Method and device for repairing damage to a mounting surface of an axle housing body

Abstract

The present application discloses a method and a device for repairing damage to a mounting surface of an axle housing body. The method comprises the following steps: acquiring a measurement of the size of a corrosion pit at a damaged location on a mounting surface of an axle housing body to determine defective areas of the damaged location, and removing corrosion layers from the defective areas using a subtractive machining treatment; performing a classification of the defective areas and spraying them accordingly based on the types of defects to obtain appropriate repair areas; and performing subtractive post-processing on each repair area to restore the size of the mounting surface.According to the process, corrosion products can be removed from the mounting surface of the axle housing body, the size of the axle housing body can be efficiently and accurately restored by carrying out additive and subtractive treatments sequentially based on the removal of corrosion products by machining, the influence of a conventional thermal repair agent on the structural condition, dimensional accuracy and mechanical properties of parts is eliminated, and the service life of the axle bearing body is further extended.

Description

CROSS-REFERENCES TO RELATED REGISTRATIONS

[0001] The present application claims priority over Chinese patent application No. 202211529888.9, filed on November 30, 2022, entitled “Method for Improving Bonding Strength of High-Pressure Cold Sprayed Coating of Aluminum Alloy Component”, and Chinese patent application No. 202211248277.7, filed on October 12, 2022, entitled “Method and Device for Repairing Damage of Mounting Surface of Axle Box Body”, all of which are incorporated herein by reference. AREA

[0002] The present application relates to the field of rail transport, and in particular to a method and a device for repairing damage to the mounting surface of an axle box body, and a method for improving the adhesion strength of a cold-sprayed high-pressure coating made of an aluminum alloy component. BACKGROUND

[0003] Aluminum alloy materials are widely used in transportation, vehicle manufacturing, aerospace, and other sectors due to their high specific strength, high specific modulus, and good corrosion resistance. Aluminum alloys are important materials for the lightweight construction of high-speed trains, automobiles, and aircraft. The axle housing is a critical component of rail vehicles, such as high-speed trains and light rail systems, and is generally made of a high-strength aluminum alloy. Zinc phosphate paint is typically sprayed on for protection, preventing galvanic corrosion at the interfaces between the axle housing and other components.During vehicle operation, the zinc phosphate coating is easily damaged due to friction and environmental influences, leading to soil exposure and causing galvanic corrosion on the mounting surface of the axle bearing body. Various corrosion pits form on its surface, causing material loss on the mounting surface of the aluminum alloy axle bearing body. This results in excessive surface roughness that fails to meet the requirements for its intended use, leading to a high component rejection rate.

[0004] The primary measure currently taken to address such problems is to remove the corrosion layer caused by galvanic corrosion on the mounting surface of the axle bearing body through machining, in order to resolve the issue of inaccurate surface roughness. However, after one or two machining cycles, the size of the axle bearing body's mounting surface reaches its minimum limit. If it rusts again, it cannot be repaired by machining and can only be scrapped or sealed for storage. Such an approach results in high maintenance costs and significant resource waste.However, commonly used material repair and post-processing technologies based on high-energy beams such as lasers, plasma, and arcs present several problems that are currently difficult to overcome when repairing high-strength 7-series aluminum alloys. These problems include easy workpiece cracking, a large heat-affected area, and low hardness of the repair layer. Limited by the processing characteristics of high-strength aluminum alloys, the use of arc surface finishing or high-energy laser coating technologies for repair inevitably damages the substrate structure of the aluminum alloy. This leads to a reduction in the mechanical properties of the repaired area and a decrease in accuracy caused by the deformation of precision components due to heat input.

[0005] Currently, cold spray technology is used to rework and repair the corroded surface of the axle bearing body. However, the coating's adhesion strength generally only reaches 40 MPa to 60 MPa due to the low adhesion of a typical cold-sprayed high-pressure coating, which cannot meet the usage requirements of a high-speed train for high-standard components (where the adhesion strength of the repaired coating must exceed 100 MPa).

[0006] In summary, it is urgently necessary to develop new repair technologies and their corresponding repair processes. BRIEF SUMMARY

[0007] The present application provides a method and a device for repairing damage to the mounting surface of an axle bearing body, which are used to remove the corroded surface of the mounting surface of the axle bearing body, and based on this, not only can the corrosion products be efficiently removed, but the size of the axle bearing body can also be restored, which eliminates the influence of a conventional thermal repair agent on the structural condition, dimensional accuracy and mechanical properties of parts and further extends the service life of the axle bearing body.

[0008] The present application provides a method for repairing damage to a mounting surface of an axle bearing body, comprising the following steps: Obtaining a size measurement result of a corrosion depression at a damaged position on a mounting surface of an axle bearing body in order to determine defective areas of the damaged position, and removing corrosion layers of the defective areas by using a subtractive machining treatment; Performing a classification of the defective areas and spraying the defective areas accordingly, based on one type of each defective area, to obtain appropriate repair areas; and Perform subtractive rework on each of the repair areas to restore the size of the mounting surface.

[0009] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the step of obtaining the size measurement result of the corrosion depression at the damaged position on the mounting surface of the axle bearing body in order to determine defective areas of the damaged position, and of removing corrosion layers of the defective areas by using a subtractive machining treatment, comprises the following steps: Determining each of the defective areas of the damaged position based on a position of the corrosion pit, wherein each of the defective areas has at least one corrosion pit; Obtaining a maximum depth of corrosion pitting in the same defective area and a corresponding area of ​​defective area to determine an area for machining treatment; and Removal of corrosion layers from each of the defective areas by using a subtractive machining treatment within each area for a mechanical machining treatment.

[0010] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the step of obtaining the maximum depth of the corrosion pit in the same defective area and the area of ​​the corresponding defective area in order to determine the area for a machining treatment comprises the following steps: Selecting multiple corrosion pits in the same defective area, measuring the depth of each selected corrosion pit using a depth calibrator, and obtaining the maximum depth of the corrosion pit by comparison; Measuring and calculating the area of ​​the defective region; and Determining the area for mechanical machining treatment based on the maximum depth of the corrosion pit and the area of ​​the defective region; wherein the area of ​​the region to be machined is larger than the area of ​​the defective region and the depth of the region to be machined is not less than the maximum depth of the corrosion pit.

[0011] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the method, after the step of removing corrosion layers from each of the defective areas by using a subtractive machining treatment within each area for a mechanical machining treatment, further comprises the following steps: Performing a rounding transition process on the defective areas that have undergone subtractive machining; where the angle between a rounding of the defective area that has undergone the rounding transition process and a base surface is not greater than 30°.

[0012] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the step of performing a classification on the defective areas and spraying the defective areas accordingly, based on the type of each of the defective areas, in order to obtain corresponding repair areas, comprises the following steps: Obtaining a length and width of each corrosion depression in the defective areas; Performing a classification of the defective areas based on the length and width of each corrosion pit to determine types of defective areas; wherein the types of defective areas include point defects, line defects, and area defects; For the point defect, drive a spray gun to spray perpendicularly to the center of the defective area; For the linear defect, driving a spray gun to move along a longitudinal direction of the defective area, with a movement path of the spray gun remaining unchanged in a lateral direction, and determining back-and-forth movement times of the spray gun based on the maximum depth of the corrosion pit; and For the surface defect, drive a spray gun to move along a longitudinal and a transverse direction of the defective area, and determine back-and-forth movement times of the spray gun based on the maximum depth of the corrosion depression.

[0013] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the point defect is a corrosion depression with a length and width of both less than 5 mm; the linear defect is a corrosion depression with a length of more than or equal to 5 mm and a width of less than or equal to 5 mm; and defects other than the point defect and the linear defect are planar defects.

[0014] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the method further comprises the following steps prior to the step of obtaining the size measurement result of the corrosion depression at the damaged position on the mounting surface of the axle bearing body in order to determine defective areas of the damaged position and removing corrosion layers of the defective areas by using a subtractive machining treatment: Performing laser cleaning at the damaged location on the mounting surface; and Perform a surface cleaning at the cleaned damaged area to expose the corrosion depression at the damaged area.

[0015] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the step of performing laser cleaning at the damaged position on the mounting surface and performing surface cleaning at the cleaned damaged position to expose the corrosion depression at the damaged position comprises the following steps: Performing laser cleaning at the damaged location on the mounting surface using a laser cleaning system with a laser power of 50 W to 120 W for a cleaning time of 2 min to 5 min; and Perform surface cleaning at the cleaned damaged location using a high-pressure air gun to expose the corrosion depression at the damaged location.

[0016] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the method further comprises the following steps prior to the step of performing a classification on the defective areas and spraying the defective areas accordingly, based on the type of each of the defective areas, in order to obtain corresponding repair areas: Plugging all perforated parts using a plug within the defective areas that have undergone subtractive machining treatment; Sandblasting of the defective areas that had undergone subtractive machining; and Preheating and spraying the defective areas that were to be sandblasted.

[0017] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the surface roughness (Ra) of the defective areas that were subjected to sandblasting is 5.0 µm to 7.6 µm.

[0018] According to the method for repairing damage to a mounting surface of an axle bearing body provided by the present application, the process parameters of preheating and spraying are as follows: Using aluminium alloy powder for preheating and spraying with a powder particle size of 10 µm to 60 µm, a drying temperature of 70 ± 5 °C for the powder, and a preheating and spraying time of 40 min to 60 min; wherein a spray gas used for preheating and spraying is 99.99% nitrogen; where the gas pressure of the spray gas is 3.5 MPa to 5.5 MPa; where the spray distance for preheating and spraying is 5 mm to 20 mm; where the angle between a spray gun and a spray surface for preheating and spraying is not less than 60°.

[0019] The present application further provides a device for repairing damage to a mounting surface of an axle bearing body, which is capable of performing the method for repairing damage to a mounting surface of an axle bearing body as described above.

[0020] The device for repairing damage to a mounting surface of an axle bearing body includes: a size measurement system for obtaining a size measurement result of a corrosion depression at a damaged position on a mounting surface of an axle bearing body; a subtractive machining treatment system for determining defective areas of the damaged position based on the size measurement result of the corrosion depression and for removing corrosion layers of the defective areas by using a subtractive machining treatment; a spray system for performing a classification of the defective areas and corresponding spraying of the defective areas, each based on a type of defective area, in order to obtain corresponding repair areas; and a subtractive rework system for performing subtractive rework on each of the repair areas to restore a certain size of the mounting surface.

[0021] The present application also provides an aluminum alloy powder for use in the aforementioned method for repairing damage to a mounting surface of an axle bearing body. The aluminum alloy powder comprises the following components in weight percent: 3.2% to 7.8% Zn, 2.0% to 2.7% Mg, 1.5% to 2.9% Cu, 0.02% to 0.06% Ti, 0.3% to 1.5% C, 0.05% to 0.20% Zr, 1.0% to 2.8% Nd, 0.01% to 0.08% Sr, with the remainder being Al.

[0022] According to one embodiment of the present application, the aluminium alloy powder has the following components in weight percent: 1.2% to 2.5% Nd and / or 0.02% to 0.06% Sr. It has been shown that Nd and Sr elements within this content range can improve the adhesion strength of the coatings and reduce porosity.

[0023] In some specific examples, Nd is present in an amount of 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4% or 2.5%.

[0024] In some specific examples, Sr is present in an amount of 0.02%, 0.03%, 0.04%, 0.05% or 0.06%.

[0025] According to one embodiment of the present application, the aluminium alloy powder comprises the following components in weight percent: 2.2% to 2.3% Mg, 5.3% to 6.5% Zn, 1.2% to 2.5% Nd, 0.9% to 1.0% C, 0.12% to 0.15% Zr, 2.0% to 2.2% Cu, 0.03% to 0.04% Ti, 0.02% to 0.06% Sr, wherein the remainder is Al.

[0026] According to one embodiment of the present application, the aluminium alloy powder comprises the following components in weight percent: 5.3% Zn, 2.3% Mg, 2.2% Cu, 0.04% Ti, 0.9% C, 0.12% Zr, 1.9% Nd, 0.04% Sr, and wherein the remainder is Al.

[0027] According to one embodiment of the present application, the particle size of the aluminum alloy powder is 10 µm to 60 µm. Generally, a sieve could be used for powder classification. Powders within this particle size range have been shown to be more uniform and exhibit better fluidity.

[0028] According to one embodiment of the present application, the aluminium alloy powder is produced by the process of powder atomization, for example argon atomization.

[0029] The present application also provides a method for producing the aforementioned aluminium alloy powder, comprising: 1) Mixing components according to element proportions; 2) Heating and melting raw materials and carrying out atomization to produce powders; and 3) Drying and sieving the resulting powder to obtain an aluminum alloy powder.

[0030] The present application further includes the use of the aforementioned aluminum alloy powder in repairs using aluminum alloy materials, particularly aluminum alloy materials used in the fields of high-speed railways, automobiles, aircraft, etc. In some specific examples, it is applied to the repair of axle bearing bodies of railway vehicles, such as high-speed trains or light rail vehicles. The axle bearing body is made of a high-strength aluminum alloy, for example, a high-strength aluminum alloy such as 7050FD.

[0031] For practical applications where the adhesion strength of high-pressure cold spraying on high-strength aluminum alloys is low, a method for improving this adhesion is provided. This method allows high-pressure cold spraying technology to be applied to load-bearing key components made of aluminum alloys. It not only restores the surface finish of the high-strength aluminum alloy but also repairs the strength and function of key components. It plays a significant role in promoting the use of high-pressure cold spraying technology in more industrial fields.

[0032] The present application also provides a method for improving the adhesion strength of a cold-sprayed high-pressure coating made of aluminium alloy, which includes: 1) Sandblasting an area to be repaired; 2) Using the aluminum alloy powder as described above for high-pressure cold spraying; and 3) Performing a solution treatment on a workpiece that has been repaired by spraying.

[0033] The aluminum alloy powder of the present application is generally dried before use, for example by placing it in a vacuum drying oven. In some embodiments, the drying temperature of the vacuum drying oven is 60 °C to 70 °C and the drying time is 40 to 60 minutes. After drying, it can be poured into the cold spray powder feed system for spraying.

[0034] According to the embodiment of the present application, the surface of the workpiece to be sprayed is roughened by sandblasting to improve the surface roughness. The spraying process parameters are adjusted according to the depth and area of ​​the repair area. In some embodiments, the surface roughness (Ra) of the workpiece after sandblasting reaches 5.0 µm to 7.6 µm, such as 5.8 µm to 7.6 µm.

[0035] According to an embodiment of the present application, cold spraying is carried out at high pressure at a temperature of 350 °C to 500 °C, for example 400 °C to 500 °C, under a gas pressure of 4.5 MPa to 5.5 MPa, for example 5 MPa to 5.5 MPa.

[0036] According to one embodiment of the present application, the speed of cold spraying with high pressure (spray gun) is 250 mm / s to 350 mm / s, for example 300 mm / s.

[0037] According to one embodiment of the present application, the angle of cold spraying with high pressure (spray gun) is 70° to 90°.

[0038] According to one embodiment of the present application, the solution treatment is carried out at a temperature of 400 °C to 500 °C, for example 455 °C to 460 °C, for a solution treatment time of 30 min to 60 min, for example 35 min to 40 min.

[0039] According to one embodiment of the present application, cold spraying is carried out under high pressure at a temperature of 350 °C to 500 °C and a gas pressure of 4.5 MPa to 5.5 MPa. The spraying speed is 250 mm / s to 350 mm / s, and the spray angle is 70° to 90°. The solution treatment is carried out at a temperature of 400 °C to 500 °C for a solution time of 30 to 60 minutes. It has been shown that powder particles can undergo significant plastic deformation when they collide with the substrate under such preferred conditions, while also creating a corresponding depression on the substrate surface. In combination with the influence of the substrate's surface roughness, excellent bond quality between the powder particles and the substrate can be achieved. It also reduces or eliminates the presence of a hole within the coating.

[0040] The present application describes a heat treatment of the cold-sprayed axle bearing body after cold spraying with high pressure, and the cold-sprayed coating achieves extremely high adhesion strength and extremely low porosity, thereby solving the problem of low adhesion strength and high porosity of ordinary cold-sprayed high-pressure coatings, thus ensuring the performance of the repaired components.

[0041] The method provided in this application for repairing damage to the mounting surface of axle bearing bodies innovatively introduces additive cold spraying technology with the function of deposited metal materials in a low-temperature solid state within additive (subtractive) repair technology. Precise process path design through size measurement and defect classification is provided to repair damaged parts on the mounting surface of the aluminum alloy axle bearing body. Different repair processes are developed for different damage morphologies to address the problems of high maintenance costs and significant resource waste in existing aluminum alloy axle bearing bodies.

[0042] In the method described in the present application, the size of the corrosion pit at the damaged location on the mounting surface of the axle bearing body is measured to determine defective areas that can be subjected to subtractive machining. This improves the operational accuracy of removing corrosion layers. A fine classification of the defective areas is performed, and the corresponding defective areas are sprayed according to the type of defective area as described in this method, thus providing precise spraying. Subtractive post-processing is then carried out on each repaired area to restore the size of the mounting surface.Compared to the state of the art, this method repairs corroded defective areas using additive manufacturing via high-pressure cold spraying based on subtractive machining, instead of simply machining the mounting surface of an axle bearing body. According to this method, corrosion products can be removed from the mounting surface of the axle bearing body, and the size of the axle bearing body can be efficiently and accurately restored by performing additive and subtractive treatments sequentially, based on the removal of the corrosion products by machining. This eliminates the influence of a conventional thermal repair agent on the structural condition, dimensional accuracy, and mechanical properties of parts, further extending the service life of the axle bearing body.

[0043] Furthermore, the method described in the present application could apply a high-pressure cold spraying technology to load-bearing key components made of aluminum alloy. It not only restores the surface condition of an aluminum alloy to a high strength but also repairs the strength and function of key components. It plays an important role in promoting the use of high-pressure cold spraying technology in more industrial fields.

[0044] The present application further provides a device for repairing damage to a mounting surface of an axle bearing body. By incorporating a dimensional measuring system, a subtractive machining treatment system, a spraying system, and a subtractive restoration system, the device for repairing damage to a mounting surface of an axle bearing body is capable of performing the method for repairing damage to a mounting surface of an axle bearing body as described above, thereby possessing all the advantages of the method for repairing damage to a mounting surface of an axle bearing body as described above. The details are not elaborated here.

[0045] The aluminum alloy powder provided in the present application mainly comprises elements such as Al, Zn, Mg, Cu, Ti, C, Zr, Nd, and Sr. The present application improves the strength and hardness of powder particles by adding rare earth elements and refining and strengthening the powder, as well as by inducing in situ precipitation of hard TiC particles within the powder particles through the addition of Ti and C as alloying elements. During the cold spraying process, particles with a higher hardness than the base can be effectively embedded onto the base surface during a high-velocity impact, enabling conventional aluminum alloy powder to form one with higher interfacial adhesion strength.

[0046] Compared to existing cold spraying repair technology, the present application introduces rare earth elements such as Nd and Sr for refining and strengthening by optimizing the powder formula based on the additive manufacturing technology of high-pressure cold spraying. The present application improves the strength and hardness of powder particles by in situ precipitation of hard TiC particles within the powder particles through the addition of Ti and C as alloying elements, thereby achieving better agreement with the base strength.During the spraying process, a lower spray temperature is set to prevent excessive softening of the metal particles after heating, and a higher gas pressure is set to impart greater kinetic energy to the particles during deposition, while simultaneously generating sufficient flattening deformation and improving the compressive stress between particles within the coating. This is more conducive to the formation of a larger area of ​​nail-like impact at the interface when particles collide with the base, causing the oxide film on the surface of the powder and the base to rupture. This creates metallurgical bond points under the kinetic energy of the particle impact, thus greatly improving bond performance.Performing a solution heat treatment on the axle bearing body undergoing spraying and repair can shrink internal gaps, improve the diffusion of interface elements, harden the joining surface, and further improve adhesion strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] To more clearly illustrate the solutions in the present application or the prior art, a brief description of the accompanying drawings, which are necessary for use in describing the embodiments or the prior art, is given below. The accompanying drawings described below are some embodiments of the present application. Other drawings can also be obtained by a person skilled in the art without creative effort based on these accompanying drawings. Fig. Figure 1 is a schematic flowchart of a method for repairing damage to a mounting surface of an axle bearing body, which is provided in the present application. Fig. Figure 2 is a morphology diagram of an aluminium alloy powder produced in embodiment I of the present application. Fig. 3 is a repaired coating by cold spraying, which is produced in embodiment II of the present application. Fig. 4 is a repaired coating by cold spraying, which is produced in comparative embodiment I of the present application. DETAILED DESCRIPTION

[0048] To clarify the objectives, solutions, and advantages of the present application, the solutions in the present application are described below in detail and in full, in conjunction with the accompanying drawings. It should be noted that the described embodiments are part of the embodiments of the present application, not all of them. Based on the embodiments in the present application, all other embodiments that a person skilled in the art could obtain without creative effort are intended to fall within the scope of the present application.

[0049] The present application is further described below in connection with embodiments and comparative embodiments. The embodiment used herein relates to the fact that the present application contains at least one implementation method, but the present application can also be implemented in other ways that differ from this embodiment. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0050] The method for repairing damage to the mounting surface of the axle bearing body (referred to in the present application as "the method") and the device for repairing damage to the mounting surface of the axle bearing body (referred to in the present application as "the device") are below in connection with Fig. 1 described.

[0051] As in Fig. As shown in Figure 1, the method described in the present application for repairing damage to the mounting surface of an axle bearing body comprises the following steps: S1, Obtaining a size measurement result of a corrosion depression at a damaged position on a mounting surface of an axle bearing body in order to determine defective areas of the damaged position, and removing corrosion layers of the defective areas by using a subtractive machining treatment; S2, Performing a classification of the defective areas and spraying the defective areas accordingly based on the types of defective areas in order to obtain appropriate repair areas; and S3, Perform subtractive rework on each of the repair areas to restore the size of the mounting surface.

[0052] In the method described in the present application, step S1 involves measuring the size of the corrosion pit at the damaged location on the mounting surface of the axle bearing body to determine the defective areas that can be subjected to subtractive machining, thus improving the operational accuracy of removing corrosion layers. In step 2, a fine classification of the defective areas is performed, and corresponding defective areas are sprayed based on the type of defect to achieve precise spraying. Based on this, in step 3 of the method, subtractive reworking is carried out on each of the repaired areas to restore the size of the mounting surface.Compared to the state of the art, instead of simply machining the mounting surface of the axle bearing body to remove the corroded surface, this process repairs the corroded defective areas using additive manufacturing via high-pressure cold spraying based on subtractive machining. According to this method, corrosion products can be removed from the mounting surface of the axle bearing body, and the size of the axle bearing body can be efficiently and accurately restored by performing additive and subtractive treatments sequentially, based on the removal of the corrosion products by machining. This eliminates the influence of a conventional thermal repair agent on the structural condition, dimensional accuracy, and mechanical properties of replacement parts, further extending the service life of the axle bearing body.

[0053] To ensure that corrosion depressions at the damaged location are fully exposed, so that subsequent size measurement results are more accurate, and to avoid significant differences that could lead to errors in the subsequent determination and classification of defective areas, it is preferred that a surface pretreatment step be included before step S1.

[0054] Preferably, the surface pretreatment step may include the following steps: S01, Performing laser cleaning at the damaged location on the mounting surface; and S02, Performing surface cleaning at the cleaned damaged location to expose the corrosion depression at the damaged location.

[0055] To remove rust and contaminants from the mounting surface of the axle bearing body and to improve the accuracy of the subsequent size measurement results and the measurement efficiency, it is preferred that steps S01 and S02, as described above, further include: S011, Performing laser cleaning at the damaged position on the mounting surface using a laser cleaning system with a laser power of 50 W to 120 W for a cleaning time of 2 min to 5 min; and S021, Performing surface cleaning at the cleaned damaged location using a high-pressure air gun to expose the corrosion depression at the damaged location.

[0056] In step S011, the cleaning time is preferably 3 minutes to ensure that all corrosion pits at the damaged location are fully exposed.

[0057] In step S021, a high-pressure air gun is used to perform a second cleaning on the laser-cleaned surface after the laser cleaning to ensure that no contaminants remain at the damaged location.

[0058] In some embodiments, the above step S1 further includes the following steps: S11, Determining each of the defective areas of the damaged position based on the position of the corrosion pit, wherein each of the defective areas has at least one corrosion pit; S12, Obtaining a maximum depth of corrosion pitting in the same defective area and a corresponding defective area to determine an area for machining treatment; and S13, Removal of corrosion layers from each of the defective areas by using a subtractive machining treatment within each area for a mechanical machining treatment.

[0059] In step S11, multiple defective areas at the damaged location can be precisely subdivided based on the distribution of corrosion pits. This allows for specific process paths and parameter settings for each defective area, enabling more accurate and targeted subdivision and classification. Then, in step S12, the maximum depth of the corrosion pit and the area of ​​the corresponding defective region are measured and calculated. This helps determine the depth and area of ​​the subtractive machining treatment in the subsequent step S13, defining a precise and unambiguous area for machining. This prevents the subtractive machining from being too deep or too extensive, thus protecting the mounting surface of the axle bearing body.

[0060] In some embodiments, the above step S12 further includes the following steps: S121, Selecting multiple corrosion pits in the same defective area, and measuring the depth of each selected corrosion pit using a depth calibrator, and obtaining the maximum depth of the corrosion pit by comparison; S122, Measuring and calculating the area of ​​the defective region; and S123, Determining the area for a mechanical machining treatment based on the maximum depth of the corrosion pit and the area of ​​the defective area.

[0061] Preferably, the area of ​​the region for mechanical treatment is larger than the area of ​​the defective area, and the depth of the region for mechanical treatment is not less than the maximum depth of the corrosion pit. This ensures that the subtractive treatment area covers the entire defective area and avoids gaps during the corrosion layer removal process. This can both reduce the area of ​​subtractive treatment and improve the accuracy of corrosion layer removal as much as possible.

[0062] Preferably, to better protect the defective area that has undergone subtractive machining, the following steps are also included, preferably after step S13 mentioned above: S14, Performing a rounding transition process on the defective area that has undergone subtractive machining.

[0063] The angle between the fillet of the defective area, which has undergone the fillet transition process, and the base surface is no greater than 30°. In other words, the process uses a corrosion pit depth calibrator to measure the depth of the corrosion pit, determining the maximum corrosion pit depth among several corrosion pits. The depth of the corrosion pit with the maximum corrosion depth is used as the maximum corrosion pit depth, and 0.2 mm is added to this baseline to perform subtractive machining on the surface of the corrosion pit. The fillet transition process is applied to the edge portion of the area for machining treatment, thus avoiding sharp or right angles. The angle between the fillet and the base surface is no greater than 30°.

[0064] In one embodiment, the steps for measuring the depth of corrosion pits using a corrosion pit depth calibrator are as follows: Place the mounting surface of the axle bearing body flat facing upwards on a platform; Positioning the corrosion pit depth calibrator near the mounting surface of the axle bearing body, gently lowering the corrosion pit depth calibrator to bring a probe into contact with a flat surface, setting a micrometer to zero, then moving the probe close to an edge of the mounting surface of the axle bearing body, and setting a height of the probe to below a depth to be measured on the mounting surface of the axle bearing body; Lifting and moving the probe to the top of an area to be measured, then lowering the probe to continue the measurement; Measuring different parts of the corrosion area at random, with no fewer than 5 measuring points, and recording the maximum depth.

[0065] Based on the measured maximum depth of the corrosion pits and the area, a value of 0.2 mm is added to determine the required machining treatment. Subtractive machining is performed on the repaired portion of the axle bearing body to remove the corrosion layer, and a visual inspection to ensure the machining depth is sufficient is carried out upon completion.

[0066] In some embodiments, the following steps are preferably included between step S1 and step S2 to better protect the mounting surface of the axle bearing body during the repair process: S15, Plugging all perforated parts within the defective areas that have undergone subtractive machining treatment, using plugs; S16, Sandblasting of the defective areas that have undergone subtractive machining treatment; S17, Preheating and spraying the defective areas that were subjected to sandblasting.

[0067] In preferred step S15, the axle bearing body to be repaired is preferably mounted on a specialized fixture to facilitate handling. It is preferred that the use of specialized plugs prior to sandblasting can provide reliable protection for perforated parts, especially threaded parts, within the defective zone. Preferably, the specialized plug used is non-metallic and does not obstruct the path of the particles being sprayed.

[0068] In preferred step S16, the sandblasted surface achieves a uniformly rough condition without metallic luster by sandblasting the defective area that underwent subtractive machining. Preferably, the surface roughness (Ra) of the defective areas subjected to sandblasting is 5.0 µm to 7.6 µm. Preferably, brown corundum sand with a 25 mesh size is used for sandblasting, with a sandblasting pressure of 0.3 MPa to 0.6 MPa, a sandblasting distance of 80 mm to 120 mm, a sandblasting angle of 40° to 70°, and a sandblasting time of 2 min to 5 min.

[0069] In the preferred step S17, preheating and spraying can preheat the mounting surface to be repaired, thereby drying the powder. Preferably, the process parameters for preheating and spraying may include: the use of aluminum alloy powder (such as 7050 aluminum alloy powder) for preheating and spraying with a powder particle size of 10 µm to 60 µm, a drying temperature of 70 ± 5 °C for the powder, and a preheating and spraying time of 40 min to 60 min, wherein the spray gas used for preheating and spraying is 99.99% nitrogen, the gas pressure of the spray gas is 3.5 MPa to 5.5 MPa, the spraying distance for preheating and spraying is 5 mm to 20 mm, and the angle between the spray gun and the spray surface for preheating and spraying is not less than 60°.

[0070] In some embodiments, step S2 further includes the following steps: S21, Maintain a length and width of each corrosion depression in the defective areas; S22, Performing a classification on the defective areas based on the length and width of each corrosion pit to determine the types of defective areas, wherein the types of defective areas include a point defect, a line defect and a planar defect.

[0071] The size of each corrosion pit is accurately determined by step S21 mentioned above, and the defective areas are accurately classified by step S22 mentioned above in order to develop unique process paths for different types of defective areas, making the cold spraying process more targeted and unique, meeting the process requirements of different areas, and improving the efficiency and quality of the spraying process.

[0072] In one embodiment, the above-mentioned step S22 further includes: For the point defect, a spray gun is driven to spray perpendicular to the center of the defective area, wherein preferably the point defect is a corrosion pit with a length and width of less than 5 mm; for the linear defect, the spray gun is driven to move along the longitudinal direction of the defective area, with a movement path of the spray gun remaining unchanged in the lateral direction, and the reciprocating times of the spray gun are determined based on the maximum depth of the corrosion pit, wherein preferably the linear defect is a corrosion pit with a length greater than or equal to 5 mm and a width of less than or equal to 5 mm; for the planar defect, the spray gun is driven to move along both the length and lateral directions of the defective area, and the reciprocating times of the spray gun are determined based on the maximum depth of the corrosion pit.wherein preferably the defects other than the point defect and the linear defect are planar defects, and the movement distance of the spray gun in the longitudinal direction of the defect and the movement distance in the width direction of the defect are adjusted based on the actual area size.

[0073] It should be noted that, in order to further improve the quality and efficiency of process operations, it is preferred to consider two or more than two point defects with a distance of no more than 5 mm between them as planar defects and to repair them by spraying according to the spraying process of a planar defect, and to consider two or more than two line defects with a distance of no more than 5 mm between them as planar defects and to repair them by spraying according to the spraying process of a planar defect.

[0074] In some embodiments, the above-mentioned step S3 further includes: using a milling cutter to machine the repair area based on an undamaged surface as a machining reference, and restoring related requirements, such as area size and roughness of the repaired area, according to the original drawing to ensure the accuracy of the parts.

[0075] The device provided in the present application for repairing damage to a mounting surface of an axle bearing body is capable of performing the method for repairing damage to a mounting surface of an axle bearing body as described above. The device for repairing damage to a mounting surface of an axle bearing body comprises a dimensional measuring system, a subtractive machining treatment system, a spraying system, and a subtractive restoration system. The dimensional measuring system is used to obtain a measurement of the size of a corrosion pit at a damaged location on a mounting surface of an axle bearing body. The subtractive machining treatment system is used to identify defective areas of the damaged location based on the measurement of the corrosion pit and to remove corrosion layers from the defective areas by applying a subtractive machining treatment.The spray system is used to classify the defective areas and then spray them accordingly based on the type of defect, creating appropriate repair areas. The subtractive restoration system is then used to perform subtractive rework on each repair area to restore the surface area to its original size.

[0076] By incorporating a size measurement system, a subtractive machining treatment system, a spraying system, and a subtractive restoration system, the device for repairing damage to a mounting surface of an axle bearing body is capable of performing the method for repairing damage to a mounting surface of an axle bearing body as described above, thereby possessing all the advantages of the method for repairing damage to a mounting surface of an axle bearing body as described above. The details are not elaborated here.

[0077] The following surface roughness is measured using a surface roughness tester. Design I

[0078] In embodiment I, an aluminum alloy powder is provided, and the manufacturing process for it is as follows: 1) 2.3% pure Mg powder, 5.3% pure Zn powder, 1.9% Nd powder, 0.9% graphite powder, 0.12% Zr powder, 2.2% Cu powder, 0.04% Ti powder, 0.04% Sr powder, and the remainder being Al powder, were selected based on their weight percent content and placed in a vacuum melting furnace. After complete melting, they were pulverized by argon sputtering at 800 °C and collected after cooling. 2) A sieve was used for powder classification to obtain aluminium alloy powder with a particle size of 10 µm to 60 µm.

[0079] Embodiment I also provides a method for improving the adhesion strength of a cold-sprayed high-pressure coating made of aluminum alloy, which includes: 1) Place the aluminium alloy powder produced in embodiment I into a vacuum drying oven for drying for 40 minutes at a drying temperature of 70 °C; 2) Removing the corrosion layer from the surface of the axle bearing body to be repaired, keeping it dry and then carrying out sandblasting, measuring the surface roughness (Ra) after sandblasting to be 7.6 µm; wherein the aluminium alloy powder, which was dried in step 1), was used for high-pressure cold spraying, wherein the high-pressure cold spraying air pressure was set to 5.0 MPa, the spray gun temperature was set to 400 °C, the spray gun speed was set to 300 mm / s and the spray gun angle was set to 90°; and 3) Performing a solution heat treatment on the repaired axle bearing body with a treatment temperature of 455 °C and a holding time of 35 minutes, and cooling it to 60 °C.

[0080] The micromorphology of the aluminum alloy powder produced in embodiment I under an electron microscope is described in Fig. 2 shown.

[0081] The aluminum alloy powder produced by the process according to embodiment I plays a role in refining and strengthening through the addition of rare earth elements, which refines the grain size, inhibits grain growth, and improves the mechanical strength of the powder particles. Simultaneously, the precipitation of the hard TiC phase further improves the strength of the powder particles.

[0082] In embodiment I, the repaired coating was applied by adjusting reasonable process parameters for cold spraying, and the repaired axle bearing body was hardened by solution heat treatment. Finally, the adhesion strength test was performed according to standard GBT 6396-2008. The coating's adhesion strength reached 126 MPa with a porosity of less than 0.2%. Design II

[0083] In embodiment II, an aluminum alloy powder is provided, and the manufacturing process for it is as follows: 1) 2.2% pure Mg powder, 6.5% pure Zn powder, 1.5% Nd powder, 1.0% graphite powder, 0.15% Zr powder, 2.0% Cu powder, 0.03% Ti powder, 0.05% Sr powder, and the remainder being Al powder, were selected based on their weight percent content and placed in a vacuum melting furnace. After complete melting, they were pulverized by argon sputtering at 800 °C and collected after cooling. 2) A sieve was used for powder classification to obtain aluminium alloy powder with a particle size of 15 µm to 55 µm.

[0084] Embodiment II also provides a method for improving the adhesion strength of a cold-sprayed high-pressure coating made of aluminum alloy, which includes: 1) Placing the aluminium alloy powder produced in embodiment II into a vacuum drying oven for drying for 1 hour at a drying temperature of 60 °C; 2) Removal of the corrosion layer from the surface of the axle bearing body to be repaired, keeping it dry and then carrying out sandblasting, whereby the surface roughness (Ra) is measured after sandblasting and is 5.8 µm; wherein the aluminium alloy powder, which was dried in step 1), was used for high-pressure cold spraying, wherein the high-pressure cold spraying air pressure was set to 5.5 MPa, the spray gun temperature was set to 500 °C, the spray gun speed was set to 300 mm / s and the spray gun angle was set to 70°; and 3) Performing a solution heat treatment on the repaired axle bearing body with a treatment temperature of 460 °C and a holding time of 40 minutes, and cooling it to 65 °C.

[0085] The aluminium alloy powder produced by the process according to embodiment II plays a role in refining and solidifying by adding rare earth elements, which refines the grain size, inhibits grain growth, creates the TiC solidification phase and improves the mechanical strength of the powder particles.

[0086] The micromorphology of the internal structure of the cold-sprayed repaired coating, produced in embodiment II under an electron microscope, is shown in Fig. 3 shown.

[0087] In embodiment II, the repaired coating was provided by adjusting appropriate process parameters for cold spraying, and the adhesion strength test was carried out according to standard GBT 6396-2008. The adhesion strength of the coating reached 130 MPa with a porosity of less than 0.2%. Design III

[0088] Embodiment III provides an aluminum alloy powder, and the manufacturing process for it is as follows: 1) 2.2% pure Mg powder, 6.5% pure Zn powder, 2.5% Nd powder, 1.0% graphite powder, 0.15% Zr powder, 2.0% Cu powder, 0.03% Ti powder, 0.06% Sr powder, and the remainder being Al powder, were selected based on their content in weight percent and were placed in a vacuum melting furnace. They were pulverized by argon sputtering at 800 °C after complete melting and collected after cooling. 2) A sieve was used for powder classification to obtain aluminium alloy powder with a particle size of 15 µm to 55 µm.

[0089] Embodiment III also provides a method for improving the adhesion strength of a cold-sprayed high-pressure aluminum alloy coating, which includes: 1) Place the aluminium alloy powder produced in embodiment III into a vacuum drying oven for drying for 1 hour at a drying temperature of 60 °C; 2) Removal of the corrosion layer from the surface of the axle bearing body to be repaired, keeping it dry and then carrying out sandblasting, whereby the surface roughness (Ra) is measured after sandblasting and is 5.8 µm; wherein the aluminium alloy powder, which was dried in step 1), was used for high-pressure cold spraying, wherein the high-pressure cold spraying air pressure was set to 5.5 MPa, the spray gun temperature was set to 500 °C, the spray gun speed was set to 300 mm / s and the spray gun angle was set to 90°; and 3) Performing a solution heat treatment on the repaired axle bearing body with a treatment temperature of 460 °C and a holding time of 40 minutes, and cooling it to 65 °C.

[0090] The aluminium alloy powder produced by the process according to embodiment III plays a role in refining and solidifying by adding rare earth elements, which refines the grain size, inhibits grain growth, creates the TiC solidification phase and improves the mechanical strength of the powder particles.

[0091] In embodiment III, the repaired coating was produced by adjusting reasonable process parameters for cold spraying, and the adhesion strength test was carried out according to standard GBT 6396-2008. The adhesion strength of the coating reached 135 MPa with a porosity of less than 0.2%. Design IV

[0092] Embodiment IV provides an aluminum alloy powder, and the manufacturing process for it is as follows: 1) 2.2% pure Mg powder, 6.5% pure Zn powder, 1.2% Nd powder, 1.0% graphite powder, 0.15% Zr powder, 2.0% Cu powder, 0.03% Ti powder, 0.02% Sr powder, and the remainder being Al powder, were selected based on their weight percent content and placed in a vacuum melting furnace. After complete melting, they were pulverized by argon sputtering at 800 °C and collected after cooling. 2) A sieve was used for powder classification to obtain aluminium alloy powder with a particle size of 15 µm to 55 µm.

[0093] Embodiment IV also provides a method for improving the adhesion strength of a cold-sprayed high-pressure coating made of aluminum alloy, which includes: 1) Placing the aluminium alloy powder produced in embodiment IV into a vacuum drying oven for drying for 1 hour at a drying temperature of 60 °C; 2) Removal of the corrosion layer from the surface of the axle bearing body to be repaired, keeping it dry and then carrying out sandblasting, whereby the surface roughness (Ra) is measured after sandblasting and is 5.8 µm; wherein the aluminium alloy powder, which was dried in step 1), was used for high-pressure cold spraying, wherein the high-pressure cold spraying air pressure was set to 5.5 MPa, the spray gun temperature was set to 500 °C, the spray gun speed was set to 300 mm / s and the spray gun angle was set to 90°; and 3) Performing a solution heat treatment on the repaired axle bearing body with a treatment temperature of 460 °C and a holding time of 40 minutes, and cooling it to 65 °C.

[0094] The aluminium alloy powder produced by the process according to embodiment IV plays a role in refining and solidifying by adding rare earth elements, which refines the grain size, inhibits grain growth, creates the TiC solidification phase and improves the mechanical strength of the powder particles.

[0095] In embodiment IV, the repaired coating was produced by adjusting reasonable process parameters for cold spraying, and the adhesion strength test was carried out according to standard GBT 6396-2008. The adhesion strength of the coating reached 125 MPa with a porosity of less than 0.2%. Comparative version I

[0096] Comparative embodiment I provides an aluminum alloy powder, and its manufacturing process is as follows: 1) 2.2% pure Mg powder, 6.5% pure Zn powder, 1.0% graphite powder, 0.15% Zr powder, 2.0% Cu powder, 0.03% Ti powder, and the remainder being Al powder, were selected based on their weight percent content and placed in a vacuum melting furnace. After complete melting, they were pulverized by argon sputtering at 800 °C and collected after cooling. 2) A sieve was used for powder classification to obtain aluminium alloy powder with a particle size of 15 µm to 55 µm.

[0097] Comparative embodiment I also provides a method for improving the adhesion strength of a cold-sprayed high-pressure coating made of aluminum alloy, which includes: 1) Placing the aluminium alloy powder produced in comparative embodiment I in a vacuum drying oven for drying for 1 hour at a drying temperature of 60 °C; 2) Removal of the corrosion layer from the surface of the axle bearing body to be repaired, keeping it dry and then carrying out sandblasting, whereby the surface roughness (Ra) is measured after sandblasting and is 5.8 µm; wherein the aluminium alloy powder which was dried in step 1) was used for high-pressure cold spraying, wherein the high-pressure cold spraying air pressure was set to 3.5 MPa, the spray gun temperature was set to 500 °C, the spray gun speed was set to 300 mm / s and the spray gun angle was set to 70°.

[0098] The micromorphology of the cold-sprayed repaired coating, produced in comparative embodiment I under an electron microscope, is shown in Fig. 4 shown.

[0099] The aluminum alloy powder, produced in the comparative formulation I, contains no rare earth elements; therefore, the powder particles are not sufficiently consolidated. No hard phase is formed, making it difficult to achieve a stable base strength. Consequently, a significant amount of pinning and anchoring effect cannot be achieved at the base interface. Additionally, the use of a lower gas pressure during spraying does not generate sufficient compressive stress within the coating. No solution heat treatment is performed after spraying, resulting in high porosity. The adhesion strength test was conducted according to standard GBT 6396-2008, and the coating's adhesion strength was only 48 MPa with a porosity of 0.8%. Comparative version II

[0100] Comparative embodiment II provides a method for improving the adhesion strength of a cold-sprayed high-pressure coating made of aluminum alloy, which includes: 1) Placing the aluminium alloy powder produced in embodiment II in a vacuum drying oven for drying for 1 hour at a drying temperature of 70 °C; 2) Removal of the corrosion layer from the surface of the axle bearing body to be repaired, keeping it dry and then carrying out sandblasting, whereby the surface roughness (Ra) is measured after sandblasting and is 5.8 µm; wherein the aluminium alloy powder, which was dried in step 1), was used for high-pressure cold spraying, wherein the high-pressure cold spraying air pressure was set to 3.5 MPa, the spray gun temperature was set to 500 °C, the spray gun speed was set to 300 mm / s and the spray gun angle was set to 70°; and 3) Performing a heat treatment on the repaired axle bearing body with a solution treatment temperature of 460 °C and a holding time of 40 minutes, and cooling it to 65 °C.

[0101] A lower spraying pressure was used in the comparative formulation II and has a limited acceleration effect on powder particles. The degree of plastic deformation of the particles is moderate. Insufficient compressive stress is generated within the coating, resulting in high porosity. The adhesion strength test was carried out according to standard GBT 6396-2008, and the coating's adhesion strength was only 47 MPa with a porosity of 1.2%. Comparative version III

[0102] Comparative embodiment III provides a method for improving the adhesion strength of a cold-sprayed high-pressure coating made of aluminum alloy, which includes: 1) Placing the aluminium alloy powder produced in embodiment II in a vacuum drying oven for drying for 1 hour at a drying temperature of 70 °C; 2) Removal of the corrosion layer from the surface of the axle bearing body to be repaired, keeping it dry and then carrying out sandblasting, whereby the surface roughness (Ra) is measured after sandblasting and is 5.8 µm; wherein the aluminium alloy powder which was dried in step 1) was used for high-pressure cold spraying, wherein the high-pressure cold spraying air pressure was set to 5.5 MPa, the spray gun temperature was set to 500 °C, the spray gun speed was set to 300 mm / s and the spray gun angle was set to 70°;

[0103] While a higher gas pressure was used for spraying in the comparative formulation III, no solution hardening was performed after spraying. Consequently, it was not possible to further eliminate internal defects, enhance interface element diffusion, or strengthen the bonding surface. The adhesion strength test was performed according to standard GBT 6396-2008, and the coating adhesion strength was 89 MPa with a porosity of 0.8%. Comparative version IV

[0104] Comparative formulation IV provides an aluminum alloy powder, and its manufacturing process is as follows: 1) 2.3% pure Mg powder, 5.3% pure Zn powder, 0.9% Nd powder, 0.9% graphite powder, 0.12% Zr powder, 2.2% Cu powder, 0.04% Ti powder, 0.01% Sr powder, and the remainder being Al powder, were selected based on their weight percent content and placed in a vacuum melting furnace. After complete melting, they were pulverized by argon sputtering at 800 °C and collected after cooling. 2) A sieve was used for powder classification to obtain aluminium alloy powder with a particle size of 15 µm to 55 µm.

[0105] The aluminum alloy powder produced in comparative embodiment IV was used to repair the axle bearing body in the same manner as in embodiment I. In the aluminum alloy powder produced in comparative embodiment IV, the addition amounts of Nd and Sr elements were reduced, and the hardening effect of the powder was impaired. The adhesion strength test was carried out according to standard GBT 6396-2008, and the coating adhesion strength was 103 MPa with a porosity of 0.3%. Comparative version V

[0106] Comparative version V provides an aluminum alloy powder, and its manufacturing process is as follows: 1) 2.3% pure Mg powder, 5.3% pure Zn powder, 3.0% Nd powder, 0.9% graphite powder, 0.12% Zr powder, 2.2% Cu powder, 0.04% Ti powder, 0.1% Sr powder, and the remainder being Al powder, were selected based on their weight percent content and placed in a vacuum melting furnace. After complete melting, they were pulverized by argon sputtering at 800 °C and collected after cooling. 2) A sieve was used for powder classification to obtain aluminium alloy powder with a particle size of 15 µm to 55 µm.

[0107] The aluminum alloy powder produced in comparative embodiment V was used to repair the axle bearing body in the same manner as in embodiment I. In the aluminum alloy powder produced in comparative embodiment V, the addition amounts of Nd and Sr elements were increased, which tended to lead to powder inclusions, increased porosity, and a loose internal structure of the coating. The adhesion strength test was carried out according to standard GBT 6396-2008, and the coating's adhesion strength was 92 MPa with a porosity of 0.7%.

[0108] In the description of the embodiments of the present application, it should be noted that the directional or positional relationships indicated by terms such as "center", "longitudinal", "side", "top", "bottom", "front", "rear", "left", "right", "vertical", "horizontal", "upper", "lower", "inside", "outside" are based on the orientations or positional relationships shown in the accompanying drawings and serve only for the ease of describing the embodiments of the present application and to simplify the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should therefore not be understood as limitations of the embodiments of the present application.Furthermore, the terms "first", "second" and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0109] In the description of the embodiments of the present application, it should be noted that the terms "connect" and "connected" should be understood in a broad sense unless otherwise clearly stated and specified. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium. The specific meanings of the foregoing terms in the embodiments of the present application may be understood by a person skilled in the art according to specific circumstances.

[0110] In the embodiments of the present application, a first feature that is "on" or "below" a second feature may refer to the first and second features being in direct contact or to the first and second features being in indirect contact through an intermediate medium, unless otherwise clearly stated and specified. Furthermore, a first feature that is "on," "above," and "on top" of a second feature may refer to the first feature being directly on or obliquely on the second feature, or simply to the first feature being horizontally higher than the second feature. A first feature that is "below," "underneath," and "lying beneath" a second feature may refer to the first feature being directly below or obliquely below the second feature, or simply to the first feature being horizontally lower than the second feature.

[0111] In the description of this specification, terms such as "one embodiment," "some embodiments," "example," "specific example," or "some embodiments" shall mean that the specific features, structures, materials, or properties described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of this application. In this description, the exemplary expressions of the foregoing terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials, or properties may be combined in any suitable manner in any one or more embodiments or examples.Furthermore, the person skilled in the art can combine and assign different embodiments or examples with features of different embodiments or examples described in this description without mutual contradiction.

[0112] Although the present application has been described in detail with general explanations and specific implementation schemes, it is obvious to the person skilled in the art that some modifications or improvements can be made to the present application.

[0113] Finally, it should be noted that the foregoing embodiments are used only to illustrate the solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, the person skilled in the art should understand that they may still modify the solutions described in the aforementioned embodiments or make equivalent substitutions for some of the features therein. However, these modifications or substitutions do not alter the nature of the corresponding solutions from the scope of the solutions of the embodiments of the present application. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CH 202211248277.7

[0001]

Claims

[1] A method for repairing damage to a mounting surface of an axle box, comprising the following steps: Obtaining a size measurement result of a corrosion pit at a damaged position on a mounting surface of an axle box body to determine defective areas of the damaged position, and removing corrosion layers of the defective areas by using a subtractive machining treatment; Performing a classification on the defective areas and spraying the defective areas accordingly based on a type of each of the defective areas to obtain corresponding repair areas; and Perform subtractive post-processing on each of the repair areas to restore a size of the mounting surface. [2] The method for repairing damage to a mounting surface of an axle box body according to claim 1, wherein the step of obtaining the size measurement result of the corrosion depression at the damaged position on the mounting surface of the axle box body to determine defective portions of the damaged position and removing corrosion layers of the defective portions by using a subtractive machining treatment comprises the following steps: Determining each of the defective regions of the damaged position based on a position of the corrosion depression, wherein each of the defective regions has at least one corrosion depression; Obtaining a maximum depth of the corrosion depression in the same defective area and an area of ​​a corresponding defective area to determine an area for a mechanical machining treatment; and Removing corrosion layers from each of the defective areas by using a subtractive machining treatment within each area for a mechanical machining treatment. [3] The method for repairing damage to a mounting surface of an axle box body according to claim 2, wherein the step of obtaining the maximum depth of the corrosion pit in the same defective area and the area of ​​the corresponding defective area to determine the area for a mechanical machining treatment comprises the following steps: Selecting a plurality of corrosion pits in the same defective area, and measuring a depth of each selected corrosion pit respectively using a depth calibrator, and obtaining the maximum depth of the corrosion pit by comparison; Measuring and calculating the area of ​​the defective area; and Determining the area for mechanical machining treatment based on the maximum depth of the corrosion pit and the area of ​​the defective area; wherein an area of ​​the machining treatment region is larger than the area of ​​the defective region, and a depth of the machining treatment region is not smaller than the maximum depth of the corrosion recess. [4] The method for repairing damage to a mounting surface of an axle box body according to claim 2, wherein after the step of removing corrosion layers from each of the defective areas by using a subtractive machining treatment within each area for a mechanical machining treatment, the method further comprises the steps of: Performing a fillet transition process on the defective areas subjected to the subtractive machining treatment; wherein an angle between a fillet of the defective region subjected to the fillet transition process and a base surface is not greater than 30°. [5] The method for repairing damage to a mounting surface of an axle box body according to claim 2, wherein the step of performing classification on the defective portions and spraying the defective portions respectively based on the type of each of the defective portions to obtain corresponding repair portions comprises the steps of: Obtaining a length and a width of each corrosion depression in the defective areas; Performing classification on the defective areas based on the length and width of each corrosion pit to determine types of the defective areas; wherein the types of the defective areas include a point defect, a line defect, and a flat defect; for the point defect, driving a spray gun to spray perpendicular to a center of the defective area; for the linear defect, driving a spray gun to move along a longitudinal direction of the defective area, wherein a movement path of the spray gun is unchanged in a width direction, and determining reciprocating movement times of the spray gun based on the maximum depth of the corrosion depression; and for the planar defect, driving a spray gun to move along a longitudinal direction and a width direction of the defective area, respectively, and determining reciprocating times of the spray gun based on the maximum depth of the corrosion recess. [6] The method for repairing damage to a mounting surface of an axle box according to claim 5, wherein the point defect is a corrosion pit having a length and width of both less than 5 mm; the linear defect is a corrosion pit having a length of more than or equal to 5 mm and a width of less than or equal to 5 mm; and defects other than the point defect and the linear defect are planar defects. [7] The method for repairing damage to a mounting surface of an axle box body according to any one of claims 1 to 6, wherein prior to the step of obtaining the size measurement result of the corrosion recess at the damaged position on the mounting surface of the axle box body to determine defective portions of the damaged position and removing corrosion layers of the defective portions by using a subtractive machining treatment, the method further comprises the following steps: Performing laser cleaning at the damaged position on the mounting surface; and Perform surface cleaning on the cleaned damaged position to expose the corrosion depression at the damaged position. [8] The method for repairing damage to a mounting surface of an axle box according to claim 7, wherein the step of performing laser cleaning at the damaged position on the mounting surface and performing surface cleaning at the cleaned damaged position to expose the corrosion recess at the damaged position comprises the following steps: Performing laser cleaning at the damaged position on the mounting surface using a laser cleaning system with a laser power of 50 W to 120 W for a cleaning time of 2 min to 5 min; and Perform surface cleaning at the cleaned damaged position using a high pressure air gun to expose the corrosion depression at the damaged position. [9] The method for repairing damage to a mounting surface of an axle box according to any one of claims 1 to 6, wherein prior to the step of performing classification on the defective areas and spraying the defective areas respectively based on the type of each of the defective areas to obtain corresponding repair areas, the method further comprises the following steps: Plugging all hole-shaped parts using a plug within the defective areas subjected to the subtractive machining treatment; Sandblasting of the defective areas that have undergone the subtractive machining treatment; and Preheating and spraying the defective areas that have been subjected to sandblasting. [10] The method for repairing damage to a mounting surface of an axle box body according to claim 9, wherein a surface roughness (Ra) of the defective portions subjected to the sandblasting is 5.0 µm to 7.6 µm. [11] The method for repairing damage to a mounting surface of an axle box according to claim 9, wherein process parameters of preheating and spraying comprise: Using aluminum alloy powder for preheating and spraying with a powder particle size of 10 µm to 60 µm, a powder drying temperature of 70 ± 5 °C, and a preheating and spraying time of 40 min to 60 min; wherein a spray gas used for preheating and spraying is 99.99% nitrogen; wherein a gas pressure of the spray gas is 3.5 MPa to 5.5 MPa; wherein a spraying distance for preheating and spraying is 5 mm to 20 mm; wherein an angle between a spray gun and a spray surface for preheating and spraying is not less than 60°. [12] An apparatus for repairing damage to a mounting surface of an axle box, which is capable of carrying out the method for repairing damage to a mounting surface of an axle box as claimed in any one of claims 1 to 11; the apparatus for repairing damage to a mounting surface of an axle box comprising: a size measuring system for obtaining a size measurement result of a corrosion pit at a damaged position on a mounting surface of an axle box; a subtractive machining treatment system for determining defective areas of the damaged position based on the size measurement result of the corrosion recess and for removing corrosion layers of the defective areas by using a subtractive machining treatment; a spraying system for performing classification on the defective areas and spraying the defective areas respectively based on a type of each of the defective areas to obtain corresponding repair areas; and a subtractive post-processing system for performing subtractive post-processing on each of the repair areas to restore a size of the mounting surface. [13] An aluminum alloy powder for use in the method for repairing damage to a mounting surface of an axle box according to claim 11, comprising the following components in weight percent: 3.2% to 7.8% Zn, 2.0% to 2.7% Mg, 1.5% to 2.9% Cu, 0.02% to 0.06% Ti, 0.3% to 1.5% C, 0.05% to 0.20% Zr, 1.0% to 2.8% Nd, 0.01% to 0.08% Sr, and the balance being Al. [14] The aluminum alloy powder according to claim 13, wherein the aluminum alloy powder comprises the following components in weight percent: 1.2% to 2.5% Nd and / or 0.02% to 0.06% Sr; preferably, the aluminum alloy powder comprises the following components in weight percent: 2.2% to 2.3% Mg, 5.3% to 6.5% Zn, 1.2% to 2.5% Nd, 0.9% to 1.0% C, 0.12% to 0.15% Zr, 2.0% to 2.2% Cu, 0.03% to 0.04% Ti, 0.02% to 0.06% Sr, and the remainder being Al. [15] A method for producing the aluminum alloy powder according to claim 13 or 14, comprising: 1) Mixing of components according to element proportions; 2) Heating and melting raw materials and performing atomization to produce powder; and 3) Drying and sieving the resulting powder to obtain aluminum alloy powder. [16] The method for producing the aluminum alloy powder according to claim 15, wherein the atomization for powder production uses argon atomization. [17] An aluminum alloy powder produced by the process according to claim 15 or 16. [18] Use of the aluminum alloy powder according to any one of claims 13 to 14 and 17 in the repair with aluminum alloy materials. [19] A method for improving the adhesion strength of a cold-sprayed high-pressure aluminum alloy coating, comprising: 1) Sandblasting an area to be repaired; 2) Using the aluminum alloy powder according to any one of claims 13 to 14 and 17 for cold spraying with high pressure; and 3) Performing a solution treatment on a workpiece that has been repaired by spraying. [20] The method according to claim 19, wherein a surface roughness (Ra) of the workpiece subjected to the sandblasting is 5.0 µm to 7.6 µm, preferably 5.8 µm to 7.6 µm. [21] The method according to claim 19 or 20, wherein the high pressure cold spraying is carried out at a temperature of 350°C to 500°C under a gas pressure of 4.5 MPa to 5.5 MPa; and / or the solution treatment is carried out at a temperature of 400°C to 500°C for a solution treatment time of 30 min to 60 min.

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