 μm to 50 μm.

[0107] Laser cladding methods for aluminum alloy surfaces include:

[0108] S1. Preparation of cladding raw materials

[0109] Ti powder, Mo powder, V powder, Al powder, AlB2 powder, and CeO2 powder were mixed in a certain proportion to obtain a first mixed powder. The first mixed powder was further mixed by ball milling to obtain a second mixed powder. During the ball milling process, the ball-to-powder ratio was 3:1, the ball mill jar was filled with argon gas, the rotation speed was 350 r / min, and the ball milling time was 400 min. Then, the second mixed powder was dried in a vacuum heating furnace with the temperature set at 100℃ and the heating time being 300 min.

[0110] S2. Prepare the aluminum alloy substrate.

[0111] Use stainless steel wire to clean the surface of a 10mm thick aluminum alloy substrate to remove the oxide film. Then, place the aluminum alloy substrate in a 5wt% sodium hydroxide solution for 5 minutes and rinse with water to remove the alkaline solution. Next, place the aluminum alloy substrate in a 30wt% nitric acid solution for 3 minutes and rinse with water to remove the acid. Finally, wipe the surface of the aluminum alloy substrate with acetone and alcohol and blow dry.

[0112] S3. Set the parameters for laser cladding.

[0113] Adjust the spot of the composite laser beam formed by the near-infrared laser beam and the blue laser beam to the cladding initiation position, such as... Figure 1 As shown, the spot formed by the near-infrared laser beam 302 rotates around the spot formed by the blue laser beam 303. Both the near-infrared and blue laser beams are uniformly distributed heat sources. Both the near-infrared and blue laser beam spots are circular, with a diameter of 1.8 mm and a diameter of 2 mm. The distance between the centers of the near-infrared and blue laser beam spots is 0.5 mm. The rotation frequency of the near-infrared laser beam spot around the blue laser beam spot is 300 Hz. The power of the near-infrared laser beam is 1.2 kW, and the power of the blue laser beam is 0.8 kW. The laser cladding rate is 5 m / min to 30 m / min, the overlap is 40% to 80% of the pass width, the powder feeder speed is 1 r / min to 5 r / min, and the protective gas is helium with a flow rate of 18 L / min.

[0114] S4, Laser Cladding

[0115] Laser cladding powder is placed in a powder feeder, and the treated aluminum alloy substrate is placed on the cladding station platform. The protective gas is turned on, and the laser focus is adjusted to be on the surface of the aluminum alloy substrate, with the focus of the near-infrared laser beam and the focus of the blue laser beam on the same plane. The program is run to complete the laser cladding of the aluminum alloy substrate, forming a wear-resistant coating on the surface of the aluminum alloy substrate.

[0116] Comparative Example 1

[0117] The comparative example in this application changes the laser beam based on Example 1, such as... Figure 4 As shown, only near-infrared laser beams are used, and the power of the near-infrared laser beam is 1.5kW, while other parameters remain unchanged.

[0118] Comparative Example 2

[0119] The comparative example in this application changes the laser beam based on Example 1, such as... Figure 4 As shown, only near-infrared laser beams are used, and the power of the near-infrared laser beam is 2kW, while other parameters remain unchanged.

[0120] Comparative Example 3

[0121] The comparative example in this application changes the trajectory of the laser beam based on Example 1, such as... Figure 5 As shown, the center of the spot formed by the near-infrared laser beam coincides with the center of the spot formed by the blue laser beam. The spot formed by the near-infrared laser beam is located inside the spot formed by the blue laser beam, and other aspects remain unchanged.

[0122] Comparative Example 4

[0123] The comparative example in this application changes the trajectory of the laser beam based on Example 1, such as... Figure 5 As shown, the center of the spot formed by the near-infrared laser beam coincides with the center of the spot formed by the blue laser beam. The spot formed by the near-infrared laser beam is located inside the spot formed by the blue laser beam. The power of the near-infrared laser beam is 1kW, the power of the blue laser beam is 1kW, and other parameters remain unchanged.

[0124] Comparative Example 5

[0125] The comparative example in this application is based on Example 1, but the laser cladding powder is changed. The laser cladding powder is pure Ti powder, and everything else remains the same.

[0126] Experimental Example 1

[0127] The forming diagram, cross-sectional diagram, or cross-sectional metallographic diagram of the wear-resistant coating formed on the surface of the aluminum alloy substrate in Examples 1, 3-5 are as follows: Figures 6-14 As shown.

[0128] Figure 6 This is a forming diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Embodiment 1 of this application. Figure 7 This is a cross-sectional metallographic image of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Embodiment 1 of this application. Figure 6 and Figure 7 It can be seen that the wear-resistant coating is of high quality, with a smooth surface, no internal defects, and good adhesion between the wear-resistant coating and the aluminum alloy substrate.

[0129] Figure 8 The figures show the forming diagrams of the wear-resistant coatings formed on the surface of the aluminum alloy substrate in Comparative Examples 1 and 2 of this application. It can be seen that after the cladding is completed, both the wear-resistant coatings and the aluminum alloy substrates of Comparative Examples 1 and 2 crack directly.

[0130] Figure 9 This is a forming diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 3 of this application. Figure 10 The cross-sectional view of the wear-resistant coating formed on the surface of the aluminum alloy substrate in Comparative Example 3 of this application shows that after the cladding is completed, although the wear-resistant coating and the aluminum alloy substrate do not crack, the surface of the aluminum alloy substrate is uneven with large undulations, and there are gaps at the interface that are not bonded.

[0131] Figure 11 This is a forming diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 4 of this application. Figure 12 The image shows a cross-sectional view of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 4 of this application. It can be seen that the wear-resistant coating has not been well improved. Its surface is uneven with large undulations, and there are gaps at the interface where there is no bonding.

[0132] Figure 13 This is a forming diagram of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 5 of this application. Figure 14 The image shows a cross-sectional metallographic image of the wear-resistant coating formed on the surface of an aluminum alloy substrate in Comparative Example 5 of this application. It can be seen that the wear-resistant coating is of high quality, with a smooth surface, no internal defects, and good adhesion between the wear-resistant coating and the aluminum alloy substrate.

[0133] Experimental Example 2

[0134] Example 1: The wear-resistant coating formed on the surface of an aluminum alloy substrate using Ti3Al and TiB ceramic reinforcing phases as shown in Example 1. Figures 15-16 As shown. Figure 15 To analyze the microstructure of the coating using scanning electron microscopy, Figure 16 To analyze the microstructure of the coating using transmission electron microscopy.

[0135] like Figures 15-16 As shown, further microstructure analysis revealed that two ceramic phases were indeed formed inside the wear-resistant coating, including a large, elongated Ti3Al and a smaller, hexagonal TiB. The ceramic phases and the wear-resistant coating were well bonded, and the formation of the in-situ ceramic phases ensured that the wear-resistant coating had high wear resistance.

[0136] Experimental Example 3

[0137] The Vickers hardness in the depth direction of the aluminum alloy substrates after laser cladding in Example 1 and Comparative Example 1 was tested respectively. Figures 17-18As shown; then the friction and wear of the wear-resistant coating formed on the surface of the aluminum alloy substrate in Example 1, the friction and wear of the aluminum alloy substrate in Example 1, and the friction and wear of the wear-resistant coating formed on the surface of the aluminum alloy substrate in Comparative Example 5 were tested respectively. Figures 19-21 As shown. Figures 17-18 The hardness of the coating was tested using a Vickers hardness tester. Figures 19-21 The wear resistance of the coating was tested using a friction and wear testing machine.

[0138] Depend on Figures 17-18 It can be seen that the average hardness value of the wear-resistant coating formed in Example 1 is close to 700 HV, the average hardness value of the wear-resistant coating formed in Comparative Example 1 is close to 310 HV, while the hardness of the aluminum alloy substrate is only 60 HV. That is, the hardness value of the wear-resistant coating formed in Example 1 can reach more than 10 times the hardness value of the aluminum alloy substrate, while the hardness value of the wear-resistant coating formed in Comparative Example 1 is only 5.4 times the hardness value of the aluminum alloy substrate.

[0139] Depend on Figures 19-21 It can be seen that the wear resistance of the wear-resistant coating formed in Example 1 is 9.3 times that of the aluminum alloy substrate, while the wear resistance of the wear-resistant coating formed in Comparative Example 1 is 5.8 times that of the aluminum alloy substrate.

[0140] The above description is merely a specific embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method of laser cladding on an aluminum alloy surface, characterized by, The method for laser cladding on the surface of an aluminum alloy comprises: using a laser cladding powder as a cladding raw material, using a near-infrared laser beam and a blue laser beam to act on a surface of an aluminum alloy substrate for powder feeding laser cladding, and the spot formed by the near-infrared laser beam rotates around the spot formed by the blue laser beam. The laser cladding powder comprises 0.5wt%-2wt% Mo powder, 3wt%-6wt% V powder, 4wt%-7wt% Al powder, 1wt%-2wt% AlB2 powder, 0.5wt%-2wt% CeO2 powder, and a balance of Ti powder.

2. The method of laser cladding on an aluminum alloy surface according to claim 1, characterized in that, The laser cladding powder is in the shape of spherical particles.

3. The method of laser cladding on an aluminum alloy surface according to claim 2, wherein The diameter of the spherical particles is 20μm-50μm.

4. The method of laser cladding on an aluminum alloy surface of claim 1, wherein, At any time, the spot formed by the near-infrared laser beam and the spot formed by the blue laser beam partially overlap.

5. The method of laser cladding on an aluminum alloy surface of claim 1, wherein, The spot formed by the near-infrared laser beam rotates around the center of the spot formed by the blue laser beam.

6. The method of laser cladding on an aluminum alloy surface according to claim 4, wherein The spot formed by the near-infrared laser beam and the spot formed by the blue laser beam are both circular, the diameter of the spot formed by the near-infrared laser beam is 1.5mm-3mm, and the diameter of the spot formed by the blue laser beam is 1.5mm-3mm.

7. The method of laser cladding on an aluminum alloy surface according to claim 6, characterized in that, The distance between the center of the spot formed by the near-infrared laser beam and the center of the spot formed by the blue laser beam is 0.3mm-1mm.

8. The method of laser cladding on an aluminum alloy surface of claim 1, wherein, The frequency of rotation of the spot formed by the near-infrared laser beam around the spot formed by the blue laser beam is 100Hz-500Hz.

9. The method of laser cladding on an aluminum alloy surface of claim 1, wherein, The power of the near-infrared laser beam is 0.5kW-3kW, and the power of the blue laser beam is 0.5kW-3kW.

10. The method of laser cladding on an aluminum alloy surface of claim 1, wherein, The laser cladding rate is 5m / min-30m / min.

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