Surface strengthening method for metal covered edge of fan blade

Abstract

A fan blade metal edge covering surface strengthening method comprises the following steps that a sample piece is provided, an acid pickling test, a vibration finishing test and an inner and outer surface shot blasting test are carried out, and machining parameters and part sizes adopted in each procedure are determined through reverse deformation iteration. And according to the part size obtained through the test, shot blasting machining, outer surface vibration finishing machining and inner surface acid pickling machining are conducted on the metal edge covering blank, and a fan blade metal edge covering finished product is obtained. The outer surface of the fan blade metal edge covering finished product provided by the method meets the smooth finish requirement of the pneumatic performance of the fan blade, the inner surface meets the roughness requirement of the bonding strength, the fan blade metal edge covering finished product has good strength and fatigue performance, and the performance and reliability of an aero-engine can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the field of aeroengines, and in particular relates to a method for strengthening the metal edging surface of a fan blade. Background Art

[0002] Resin-based composite fan blades have the advantages of light weight, high efficiency, and strong applicability, and can effectively improve the thrust-to-weight ratio and fuel efficiency of aircraft engines. In order to improve the strength of the edge structure of the fan blades and improve the performance of resisting foreign body impact, some technical solutions will be composited with metal edging on the edge area of ​​the resin-based composite fan blades. As a reinforcing structure, the metal edging has an overall geometric structure that follows the curvature and twisting of the blades, and has a complex structure. At the same time, the outer side has higher smoothness requirements to meet the needs of aerodynamic performance, while the inner side has roughness requirements to meet the bonding strength requirements with the composite blade body. The existing surface strengthening process is difficult to fully meet the strengthening needs of the metal edging of fan blades, which affects the overall performance of the composite fan blades with metal edging. Therefore, providing a surface strengthening method for the metal edging of fan blades has high practical value for improving the aerodynamic efficiency and service life of fan blades. Summary of the invention

[0003] The object of the present invention is to provide a method for strengthening the surface of the metal edging of a fan blade, which improves the smoothness of the outer side of the metal edging while increasing the roughness of the inner side of the metal edging.

[0004] According to an embodiment of the present invention, a method for strengthening the surface of a fan blade metal edging is provided, and the method comprises the following steps: providing a fan blade metal edging sample, performing a pickling test on the inner surface of the fan blade metal edging sample, determining the pickling process parameters when the roughness of the inner surface of the fan blade metal edging meets the design requirements, and performing reverse deformation iteration according to the pickling deformation amount, so as to obtain the size of the pickled sample. Providing a pickled sample with the size of the pickled sample, performing a vibration finishing test on the outer surface of the pickled sample, determining the vibration finishing parameters when the roughness of the outer surface of the pickled sample meets the design requirements, and performing reverse deformation iteration according to the vibration finishing deformation amount, so as to obtain the size of the finishing sample. Providing a finishing sample with the size of the finishing sample, performing a shot peening test on the inner and outer surfaces of the finishing sample, respectively, determining the shot peening parameters when the residual stress of the inner and outer surfaces of the finishing sample meets the design requirements, and performing reverse deformation iteration according to the shot peening deformation amount, so as to obtain the size of the blank. A fan blade metal edging blank having the size of a blank is provided, and the fan blade metal edging blank is sequentially subjected to shot peening, outer surface vibration finishing and inner surface pickling, wherein the shot peening adopts the shot peening parameters, the outer surface vibration finishing adopts the vibration finishing parameters, and the pickling adopts the pickling process parameters, to obtain a fan blade metal edging finished product.

[0005] This method can be used to perform different surface strengthening treatments on the inner and outer surfaces of the fan blade metal edging, thereby forming different surface roughnesses while applying uniform residual compressive stress to the inner and outer surfaces, thereby meeting the aerodynamic performance requirements of the outer surface and the bonding strength requirements of the inner surface.

[0006] Furthermore, in some embodiments, in the shot peening step, when the outer surface of the fan blade metal edging blank is shot peened, an inner auxiliary mold is installed on the inner surface of the fan blade metal edging blank to provide support, and glass shots are used for compressed air shot peening or mechanical centrifugal shot peening strengthening; when the inner surface of the fan blade metal edging blank is shot peened, an outer auxiliary mold is installed on the outer surface of the fan blade metal edging blank to provide support, and steel shots are used for ultrasonic shot peening strengthening; the geometric structures of the inner auxiliary mold and the outer auxiliary mold are determined by shot peening tests on the polished samples.

[0007] Furthermore, in some embodiments, the outer auxiliary mold covers the outer surface of the fan blade metal edging blank and forms a closed end, and the closed end can abut on the support plane to form a closed cavity. The closed end can allow the outer auxiliary mold to abut on the oscillating device of the ultrasonic shot peening device, and the shot is enclosed in the closed cavity, thereby achieving uniform shot peening strengthening of the inner surface of the fan blade metal edging blank.

[0008] Furthermore, in some embodiments, the inner auxiliary mold and the outer auxiliary mold are formed by 3D printing. 3D printing has good dimensional accuracy, and the materials of the inner auxiliary mold and the outer auxiliary mold can be engineering plastics, photosensitive resin, ceramic or metal materials.

[0009] Furthermore, in some embodiments, in the vibration finishing step, a filling support mold is set on the inner surface of the fan blade metal edging blank, and a support protection frame is set on the outer side of the fan blade metal edging blank, and the support protection frame is configured as a rectangular frame, and the fan blade metal edging blank is accommodated in the support protection frame.

[0010] Furthermore, in some embodiments, the pickling step also includes the step of providing a protective layer on the outer surface of the fan blade metal edging blank.

[0011] Further, in some embodiments, in the pickling process, the composition of the pickling solution is 190-210 g / L HNO 3 and 45-55g / L HF, the balance is deionized water, and the pickling time is 15-30min.

[0012] Furthermore, in some embodiments, after the shot peening step and the vibration finishing step, an alkaline washing step is also included, in which the fan blade metal edging blank is cleaned using an alkaline cleaning agent.

[0013] Furthermore, in some embodiments, the alkaline cleaning agent includes a Turco5948 solution with a volume concentration of 20%-25% or an Ardrox6333A solution with a volume concentration of 10%-18%.

[0014] Furthermore, in some embodiments, the outer surface roughness of the finished metal edging product of the fan blade does not exceed Ra0.4 μm. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of the inner auxiliary mold and the outer auxiliary mold in one embodiment;

[0016] Figure 2 A schematic diagram of ultrasonic shot peening processing steps in one embodiment;

[0017] Figure 3 Schematic diagram of ultrasonic shot peening process steps in another embodiment.

[0018] The purpose of the above drawings is to explain the present invention in detail so that those skilled in the art can understand the technical concept of the present invention, but it is not intended to limit the present invention. For the sake of simplicity, the above drawings only schematically illustrate the structures related to the technical features of the present invention, and strictly draw the complete structure and all details in accordance with the actual proportion. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0020] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The phrase appearing in various locations in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive independent or alternative embodiments. Those skilled in the art should be able to understand that the embodiments herein may be combined with other embodiments without causing structural conflicts.

[0021] In the description of this article, unless otherwise clearly specified and limited, the technical terms "installed", "connected", "connected" and the like should be understood in a broad sense, which can be a movable connection, a fixed connection or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0022] In the description of this document, terms indicating orientation or positional relationships, such as "up", "down", "left", "right", "horizontal", "vertical", "height", "length", and "width", are intended to accurately describe the embodiments and simplify the description, but are not intended to limit the parts or structures involved to have a specific orientation, be installed or operate in a specific orientation, and should not be construed as a limitation on the embodiments in this document.

[0023] In the description of this article, the terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the quantity, specific order or primary and secondary relationship of the described technical features. In the description of this article, the meaning of "plurality" is at least two.

[0024] In order to enhance the strength of the leading edge of the composite fan blade and improve the ability to resist foreign body impact, the leading edge of the composite fan blade is usually attached with a metal sheet by bonding. The metal edging is usually a thin-walled structure with a V-shaped cross-section, and has a certain bending and twisting with the blade curvature. In order to ensure the degree of fit with the composite fan blade body, the dimensional accuracy of the metal edging is relatively high; at the same time, the outer surface of the metal edging is required to have a high degree of finish to meet the aerodynamic performance requirements of the fan blade; the inner surface of the metal edging is required to have a certain degree of roughness and cleanliness to meet the bonding strength requirements between the composite blade and the metal edging; the metal edging itself also needs to withstand high-frequency, long-cycle composite loads, so it needs to have good fatigue durability. Existing surface strengthening processes such as laser shock and shot peening are difficult to meet the complex surface performance requirements of metal edging, and are also prone to introduce processing deformation to affect the assembly accuracy of the metal edging. This results in the service life and performance of existing composite fan blades with metal edging being far from the ideal level.

[0025] In order to solve the above problems, an embodiment of the present invention provides a method for strengthening the surface of a fan blade metal edging. The method forms different surface properties on the inner and outer surfaces of the metal edging through a composite processing process of shot peening, vibration finishing and chemical pickling, respectively, to meet the performance requirements of the metal edging of a composite fan blade. The method comprises the following steps:

[0026] First, a processing parameter test was conducted.

[0027] Prepare metal edging samples according to the actual size of the metal edging of the fan blades, use tape or corrosion-resistant coatings (such as polyethylene layers, silicone layers or resin coatings) to cover and protect the outer surface of the metal edging samples, and perform pickling tests on the metal edging samples to determine the pickling process parameters when the inner surface roughness of the metal edging samples meets the design requirements. At the same time, measure the size change of the metal edging samples caused by pickling (mainly caused by the thinning of the metal edging samples caused by acid corrosion), perform reverse deformation iterations, and obtain the size of the pickling samples. Iterations can be verified for multiple rounds until the size of the sample with the size of the pickling sample after pickling is consistent with the metal edging of the finished fan blade.

[0028] The pickled sample is processed according to the size of the pickled sample, and a filling support mold is set in the V-shaped groove formed on the inner surface of the pickled sample. A vibration finishing test is performed, and the outer surface of the pickled sample is subjected to vibration finishing treatment to determine the vibration finishing processing parameters when the outer surface roughness meets the design requirements. The filling support mold is configured as a rigid support, and 3D printed ceramics, engineering plastics, photosensitive resins or metal materials can be used to prevent the pickled sample from being twisted and deformed during the vibration finishing process. In a preferred embodiment, a support protection frame is provided on the outside of the pickled sample during the vibration finishing process. The support protection frame is set as a rectangular frame as a whole, and the pickled sample is enclosed in the frame as a whole to prevent the pickled sample from being bumped and damaged during the vibration finishing process, which affects the finish of the outer surface. After the vibration finishing test is completed, the support protection frame and the filling support mold are removed, the processed size of the pickled sample is measured, and the reverse deformation iteration is performed to obtain the size of the finishing sample, that is, the size that the sample should have before the vibration finishing. Similarly, the reverse deformation iteration can be verified for multiple rounds to improve the accuracy of the size data of the finishing sample.

[0029] The polished sample is obtained by processing according to the size of the polished sample, and the outer auxiliary mold is processed according to the outer contour shape of the polished sample. The end of the outer auxiliary mold at least partially exceeds the edge of the V-shaped section of the polished sample to form a closed end in the same plane. The closed end is abutted against the oscillator of the ultrasonic shot peening device to form a closed cavity, so that the polished sample constitutes part of the inner wall of the closed cavity. Steel shots are loaded into the closed cavity, and the ultrasonic shot peening device is started to achieve ultrasonic shot peening surface strengthening of the inner surface of the polished sample, and the ultrasonic shot peening processing parameters are determined when the inner surface meets the surface residual stress design requirements. According to the contour shape of the inner surface of the polished sample, the inner auxiliary mold is manufactured and filled in the V-shaped groove structure of the polished sample to form a support. The outer surface of the polished sample is shot peened by conventional shot peening processes such as compressed air shot peening or mechanical centrifugal shot peening, and the shot peening processing parameters are determined when the outer surface meets the surface residual stress design requirements. After the shot peening process is completed, the dimensional change of the polished sample is measured, and the reverse deformation iteration is performed to obtain the size of the metal edging blank and the corresponding geometric structure information of the outer auxiliary mold and the inner auxiliary mold. The reverse deformation iteration can be performed multiple times to improve the accuracy of the blank size data. In some embodiments, the deformation of the metal edging after shot peening due to residual stress is not significant, and the outer auxiliary mold and the inner auxiliary mold adopt a conformal matching structure; in other embodiments, the metal edging after shot peening may produce a certain degree of warping due to residual stress, and the structure of the outer auxiliary mold and the inner auxiliary mold has a certain correction amount relative to the metal edging blank according to the reverse deformation iteration results.

[0030] Next, metal hemming is performed.

[0031] Prepare the fan blade metal edging blank according to the blank size determined in the previous steps. The manufacturing process can be carried out by casting, forging or 3D printing. According to the determined shot peening parameters, the outer auxiliary mold and the inner auxiliary mold determined by the test are used to perform ultrasonic shot peening on the inner surface of the fan blade metal edging blank, and conventional shot peening on the outer surface (specific methods include compressed air shot peening or mechanical centrifugal shot peening). After the shot peening is completed, a filling support mold is installed on one side of the inner surface, and the blank is installed as a whole into the support protection frame. Vibration finishing is performed according to the vibration finishing parameters determined by the test, and then alkaline cleaning is performed. Glue is pasted on the outer surface of the blank after alkaline cleaning, and the inner surface is pickled according to the pickling processing parameters determined by the test to roughen the inner surface, remove the iron pollution left by shot peening, and meet the surface roughness requirements required for bonding, so as to obtain the fan blade metal edging finished product.

[0032] In a preferred embodiment, the surface strengthening method of the fan blade metal edging is as follows:

[0033] First, determine the leading edge profile of the composite fan blade and design the corresponding metal edging. The metal edging section is a V-shaped groove, with the inside of the V-shaped groove as the inner surface and the outside of the V-shaped groove as the outer surface. Manufacture the metal edging sample, stick tape on the outer surface of the metal edging sample for protection, and then conduct a pickling test to determine the pickling process parameters when the inner surface roughness of the metal edging meets the design requirements. The pickling process parameters obtained from the experiment are shown in Table 1.

[0034]

[0035] Table 1 Pickling process parameters

[0036] According to the thinning amount of the metal edging caused by pickling, reverse deformation iteration is performed to obtain the pickling sample size after pickling that is consistent with the designed metal edging finished product.

[0037] Next, the pickling sample is prepared according to the size of the pickling sample. The V-shaped groove of the pickling sample is filled with a filling support mold made by 3D printing of photosensitive resin, and the pickling sample is placed in a supporting protection frame with a rectangular frame structure as a whole. The vibration finishing test is carried out to determine the vibration finishing process parameters when the outer surface of the pickling sample meets the roughness requirements, as shown in Table 2. The dimensional change of the pickling sample after vibration finishing is measured, and the reverse deformation iteration is performed to obtain the size of the finishing sample after vibration finishing that meets the size of the pickling sample.

[0038]

[0039] Table 2 Vibration finishing process parameters

[0040] like Figure 1 As shown, a polishing sample 1 with the size of a polishing sample is prepared, and an inner auxiliary mold 2 and an outer auxiliary mold 3 of a photosensitive resin material are manufactured by 3D printing technology according to the inner and outer surface sizes of the polishing sample 1. The inner auxiliary mold 2 and the outer auxiliary mold 3 are respectively matched with the polishing sample 1 to provide fixed support, wherein the end of the outer auxiliary mold 3 is formed with a closed end 8, and the closed ends 8 on both sides of the polishing sample 1 are in the same plane. The polishing sample 1 and the outer auxiliary mold 3 are combined together, as shown in FIG. Figure 2As shown, the closed end 8 can abut against the vibration device 6 of the ultrasonic vibration equipment to form a closed cavity 5 that encloses the polishing sample 1. The ultrasonic shot peening test is carried out using the steel shot peening 4 to determine the ultrasonic shot peening parameters when the residual compressive stress on the inner surface of the polishing sample 1 meets the design requirements. In a preferred embodiment, the diameter of the steel shot determined by the test is 0.2mm-2mm, and the ultrasonic frequency is 5kHz-30kHz. Due to the action of the vibration device 6, the steel shot peening 4 can quickly impact the inner surface of the polishing sample 1 to form a relatively uniform surface strengthening layer. During the shot peening process, the polishing sample 1 is constrained by the external auxiliary mold 3 and will not be deformed. Subsequently, the external auxiliary mold 3 is removed, and the internal auxiliary mold 2 is installed inside the polishing sample 1. The outer surface of the polishing sample 1 is subjected to a compressed air shot peening test using glass shot peening to determine the shot peening parameters when the residual compressive stress on the outer surface of the polishing sample 1 meets the design requirements. The test results are shown in Table 3. Specifically, the surface residual stress state obtained by shot peening can be obtained by microhardness testing or X-ray diffraction measurement. After removing the inner auxiliary mold 2, the deformation of the polished sample is measured, and the reverse deformation iteration is performed to obtain the size of the blank after shot peening that meets the size of the polished sample and the final size of the corresponding outer auxiliary mold and inner auxiliary mold.

[0041]

[0042] Table 3 External surface shot peening parameters

[0043] After the part size corresponding to each processing step is determined through experiments, the metal edging blank is forged according to the blank size, and the outer surface roughness of the forged metal edging blank does not exceed Ra0.4μm. An external auxiliary mold is installed on the outside of the metal edging blank, and the inner surface of the metal edging blank is shot peened according to the shot peening parameters determined by the aforementioned shot peening test.

[0044] In some embodiments, the metal edging blank is small in size and has a low degree of bending and twisting. The metal edging blank fixed on the external auxiliary mold can be turned upside down on the vibration device as a whole, thereby forming a complete containing space to accommodate the shot peening. Figure 2 Shot peening is achieved in the manner shown.

[0045] In other embodiments, the metal edging blank is relatively long, or has a high degree of bending and twisting, resulting in that some sections of the metal edging blank are far away from the surface of the vibration device or have a large deflection angle, making it difficult to buckle the entire metal edging on the vibration device while ensuring that the distance between each area of ​​the metal edging and the vibration device is within a reasonable range. In this case, the following method can be used: Figure 3In the manner shown, the inner surface of the metal edging blank is shot peened in sections: a processing cabin 7 with a through hole is set on the vibration device 6 of the ultrasonic vibration equipment, and the through hole size of the processing cabin 7 allows the external auxiliary mold to pass through. During the processing, the metal edging blank 1' together with the external auxiliary mold 3 is first sent into the processing cabin 7, and steel shot is loaded into the groove structure of the metal edging blank 1' located in the processing cabin 7, and a resin block (not shown) is filled in the groove structure of the metal edging blank 1' at the through hole position of the processing cabin 7 to block it, so as to prevent the shot from escaping along the groove structure during the ultrasonic shot peening process. After completing the shot peening of one area of ​​the metal edging blank 1', the position of the metal edging blank 1' is moved to perform shot peening of the next area. The closed end 8 of the external auxiliary mold 3 can exceed the end of the metal edging blank 1' by a certain distance to ensure that the metal edging blank 1' can still contain the shot when the bending and twisting are more obvious. In some embodiments, the upper surface of the vibrating device 6 may also be configured as a curved surface structure to adapt to the structure of the metal edging blank 1 ′.

[0046] After the shot peening of the inner surface is completed, the outer auxiliary mold is removed and the inner auxiliary mold is installed, and the outer surface of the metal edging blank is shot peened using the shot peening parameters determined by the above shot peening test.

[0047] After the shot peening process is completed, the inner auxiliary mold is removed, and the size of the metal edging blank is measured, and the size of the area where the size after shot peening is different from that of the polished sample is corrected. A filling support mold is installed in the V-groove structure of the metal edging blank, and a support protection frame is installed on the outside. The metal edging blank is subjected to vibration finishing according to the vibration finishing processing parameters determined by the above-mentioned vibration finishing test. The roughness of the outer surface of the metal edging blank after vibration finishing does not exceed Ra0.2μm.

[0048] In a preferred embodiment, after shot peening and vibration finishing, the metal edging blank is subjected to alkaline washing treatment with a Turco5948 solution with a volume concentration of 20%-25% or an Ardrox6333A solution with a volume concentration of 10%-18% respectively to clean the surface.

[0049] Measure the dimensions of the metal hemming blanks after vibration finishing, and correct the dimensions of the areas where the dimensions after vibration finishing deviate from the pickling sample. Paste tape or apply an anti-corrosion protective layer on the outer surface of the metal hemming blank, and perform pickling treatment using the pickling process parameters determined by the aforementioned pickling test to remove the iron contamination left by shot peening on the inner surface and further roughen the inner surface so that its roughness meets the bonding strength requirements. After pickling, perform dimensional inspection to obtain the metal hemming finished product.

[0050] The above method can provide a fan blade metal edging whose outer surface roughness meets the fan aerodynamic performance requirements and whose inner surface roughness meets the bonding strength requirements. While improving the aerodynamic performance and bonding strength of the composite material fan, the fatigue performance of the fan blade metal edging is further improved due to the introduction of a residual compressive stress layer on the inner and outer surfaces of the metal edging through shot peening.

[0051] The purpose of the above embodiments is to further explain the present invention in detail in conjunction with the accompanying drawings so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the present invention, the optimization or equivalent replacement of the part structure or method steps involved, and the combination of implementation methods in different embodiments without conflict of structure and principle, all fall within the protection scope of the present invention.

Claims

1. A method for strengthening the metal edging surface of a fan blade. It is characterized in that The following steps are involved: Providing a fan blade metal edging sample, performing a pickling test on the inner surface of the fan blade metal edging sample, determining the pickling process parameters that allow the roughness of the inner surface of the fan blade metal edging to meet the design requirements, and performing reverse deformation iteration according to the pickling deformation amount to obtain the size of the pickling sample; Providing a pickling sample with a pickling sample size, performing a vibration finishing test on the outer surface of the pickling sample, determining the vibration finishing parameters at which the roughness of the outer surface of the pickling sample meets the design requirements, and performing reverse deformation iteration according to the vibration finishing deformation amount to obtain the finishing sample size; Providing a polished sample with the size of a polished sample, performing shot peening tests on the inner surface and the outer surface of the polished sample respectively, determining the shot peening parameters when the residual stresses on the inner surface and the outer surface of the polished sample meet the design requirements, and performing reverse deformation iteration according to the shot peening deformation amount to obtain the size of the blank; A fan blade metal edging blank having the size of a blank is provided, and the fan blade metal edging blank is sequentially subjected to shot peening, outer surface vibration finishing and inner surface pickling, wherein the shot peening adopts the shot peening parameters, the outer surface vibration finishing adopts the vibration finishing parameters, and the pickling adopts the pickling process parameters, to obtain a fan blade metal edging finished product.

2. The fan blade metal edging surface strengthening method according to claim 1, It is characterized in that In the shot peening step, when the outer surface of the fan blade metal edging blank is shot peened, an inner auxiliary mold is installed on the inner surface of the fan blade metal edging blank to provide support, and glass shots are used for compressed air shot peening or mechanical centrifugal shot peening strengthening; when the inner surface of the fan blade metal edging blank is shot peened, an outer auxiliary mold is installed on the outer surface of the fan blade metal edging blank to provide support, and steel shots are used for ultrasonic shot peening strengthening; the geometric structures of the inner auxiliary mold and the outer auxiliary mold are determined by shot peening tests on the polished samples.

3. The fan blade metal edging surface strengthening method according to claim 2, It is characterized in that The outer auxiliary mold covers the outer surface of the fan blade metal edging blank and forms a closed end, and the closed end can abut on a supporting plane to form a closed cavity.

4. The fan blade metal edging surface strengthening method according to claim 2, It is characterized in that The inner auxiliary mold and the outer auxiliary mold are formed by 3D printing.

5. The fan blade metal edging surface strengthening method according to claim 1 or 2, It is characterized in that In the vibration finishing step, a filling support mold is set on the inner surface of the fan blade metal edging blank, and a support protection frame is set on the outer side of the fan blade metal edging blank. The support protection frame is configured as a rectangular frame, and the fan blade metal edging blank is accommodated in the support protection frame.

6. The fan blade metal edging surface strengthening method according to claim 1 or 2, It is characterized in that The pickling processing step also includes the step of providing a protective layer on the outer surface of the fan blade metal edging blank.

7. The fan blade metal edging surface strengthening method according to claim 6, It is characterized in that In the pickling process, the pickling solution is composed of 190-210 g / L HNO 3 and 45-55g / L HF, the balance is deionized water, and the pickling time is 15-30min.

8. The fan blade metal edging surface strengthening method according to claim 1 or 2, It is characterized in that After the shot peening process and the vibration finishing process, an alkaline washing process is also included, in which the fan blade metal edging blank is cleaned with an alkaline cleaning agent.

9. The fan blade metal edging surface strengthening method according to claim 8, It is characterized in that The alkaline cleaning agent includes a Turco5948 solution with a volume concentration of 20%-25% or an Ardrox6333A solution with a volume concentration of 10%-18%.

10. The fan blade metal edging surface strengthening method according to claim 1 or 2, It is characterized in that The outer surface roughness of the finished metal edging product of the fan blade does not exceed Ra0.2μm.

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