Method for preparing blade having uniform coating

Abstract

Disclosed in the present invention is a method for preparing a blade having a uniform coating, the method comprising the following steps: S1. assembling a blade to be coated (1) to a first positioning and clamping device; S2. sending the first positioning and clamping device (2) and said blade (1) into a coating furnace and adjusting same such that an included angle α is formed between a blade bottom surface (13) of said blade (1) and a horizontal direction of the coating furnace; S3. starting the coating furnace to complete the preparation of a first coating (51) on said blade (1); S4. taking out the first positioning and clamping device (2) and said blade (1), cleaning said blade (1), and then assembling said blade (1) to a second positioning and clamping device (3); S5. sending the second positioning and clamping device (3) and said blade (1) into the coating furnace and adjusting same such that an included angle β is formed between the blade bottom surface (13) of said blade (1) and a vertical direction of the coating furnace; and S6. starting the coating furnace to complete the preparation of a second coating (52) of said blade (1). The method has the advantages such as stability, reliability, uniform coating, and significantly improved blade cutting performance.

Description

A method for preparing a blade with uniform coating

[0001] Cross-reference to related applications

[0002] The present application is based on the Chinese patent application with the application date of "2024-06-28", the application number of "202410860094.3", and the invention name of "A method for preparing a blade with uniform coating", and claims the priority thereof, the whole content of the Chinese patent application is incorporated herein by reference as part of the present application. TECHNICAL FIELD

[0003] The present application mainly relates to the field of metal cutting tool forming, in particular to a method for preparing a blade with uniform coating. BACKGROUND

[0004] The metal cutting blade made of hard alloy material has large friction during cutting, and burr is easily generated during cutting, which can only be applied to parameter working conditions with low cutting speed, and has short service life. In the prior art, a coating process is usually used on the surface of the hard alloy blade, that is, a certain thickness of refractory compounds such as carbide, nitride and oxide is coated to serve as a protector, so that the surface of the cutting blade has the characteristics of high hardness, high wear resistance, high heat resistance and low friction coefficient, and the burr is eliminated, which can greatly improve the cutting performance and service life of the cutting blade.

[0005] However, in actual cutting processing applications, the wear amounts of the rake face and the relief face of the cutting blade are different. Sometimes, the cutting edge of the blade is invalid due to excessive wear of the rake face, and sometimes the cutting edge is invalid due to excessive wear of the relief face. There are two main reasons for the above problems: on the one hand, the material properties of the workpiece being processed affect it; on the other hand, the coating thickness of the rake face and the relief face of the cutting blade is not uniform.

[0006] In the prior art, the operation of preparing the coating of the blade usually fixes a plurality of cutting blades by using a positioning device, and then the blade is conveyed to a coating furnace for coating preparation. If a multi-layer coating with different materials in each layer needs to be prepared, the method in the prior art is to change the coating material sprayed by the coating furnace, and to prepare the coating layer by layer. Since the coating material spraying source of the physical coating furnace is located on the side wall of the coating furnace, the spraying direction of the coating material is horizontal, and the rake face and the relief face of the coating blade are not in the same plane, the angles of the rake face and the relief face with the spraying direction of the coating material are different, and when a certain layer of coating is prepared, the coating thickness on the rake face and the relief face is obviously uneven. If multi-layer coating is prepared, the overall coating thickness difference of the rake face and the relief face is more obvious, that is, the coating thickness of the rake face and the relief face is uneven, which affects the cutting performance of the cutting blade. SUMMARY

[0007] The technical problem solved by the present application is to overcome the deficiencies of the prior art, and provide a method for preparing a blade with uniform coating, which is stable and reliable, has uniform coating, and can significantly improve the cutting performance of the blade.

[0008] To solve the above technical problems, the present application adopts the following technical solutions:

[0009] A method for preparing a blade with uniform coating, comprising the following steps:

[0010] S1, assembling the blade to be coated to a first positioning and clamping device;

[0011] S2, sending the first positioning and clamping device and the blade to be coated into a coating furnace and adjusting, so that the blade bottom surface of the blade to be coated forms an angle α with the horizontal direction of the coating furnace;

[0012] S3, starting the coating furnace to complete the preparation of the first coating of the blade to be coated;

[0013] S4, taking out the first positioning and clamping device and the blade to be coated, cleaning the blade to be coated, and then assembling the blade to be coated to a second positioning and clamping device;

[0014] S5, sending the second positioning and clamping device and the blade to be coated into the coating furnace and adjusting, so that the blade bottom surface of the blade to be coated forms an angle β with the vertical direction of the coating furnace;

[0015] S6, starting the coating furnace to complete the preparation of the second coating of the blade to be coated;

[0016] In steps S2 and S5, the angles α and β should satisfy: 0≤α≤30° and 0≤β≤30°, or satisfy: 60°≤α≤90° and 60°≤β≤90°, and also satisfy: 0.8β≤α≤1.2β.

[0017] In some embodiments of the present application:

[0018] The angles α and β should satisfy: α=0 and β=0.

[0019] In the step S4, before cleaning the blade to be coated, jet processing is performed on the cutting edge of the blade to be coated, using corundum particles with a particle size of 120-150 mesh, and the jet processing time is 1-3 minutes.

[0020] In the step S3, the first coating is formed on both the rake face and the flank face of the blade to be coated, and in the step S6, the second coating is formed on both the rake face and the flank face of the blade to be coated.

[0021] The maximum total thickness of the coating on the rake face is Y1, and the maximum total thickness of the coating on the flank face is Y2, which should satisfy: 0≤Y1-Y2≤1μm.

[0022] The minimum total thickness of the coating on the rake face is Y1', and the minimum total thickness of the coating on the flank face is Y2', which should satisfy: 0≤Y1-Y1'≤1μm, 0≤Y2-Y2'≤1μm.

[0023] The maximum thickness of the first coating on the rake face is X1, and the maximum thickness of the second coating is X2, and the maximum thickness of the first coating on the flank face is X1', and the maximum thickness of the second coating is X2', which should satisfy: 1μm≤X1-X2≤3μm, 1μm≤X2'-X1'≤3μm.

[0024] The maximum thickness of the first coating on the rake face is X1, and the maximum thickness of the second coating is X2, and the maximum thickness of the first coating on the flank face is X1', and the maximum thickness of the second coating is X2', which should satisfy: 1μm≤X2-X1≤3μm, 1μm≤X1'-X2'≤3μm.

[0025] The first positioning and clamping device and / or the second positioning and clamping device comprises a bottom plate capable of forming a partially covered coating on the flank face and a cover plate capable of forming a partially covered coating on the rake face.

[0026] Compared with the prior art, the present application has the advantages of:

[0027] The method for preparing the knife blade with uniform coating of the present application adopts the first positioning and clamping device to clamp and position the knife blade to be coated, so that the position and angle of the knife blade to be coated in the coating furnace can be adjusted, and the blade bottom surface of the knife blade to be coated forms an angle a with the horizontal direction of the coating furnace. First, a uniform first coating is formed on the rake face and the relief face. Since the angles of the rake face and the relief face with the horizontal coating spraying direction are different, the thickness of the first coating on the rake face and the relief face is also different (the thickness of the first coating on the rake face is X1, and the thickness of the first coating on the relief face is X1'). Then, the second positioning and clamping device is adopted to clamp and position the knife blade to be coated, so that the blade bottom surface of the knife blade to be coated forms an angle β with the vertical direction of the coating furnace. The second coating is formed on the rake face and the relief face. The thickness of the second coating on the rake face and the relief face is also different (the thickness of the second coating on the rake face is X2, and the thickness of the first coating on the relief face is X2'). Since the angle a and the angle β satisfy 0≤a≤30° and 0≤β≤30°, or satisfy 60°≤a≤90° and 60°≤β≤90°, and satisfy 0.8β≤a≤1.2β (that is, the values of a and β are relatively close, which is equivalent to the positions of the rake face 11 and the relief face 12 being interchanged in the preparation of the two coatings), the overall thickness of the two coatings on the rake face (X1+X2) and the overall thickness of the two coatings on the relief face (X1'+X2') can be basically the same. Since the blade bottom surface of the knife blade to be coated has the angle a with the horizontal direction of the coating furnace when the first coating is prepared, the particle density of the coating particles sprayed by the coating furnace and deposited on the rake face and the relief face is reduced. When the thickness of the first coating reaches the set value, the thickness of the first coating on the rake face is more uniform, and the thickness of the first coating on the relief face is also more uniform. Similarly, the thickness of the second coating on the rake face is more uniform, and the thickness of the second coating on the relief face is also more uniform. Therefore, the overall thickness of the coating at each position on the rake face is more uniform, and the overall thickness of the coating at each position on the relief face is also more uniform. Thus, the problem of uneven coating thickness caused by the different angles of the rake face and the relief face with the coating spraying direction in the prior art is eliminated. The coating formed on the rake face is more uniform and stable, and the coating formed on the relief face is also more uniform and stable. At the same time, the coating thickness of the rake face and the relief face can also be uniform and consistent, the tensile and compressive stress between the coatings of the knife blade is small, and the combination of different coatings can also be realized. The prepared knife blade has good impact resistance and wear resistance, and the cutting performance of the knife blade is improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic view of the coating device adopted in the method for preparing the knife blade with uniform coating of the present application;

[0029] Figure 2 is a schematic view of the first positioning and clamping device of the method for preparing the knife blade with uniform coating of the present application;

[0030] Fig. 3 is a schematic view of a second positioning and clamping device used in the method for manufacturing a blade with uniform coating according to the present application;

[0031] Fig. 4 is a schematic view of the first coating prepared in the method for manufacturing a blade with uniform coating according to the present application;

[0032] Fig. 5 is a schematic view of the first coating prepared in the method for manufacturing a blade with uniform coating according to the present application (enlarged);

[0033] Fig. 6 is a schematic view of the second coating prepared in the method for manufacturing a blade with uniform coating according to the present application;

[0034] Fig. 7 is a schematic view of the first coating prepared in the method for manufacturing a blade with uniform coating according to the present application (enlarged);

[0035] Fig. 8 is a schematic view of the rake face and the flank face of the blade prepared in the method for manufacturing a blade with uniform coating according to the present application with complete coverage of the coating;

[0036] Fig. 9 is an enlarged view of A in Fig. 8;

[0037] Fig. 10 is a schematic view of the rake face and the flank face of the blade prepared in the method for manufacturing a blade with uniform coating according to the present application with incomplete coverage of the coating;

[0038] Fig. 11 is a schematic view of the base plate and the cover plate of the coating device used in the method for manufacturing a blade with uniform coating according to the present application.

[0039] In the drawings, the following reference numerals denote: 1, blade to be coated; 11, rake face; 12, flank face; 13, bottom surface of the blade; 2, first positioning and clamping device; 3, second positioning and clamping device; 51, first coating; 52, second coating; 6, base plate; 61, side recess; 7, cover plate; 71, top recess; 8, coating furnace; 81, side wall of the coating furnace.

DETAILED DESCRIPTION

[0040] The present application will be further described in detail below with reference to the accompanying drawings and specific examples.

[0041] In the description of the present application, it should be noted that the terms "upper", "horizontal", "inner", "outer", "top", "bottom" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0042] Fig. 1 to Fig. 11 show the coating device used in the method for preparing the uniformly coated blade of the present application, which mainly comprises a coating furnace 8, a first positioning and clamping device 2 and a second positioning and clamping device 3, and the method for preparing the uniformly coated blade of the present application comprises the following steps:

[0043] S1, assembling the blade to be coated 1 to the first positioning and clamping device 2;

[0044] S2, sending the first positioning and clamping device 2 and the blade to be coated 1 into the coating furnace and adjusting so that the blade bottom surface 13 of the blade to be coated 1 forms an angle a with the horizontal direction of the coating furnace;

[0045] S3, starting the coating furnace to complete the preparation of the first coating 51 of the blade to be coated 1;

[0046] S4, taking out the first positioning and clamping device 2 and the blade to be coated 1, cleaning the blade to be coated 1, and then assembling the blade to be coated 1 to the second positioning and clamping device 3;

[0047] S5, sending the second positioning and clamping device 3 and the blade to be coated 1 into the coating furnace and adjusting so that the blade bottom surface 13 of the blade to be coated 1 forms an angle β with the vertical direction of the coating furnace;

[0048] S6, starting the coating furnace to complete the preparation of the second coating 52 of the blade to be coated 1;

[0049] Wherein, the angle a and the angle β in steps S2 and S5 should satisfy: 0≤a≤30° and 0≤β≤30°, and also satisfy: 0.8β≤a≤1.2β.

[0050] The method for preparing the knife blade with uniform coating of the present application first adopts the first positioning and clamping device 2 to clamp and position the to-be-coated knife blade 1, so that the position and angle of the to-be-coated knife blade 1 in the coating furnace 8 can be adjusted, and the blade bottom surface 13 of the to-be-coated knife blade 1 forms an included angle a with the horizontal direction of the coating furnace 8, a uniform first coating 51 is first formed on the rake surface 11 and the flank surface 12, and due to the fact that the included angles of the rake surface 11 and the flank surface 12 with the horizontal coating spraying direction are different, the thicknesses of the first coating 51 on the rake surface 11 and the flank surface 12 are also different (the thickness of the first coating on the rake surface is X1, and the thickness of the first coating on the flank surface is X1'), then the second positioning and clamping device 3 is adopted to clamp and position the to-be-coated knife blade 1, so that the blade bottom surface 13 of the to-be-coated knife blade 1 forms an included angle b with the vertical direction of the coating furnace 8, a second coating 52 is formed on the rake surface 11 and the flank surface 12, and based on the same reason, the thicknesses of the second coating 52 on the rake surface 11 and the flank surface 12 are also different (the thickness of the second coating on the rake surface is X2, and the thickness of the first coating on the flank surface is X2'), and due to the fact that the included angles a and b satisfy 0.8b≤a≤1.2b (that is, the values of a and b are relatively close, which is equivalent to the positions of the rake surface 11 and the flank surface 12 being interchanged during the preparation of the two coatings), the overall thickness (X1+X2) of the two coatings on the rake surface 11 and the overall thickness (X1'+X2') of the two coatings on the flank surface 12 can be basically the same, and due to the fact that during the preparation of the first coating 51, the blade bottom surface 13 of the to-be-coated knife blade 1 has the included angle a with the horizontal direction of the coating furnace 8, 0≤a≤30°, compared with the prior art, the particle density of the same number of coating particles sprayed by the coating furnace 8 and deposited on the rake surface 11 and the flank surface 12 is reduced, when the thickness of the first coating 51 reaches the set value, the thickness of the first coating 51 on the rake surface 11 is more uniform, and the thickness of the first coating 51 on the flank surface 12 is also more uniform, and similarly, the thickness of the second coating 52 on the rake surface 11 is more uniform, and the thickness of the second coating 52 on the flank surface 12 is also more uniform, thereby the overall thickness of the coating at each position of the rake surface 11 is more uniform, and the overall thickness of the coating at each position of the flank surface 12 is also more uniform. Thus, the problem of non-uniform coating thickness caused by the different angles of the rake surface 11 and the flank surface 12 with the coating spraying direction in the prior art is eliminated, the coating formed on the rake surface 11 is more uniform and stable, the coating formed on the flank surface 12 is also more uniform and stable, at the same time, the coating thicknesses of the rake surface 11 and the flank surface 12 can also be uniform and consistent, the tensile and compressive stresses between the coatings of the knife blade are small, the combination of different coatings can also be realized, the prepared knife blade coating has good impact resistance and wear resistance, and the cutting performance of the knife blade is improved.

[0051] As shown in FIG. 2, FIG. 4 and FIG. 5, the first positioning and clamping device 2 is used to clamp and position the blade to be coated 1 to prepare the first coating 51: a plurality of coating spraying devices are arranged on the side wall 81 of the coating furnace, and the coating material is sprayed horizontally. In FIG. 2, the first positioning and clamping device 2 is in state B, C and D, which all meet the requirement of the present application that the blade bottom surface 13 of the blade to be coated 1 forms an angle a with the horizontal direction of the coating furnace 8. As shown in FIG. 4 and FIG. 5 (the arrows in the figures represent the coating spraying direction), after the preparation of the first coating 51 is completed, the thickness of the first coating 51 on the rake surface 11 is X1, and the thickness of the first coating on the flank surface 12 is X1'. Due to the arrangement of the angle a satisfying 0≤a≤30° (in the present embodiment, a=13°), the particle density of the coating particles deposited on the rake surface 11 and the flank surface 12 decreases with the same number of coating particles sprayed by the coating spraying device. When the thickness of the first coating 51 reaches the set value, the thickness of the first coating 51 on the rake surface 11 is more uniform, and the thickness of the first coating 51 on the flank surface 12 is also more uniform.

[0052] As shown in FIG. 3, FIG. 6 and FIG. 7, the second positioning and clamping device 3 is used to clamp and position the blade to be coated 1 whose first coating 51 has been prepared to prepare the second coating 52: in FIG. 3, the second positioning and clamping device 3 is in state E, F and G, which all meet the requirement of the present application that the blade bottom surface 13 of the blade to be coated 1 forms an angle β with the horizontal direction of the coating furnace 8. As shown in FIG. 6 and FIG. 7 (the arrows in the figures represent the coating spraying direction), after the preparation of the second coating 52 is completed, the thickness of the second coating 52 on the rake surface 11 is X2, and the thickness of the second coating on the flank surface 12 is X2'. Since the values of a and β are relatively close, it is equivalent to the positions of the rake surface 11 and the flank surface 12 being interchanged during the preparation of the two coatings (see the rake surface and the flank surface in FIG. 4 and FIG. 6), so that the overall thickness of the two coatings (X1+X2) on the rake surface 11 and the overall thickness of the two coatings (X1'+X2') on the flank surface 12 can be basically the same. Due to the arrangement of the angle β satisfying 0≤β≤30° (in the present embodiment, β=13°), the particle density of the coating particles deposited on the rake surface 11 and the flank surface 12 decreases with the same number of coating particles sprayed by the coating spraying device. When the thickness of the second coating 52 reaches the set value, the thickness of the second coating 52 on the rake surface 11 is more uniform, and the thickness of the second coating 52 on the flank surface 12 is also more uniform.

[0053] In addition to the present embodiment, the angle a and the angle β can also be arranged to satisfy 60°≤a≤90° and 60°≤β≤90°, which can also achieve the above technical effects.

[0054] If the included angle α and the included angle β are set as α=0 and β=0, the number of the blades prepared by one coating can be maximized and the positioning difficulty of the blades and the positioning clamping device can be reduced under the condition that the space of the coating preparation area in the coating furnace 8 is limited, the production efficiency of the blades is greatly improved, and the overall thickness of the coating on the rake face 11 and the relief face 12 can be basically the same through twice coating preparation, and the coating is uniform and stable.

[0055] In the embodiment, the blade edge of the blade to be coated 1 is subjected to the jet processing before the blade to be coated 1 is cleaned in step S4, and the corundum particles with the granularity of 120-150 meshes are used, and the jet time is 1-3 minutes.

[0056] In the embodiment, the first coating 51 is formed on the rake face 11 and the relief face 12 of the blade to be coated 1 in step S3, and the second coating 52 is formed on the rake face 11 and the relief face 12 of the blade to be coated 1 in step S6.

[0057] In order to ensure the coating performance, the maximum total thickness of the coating on the rake face 11 is Y1, the maximum total thickness of the coating on the relief face 12 is Y2, the minimum total thickness of the coating on the rake face 11 is Y1', and the minimum total thickness of the coating on the relief face 12 is Y2', which should satisfy: 0≤Y1-Y2≤1μm, 0≤Y1-Y1'≤1μm, and 0≤Y2-Y2'≤1μm, in the embodiment, Y1=Y2=5μm, Y1'=4.9μm, and Y2'=4.9μm.

[0058] In the embodiment, the thickness of the first coating 51 on the rake face 11 is X1, the thickness of the second coating 52 is X2, the thickness of the first coating 51 on the relief face 12 is X1', and the thickness of the second coating 52 is X2', in order to ensure the coating performance, which should satisfy: 1μm≤X1-X2≤3μm and 1μm≤X2'-X1'≤3μm, in the embodiment, X1=3μm, X2=2μm, X2'=3μm, and X1'=2μm.

[0059] In addition to the above embodiment, the thickness of the first coating 51 on the rake face 11 is X1, the thickness of the second coating 52 is X2, the thickness of the first coating 51 on the relief face 12 is X1', and the thickness of the second coating 52 is X2', which should satisfy: 1μm≤X2-X1≤3μm and 1μm≤X1'-X2'≤3μm.

[0060] In the coating device used in the method for preparing the blade with uniform coating in the embodiment, the first positioning clamping device 2 can be magnetic or can be a hook for fixing the blade to be coated 1.

[0061] In the embodiment, the first positioning and clamping device 2 and the second positioning and clamping device 3 include a base plate 6 capable of forming the incomplete coating on the clearance face 12 and a cover plate 7 capable of forming the incomplete coating on the rake face 11, the base plate 6 is provided with a side recess 61, and the cover plate 7 is provided with a top recess 71. The incomplete coating on the clearance face 12 of the blade to be coated 1 can be formed by mounting the blade to be coated 1 in the base plate 6, and the incomplete coating on the rake face 11 of the blade to be coated 1 can be formed by mounting the cover plate 7 on the rake face 11 of the blade to be coated 1. The first coating 51 and the second coating 52 can both be set as incomplete coatings.

[0062] In addition to the embodiment, the first positioning and clamping device 2 can include a base plate 6 capable of forming the incomplete coating on the clearance face 12 and a cover plate 7 capable of forming the incomplete coating on the rake face 11, or the second positioning and clamping device 3 can include a base plate 6 capable of forming the incomplete coating on the clearance face 12 and a cover plate 7 capable of forming the incomplete coating on the rake face 11.

[0063] In the embodiment, in order to facilitate the control of the spraying direction of the coating material and to prepare the incomplete coating, the coating furnace 8 is a physical coating furnace.

[0064] Although the present application has been disclosed in the preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art can make many possible changes and modifications to the technical solutions of the present application or modify equivalent embodiments with equivalent changes without departing from the scope of the technical solutions of the present application by using the technical contents disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the content of the technical solutions of the present application shall fall within the scope of protection of the technical solutions of the present application.

Claims

1. A method for preparing a cutting blade with a uniform coating, characterized in that, Includes the following steps: S1. Assemble the blade (1) to be coated onto the first positioning and clamping device (2); S2. The first positioning clamping device (2) and the blade to be coated (1) are sent into the coating furnace and adjusted so that the bottom surface (13) of the blade to be coated (1) forms an angle α with the horizontal direction of the coating furnace. S3. Start the coating furnace to complete the preparation of the first coating (51) on the blade (1) to be coated; S4. Take out the first positioning clamping device (2) and the blade to be coated (1), clean the blade to be coated (1), and then assemble the blade to be coated (1) onto the second positioning clamping device (3). S5. The second positioning clamping device (3) and the blade to be coated (1) are sent into the coating furnace and adjusted so that the bottom surface (13) of the blade to be coated (1) forms an angle β with the vertical direction of the coating furnace. S6. Start the coating furnace to complete the preparation of the second coating (52) on the blade (1) to be coated; In steps S2 and S5, the included angles α and β should satisfy: 0 ≤ α ≤ 30° and 0 ≤ β ≤ 30°, or satisfy: 60° ≤ α ≤ 90° and 60° ≤ β ≤ 90°, and should also satisfy: 0.8β ≤ α ≤ 1.2β.

2. The method for preparing a blade with a uniform coating according to claim 1, characterized in that: The included angles α and β satisfy: α = 0, β = 0.

3. The method for preparing a blade with a uniform coating according to claim 1 or 2, characterized in that: In step S4, before cleaning the blade (1) to be coated, the cutting edge of the blade (1) to be coated is subjected to jet treatment using corundum particles with a particle size of 120-150 mesh and a jet time of 1-3 minutes.

4. The method for preparing a blade with a uniform coating according to claim 1 or 2, characterized in that: In step S3, a first coating (51) is formed on both the rake face (11) and the flank face (12) of the insert (1) to be coated. In step S6, a second coating (52) is formed on both the rake face (11) and the flank face (12) of the insert (1) to be coated.

5. The method for preparing a blade with a uniform coating according to claim 4, characterized in that: The maximum total thickness of the coating on the front face (11) is Y1, and the maximum total thickness of the coating on the back face (12) is Y2, which should satisfy: 0≤Y1-Y2≤1μm.

6. The method for preparing a blade with a uniform coating according to claim 5, characterized in that: The minimum total thickness of the coating on the front face (11) is Y1', and the minimum total thickness of the coating on the back face (12) is Y2', which should satisfy: 0≤Y1-Y1'≤1μm, 0≤Y2-Y2'≤1μm.

7. The method for preparing a blade with a uniform coating according to claim 6, characterized in that: The maximum thickness of the first coating (51) on the front face (11) is X1, the maximum thickness of the second coating (52) is X2, the maximum thickness of the first coating (51) on the back face (12) is X1', and the maximum thickness of the second coating (52) is X2'. It should satisfy: 1μm≤X1-X2≤3μm, 1μm≤X2'-X1'≤3μm.

8. The method for preparing a blade with a uniform coating according to claim 6, characterized in that: The maximum thickness of the first coating (51) on the front face (11) is X1, the maximum thickness of the second coating (52) is X2, the maximum thickness of the first coating (51) on the back face (12) is X1', and the maximum thickness of the second coating (52) is X2'. The following conditions must be met: 1μm≤X2-X1≤3μm, 1μm≤X1'-X2'≤3μm.

9. The method for preparing a blade with a uniform coating according to claim 1 or 2, characterized in that: The first positioning clamping device (2) and / or the second positioning clamping device (3) include a chassis (6) that can form a coating that does not completely cover the rear blade face (12) and a cover plate (7) that can form a coating that does not completely cover the front blade face (11).

10. The method for preparing a blade with a uniform coating according to claim 1 or 2, characterized in that: The coating furnace is a physical coating furnace.

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