An erosion-resistant blade tenon and its preparation method and application

Abstract

The present invention provides an erosion-resistant blade tenon, and a preparation method and application thereof. The erosion-resistant blade tenon is in an I-shaped structure as a whole, and the top of the I-shaped structure is the tail of the tenon, which is in the shape of an inverted triangle; the bottom of the I-shaped structure is a convex tenon, and the two ends of the tenon are arc-shaped protrusions; the central column part of the I-shaped structure includes: an arc-shaped buffer area connected to the tail of the tenon, a lower arrow area composed of lines L1, L2, and L3, and a smooth transition area composed of line L3 and the convex tenon. A plurality of grooves are provided on the side of the arc-shaped buffer area, which are symmetrically distributed in the horizontal direction with the outer vertex of the arc-shaped buffer area as the center. A double-layer composite coating of PPS-PTFE is sprayed on the entire surface of the tenon, and an additional layer of PPS-PTFE-GO coating is sprayed on the side of the tenon part. The blade tenon prepared by the present invention has excellent erosion resistance, wear resistance, hydrophobic and anti-icing effect, and lubrication ability, and can be used as a tenon for aircraft engine fan blades to cope with various service environments.

Description

Technical Field

[0001] The present invention belongs to the field of anti-erosion, and in particular relates to an anti-erosion blade tenon and a preparation method thereof. Background Art

[0002] With the rapid development of transportation, airplanes have become an indispensable tool for long-distance travel. The engine that powers an aircraft is crucial to its operation. Aircraft rely on numerous blades to compress and expand air to ensure proper flight, making the fan blade tenon a crucial component.

[0003] The blade tenons rotate at high speed during normal service. When the aircraft takes off and lands, the flying sand and gravel will collide with the moving blade tenons. During the flight, they are also affected by the resistance of high-speed operation. Not only that, they are also exposed to the impact of high-pressure corrosive gas.

[0004] Furthermore, the blade components themselves are complex to manufacture, requiring high machining difficulty, and are numerous in number. Various erosion-induced surface damage can, over time, cause irreversible damage to the engine fan blades. The blade tenon, as the connection between the blade and the engine rotor, is particularly susceptible to this damage, severely impacting performance. Furthermore, components severely aged by erosion wear shorten the overall engine lifespan.

[0005] In summary, developing an erosion-resistant blade tenon is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide an erosion-resistant blade tenon. By optimizing the structural design of the engine fan blade tenon, the overall structural stability can be guaranteed, and the external pressure can be borne by the buffer area to improve the mechanical properties of the tenon. By spraying a high-performance double-layer composite coating on the entire surface of the tenon, while ensuring the overall surface strengthening of the tenon, the blade tenon has excellent wear resistance and shock absorption properties. By providing a groove on the side of the tenon and spraying a modified composite coating on the side surface (including the groove surface) and the hook angle side surface of the arc-shaped buffer area, the contact area between the tenon and the engine turntable can be effectively increased, further reducing the friction coefficient between the two, and the erosion resistance of the tenon itself can be improved.

[0007] To achieve the above object, the present invention provides an erosion-resistant blade tenon, specifically comprising:

[0008] The erosion-resistant blade tenon is in an I-shaped structure as a whole, and the top of the I-shaped structure is the tenon tail, which is in an inverted triangle shape;

[0009] The bottom of the I-shaped structure is a convex tenon, with arc-shaped protrusions at both ends of the tenon;

[0010] The center column of the I-shaped structure includes: an arc-shaped buffer area connected to the tail of the tenon, a lower arrow area composed of lines L1, L2, and L3, and a smooth transition area composed of line L3 and the convex tenon.

[0011] In a preferred embodiment, the erosion-resistant blade tenon is a bilaterally symmetrical structure.

[0012] In a preferred embodiment, the tail of the tenon has a 45° chamfer. More preferably, the bottom edge of the chamfer is a smooth straight line, so as to be tightly combined with the blade.

[0013] In a preferred embodiment, the horizontal distance from the outer vertex of the arc-shaped buffer area to the center vertical line is equal to the horizontal distance from the chamfer vertex to the center vertical line. The above design can effectively alleviate the pressure borne by the chamfer, and the arc-shaped buffer area is a semicircular buffer zone.

[0014] In a preferred embodiment, a plurality of grooves are provided on the side of the arc-shaped buffer area. Preferably, the grooves are arranged in a stepped manner, symmetrically distributed vertically with the outer vertex of the arc-shaped buffer area as the center; more preferably, five stepped grooves are provided on one side of the arc-shaped buffer area upward or downward in the horizontal direction, and a total of ten stepped grooves are provided on one side of the arc-shaped buffer area. The two outermost grooves of the arc-shaped buffer area are located at the vertical section position of the outer vertex of the arc-shaped buffer area.

[0015] In a preferred embodiment, a single stepped groove in the stepped groove is rectangular.

[0016] In a preferred embodiment, the length l of the stepped groove is 0.6-0.8 times the thickness of the side of the arc-shaped buffer area. Preferably, the length l of the groove is 0.65, 0.7, 0.75, or 0.8 times the thickness of the side of the arc-shaped buffer area.

[0017] In a preferred embodiment, the depth of the stepped groove is 0.1-0.5 times the length from the outer vertex of the arc-shaped buffer area to the center vertical line. Preferably, the groove depth is 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, or 0.45 times the length from the outer vertex of the arc-shaped buffer area to the center vertical line.

[0018] In a preferred embodiment, the height h of the stepped groove is 0.1-0.5 times the length from the outer vertex of the arc buffer area to the center vertical line. Preferably, the groove height h is 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, or 0.45 times the length from the outer vertex of the arc buffer area to the center vertical line; more preferably, the depth and height h of each stepped groove are the same; most preferably, the depth and height h of each groove are both 0.1 times the length from the outer vertex of the arc buffer area to the center vertical line.

[0019] In a preferred embodiment, the arc-shaped buffer area is a semicircular buffer area, and the stepped grooves are symmetrically distributed in the horizontal direction with the tangential radius of the semicircle center as the center.

[0020] In this invention, the purpose of providing a groove on the side of the arc-shaped buffer area of ​​the blade tenon is to increase the contact area between the entire buffer area and the engine turntable. Because the surface of the groove is coated with a PPS-PTFE-GO coating, which contains graphene components, the entire coating has a good lubrication effect, effectively reducing the friction coefficient of the groove surface. In addition, PPS and PTFE themselves have excellent erosion resistance.

[0021] In a preferred embodiment, the angle formed between the line L1 and the central vertical line is 10°-20°, the angle formed between the line L2 and the central vertical line is 45°-60°, and the angle formed between the line L3 and the central vertical line is 30°-45°, so that the intersection of the line L2 and the line L3 forms a hook angle;

[0022] Preferably, the angle formed between the line L1 and the central vertical line is 15°, the angle formed between the line L2 and the central vertical line is 45°, and the angle formed between the line L3 and the central vertical line is 30°;

[0023] More preferably, the hook angle formed by the intersection of the line L2 and the line L3 is 30°-60°.

[0024] In the present invention, by designing the inclination angles of the lines L1, L2 and L3, it is possible to ensure that the size of the barb will not be too long to cause brittle fracture, thereby improving the mechanical strength.

[0025] In a preferred embodiment, the horizontal distance between the intersection of the line L2 and the line L3 and the center vertical line is 0.5-1 times the horizontal distance between the vertex outside the arc buffer area and the center vertical line. Preferably, the horizontal distance between the intersection of the line L2 and the line L3 and the center vertical line is 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, or 0.95 times the horizontal distance between the vertex outside the arc buffer area and the center vertical line.

[0026] In a preferred embodiment, the smooth transition area is an arc. Preferably, the arc of the smooth transition area is completely consistent with the arc shape of the arc-shaped protrusion of the tenon. More preferably, the arcs of the smooth transition area and the arc-shaped protrusion of the tenon are both circular arcs.

[0027] In a preferred embodiment, the length of the highest point of the arc-shaped protrusions at both ends of the convex tenon from the bottom edge of the I-shaped structure is 0.5-1 times the length of the outer vertex of the arc-shaped buffer area from the center vertical line. Preferably, the length of the highest point of the arc-shaped protrusions at both ends of the convex tenon from the bottom edge of the I-shaped structure is 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, or 0.95 times the length of the outer vertex of the arc-shaped buffer area from the center vertical line.

[0028] In the present invention, the overall structure of the blade tenon is different from the traditional longitudinal tree-shaped blade tenon. There is an arc-shaped buffer zone in the middle of the tenon. The buffer zone can bear most of the residual stress and prevent the force from being concentrated below. The barbed structure below the buffer zone can effectively alleviate the centrifugal force generated by the high-speed rotation of the blade.

[0029] In a preferred embodiment, the entire surface of the tenon is covered with a PPS-PTFE double-layer composite coating.

[0030] In a preferred embodiment, the entire side surface of the arc-shaped buffer area, as well as the side surfaces of the line L2 and the line L3 are all covered with the PPS-PTFE-GO coating.

[0031] In a preferred embodiment, in the PPS-PTFE double-layer composite coating, the mass fraction of PPS in each layer of the coating is 35-45%, and the mass fraction of PTFE is 65-55%;

[0032] The PPS-PTFE double-layer composite coating comprises a buffer layer and a pressure-resistant layer from the inside to the outside along the attachment surface.

[0033] In a preferred embodiment, in the PPS-PTFE-GO coating, the mass fraction of PPS is 55-60%, the mass fraction of PTFE is 30-45%, and the mass fraction of graphene powder is 5-10%.

[0034] In a preferred embodiment, the erosion-resistant blade tenon has a mass loss of less than 8 mg under erosion test; and an erosion of less than 21 kg / m 2 ·s.

[0035] Another object of the present invention is to provide a method for preparing an erosion-resistant blade tenon, wherein two layers of PPS-PTFE composite coating are sprayed on the surface of the blade tenon, and a layer of PPS-PTFE-GO composite coating is sprayed on a specific area, thereby improving the impact resistance, hydrophobic and anti-icing effect, and lubrication ability of the blade tenon.

[0036] To achieve the above object, the present invention provides a method for preparing an erosion-resistant blade tenon, which specifically comprises the following steps:

[0037] S1 Material Preparation: Process the tenon into an erosion-resistant blade tenon structure and perform pretreatment, mix polytetrafluoroethylene and polyphenylene sulfide to prepare coating A, and mix polytetrafluoroethylene, polyphenylene sulfide and graphene oxide to prepare coating B;

[0038] S2 Preparation of PPS-PTFE buffer layer: spray coating A evenly on the pre-treated blade tenon surface, dry, and cool to room temperature;

[0039] S3: Preparation of PPS-PTFE pressure-resistant layer: coating A is evenly sprayed on the surface of the coating obtained in step S2, dried, cured, and cooled to room temperature;

[0040] S4 Preparation of PPS-PTFE-GO coating: On the surface of the coating obtained in step S3, coating B is evenly sprayed on the side surface of the arc buffer area and the side surfaces of lines L2 and L3, and dried, cured, and cooled to room temperature.

[0041] In a preferred embodiment, in step S1, the tenon structure can be processed using conventional methods known to those skilled in the art, as long as the corresponding structure can be produced. The present invention does not impose any particular limitations on this method. The blade tenon can be made of any conventional material known to those skilled in the art. In the embodiment of the present invention, the blade tenon is made of titanium alloy steel that meets aircraft service requirements.

[0042] In a preferred embodiment, in step S1, the purpose of the pretreatment is to improve the cleanliness and roughness of the blade tenon. Therefore, the specific treatment method is not limited, as long as the above-mentioned purpose can be achieved. The method adopted in the embodiment of the present invention is: first, the tenon is cleaned with an organic solvent to remove surface stains. Preferably, the organic solvent is acetone. Preferably, the cleaning method is ultrasonic cleaning. The specific cleaning power and time can be conventionally treated by those skilled in the art, as long as there is no stain remaining on the surface. The surface of the cleaned tenon is then sandblasted to increase the surface roughness and thereby improve the bonding strength between the coating and the substrate. For example, quartz sand is used for sandblasting, and the size of the quartz sand is 250-800 microns.

[0043] In a preferred embodiment, in step S1, the mass fraction of PPS in the coating A is 35-45%, and the mass fraction of PTFE is 65-55%, that is, the mass of PPS accounts for 35-45% of the total mass of PPS and PTFE, and the mass of PTFE accounts for 65-55% of the total mass of PPS and PTFE.

[0044] In a preferred embodiment, in step S1, in the coating B, the mass fraction of PPS is 55-60%, the mass fraction of PTFE is 30-45%, and the mass fraction of graphene powder is 5-10%.

[0045] In a preferred embodiment, in steps S2, S3 and S4, the spraying device and method can be any conventional device and method known to those skilled in the art. In the embodiment of the present invention, the mixed coating is loaded into an ANEST IWATA W-71 spray gun; the total air pressure regulating valve of the spray gun is adjusted to adjust the spray gun pressure to 0.3-0.6 MPa, the position of the muzzle and the workpiece is fixed, and the distance between the muzzle and the workpiece is maintained at 20 cm; the fan-shaped air pressure regulating valve is adjusted to maintain the spray angle at 45°-60°, and the flow regulating valve is adjusted to make the spray as fine as possible.

[0046] In a preferred embodiment, in step S2, the drying conditions can adopt conventional methods known to those skilled in the art, such as drying at a temperature of 100-120° C. for 5-15 minutes.

[0047] In a preferred embodiment, after the treatment in step S2, the thickness of the PPS-PTFE coating is 70-90 μm.

[0048] In a preferred embodiment, in step S3, the drying conditions can be conventional methods known to those skilled in the art, such as drying at a temperature of 100-120°C for 5-15 minutes. The curing device can be any device conventionally known to those skilled in the art, such as a box-type curing oven. The curing conditions are: heating to 350-450°C over 35-55 minutes, followed by constant temperature sintering for 15-25 minutes.

[0049] In a preferred embodiment, after the treatment in step S3, the thickness of the PPS-PTFE double-layer coating is 140-180 μm.

[0050] The PPS-PTFE double-layer composite coating described in the present invention is composed of a buffer layer and a pressure-resistant layer from the inside to the outside along the adhesion surface. The processing technology of the inner and outer film bases is basically the same. The only difference is that the pressure-resistant layer adds a curing step on the basis of the buffer layer processing technology to increase the coating strength.

[0051] In a preferred embodiment, the static water contact angle of the prepared PPS-PTFE double-layer composite coating can reach above 139°, and the membrane-base bonding strength thereof can also reach above 50N.

[0052] In a preferred embodiment, in step S4, the drying conditions can adopt conventional methods known to those skilled in the art, such as drying at a temperature of 100-120°C for 5-15 minutes; the curing operation is: heating to 350-450°C within 30-60 minutes, and then sintering at a constant temperature for 15-25 minutes.

[0053] In a preferred embodiment, after the treatment in step S4, the total thickness of the multilayer coating on the surface of the component covered with PPS-PTFE-GO is 150-200 μm.

[0054] Another object of the present invention is to provide applications of the aforementioned erosion-resistant blade tenon in aircraft applications. The blade tenon provided by the present invention exhibits excellent erosion resistance, wear resistance, hydrophobicity, anti-icing properties, and lubricity. Therefore, it can be used as a tenon for aircraft engine fan blades, positioned at the connection between the blade and the engine rotor, helping the blade withstand various service environments and extending the engine's service life.

[0055] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0056] 1. The chamfered bottom of the tail of the blade tenon of the present invention has the same size as the lateral size of the lower area, which ensures the stability of the overall structure while keeping the structure simple. When the tenon fails in the early stage, it can effectively transition to the buffer area below, which can temporarily ensure the normal operation of the blade and prevent it from breaking catastrophically.

[0057] 2. The curved buffer portion of the blade tenon of the present invention features stepped grooves on its sides, increasing the contact area between the groove's sides and the engine turntable. This allows the buffer portion to receive force over more areas, enhancing its buffering capacity and increasing the lifespan of the entire blade tenon. During operation, the blade's buffer portion experiences displacement under pressure. Therefore, the present invention incorporates a PPS-PTFE-GO composite coating on the groove surface. The graphene component in this coating enhances the coating's lubricity, slowing the overall failure rate of the blade tenon.

[0058] 3. The double-layer PPS-PTFE composite coating on the surface of the blade tenon is a double-layer structure with a buffer layer inside. It only needs to be dried at a temperature of 100℃-120℃ for 5-15 minutes to effectively protect the stepped grooves of the tenon buffer zone from wear. The external coating treatment process should be higher than the internal layer treatment process. It is then cured in a box-type curing furnace, heated to 350℃-450℃ within 35-55 minutes, and then sintered at a constant temperature for 15-25 minutes. The double-layer PPS-PTFE composite coating prepared in the embodiment of the present invention has a thickness of 160μm. SEM observation shows that the coating surface has a micro-nano secondary structure with a certain rough structure and a dense and compact cross-section structure. The unique surface structure gives it good hydrophobic and anti-icing properties, making it more lubricated and stable at the connection between the aircraft engine turntable and the blade tenon when the aircraft engine is in service. The coating has good erosion resistance when tested by an erosion tester. After being vertically hit by the erosion tester, only a small amount of flaky coating falls off, and the wear is very small. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] These and / or other aspects and advantages of the present invention will become more apparent and more readily understood from the following detailed description of embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0060] Figure 1 A front view of a blade tenon applied to an aircraft engine according to an embodiment of the present invention;

[0061] Figure 2 The present invention provides a partial cross-sectional view and a side view of a curved buffer area of ​​a blade tenon applied to an aircraft engine according to an embodiment of the present invention, wherein (a) is a partial cross-sectional view and (b) is a side view;

[0062] Figure 3 The surface micromorphology of the PPS-PTFE composite coating applied to the tenon surface of a blade of an aircraft engine according to one embodiment of the present invention;

[0063] Figure 4 The cross-sectional micromorphology of a PPS-PTFE composite coating applied to the tenon surface of a blade of an aircraft engine according to one embodiment of the present invention;

[0064] Figure 5 The erosion weight loss of the PPS-PTFE composite coating applied to the tenon surface of the blade of an aircraft engine according to one embodiment of the present invention;

[0065] Figure 6 The erosion rate of the PPS-PTFE composite coating applied to the surface of the blade tenon of an aircraft engine according to one embodiment of the present invention.

[0066] Description of main reference numerals:

[0067] 1-tenon tail, 11-chamfer, 12-chamfered bottom edge, 2-arc-shaped buffer area, 21-outer vertex of the arc-shaped buffer area, 3-line L1, 4-line L2, 5-line L3, 51-hook angle, 6-smooth transition area, 61-smooth transition area arc, 7-convex tenon, 71-convex tenon arc, 8 groove, 9PPS-PTFE-GO composite coating. DETAILED DESCRIPTION

[0068] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. However, it should be understood that the protection scope of the present invention is not limited to the specific embodiments.

[0069] The present invention provides a schematic diagram of an erosion-resistant blade tenon structure as shown in FIG. Figure 1 As shown in the figure, it can be seen that the erosion-resistant blade tenon is an I-shaped structure as a whole, the top of the I-shaped structure is the tenon tail (1), which is in the shape of an inverted triangle; the bottom of the I-shaped structure is the convex tenon (7), and the two ends of the tenon are arc-shaped protrusions; the column part of the I-shaped structure includes: an arc-shaped buffer area (2) connected to the tenon tail, a lower arrow area composed of lines L1 (3), lines L2 (4), and lines L3 (5), and a smooth transition area (6) composed of lines L3 (5) and the convex tenon (7).

[0070] In a preferred embodiment, the tail of the tenon has a chamfer (11), and the length of the chamfer bottom edge (12) from the center vertical line is consistent with the length of the outer vertex (21) of the arc-shaped buffer area from the center vertical line, that is, Figure 2 In (a), the x length is consistent with the z length, so that the bottom length of the chamfer is the same as the lateral length of the arc area below, which is conducive to structural stability.

[0071] In a preferred embodiment, a plurality of grooves (8) are provided on the side of the arc-shaped buffer region (2), which are symmetrically distributed vertically in the horizontal direction with the outer vertex (21) of the arc-shaped buffer region as the center.

[0072] In a preferred embodiment, the angle formed by line L1 (3) and the central vertical line is 10°-20°, the angle formed by line L2 (4) and the central vertical line is 40°-50°, and the angle formed by line L3 (5) and the central vertical line is 20°-40°, so that the intersection of line L2 (4) and line L3 (5) forms a hook angle (51). The horizontal distance between the intersection of line L2 (4) and line L3 (5) and the central vertical line is 0.5-1 times the horizontal distance between the vertex (21) outside the arc buffer area and the central vertical line, that is, Figure 2 In (a), w:x=(0.5-1):1.

[0073] In a preferred embodiment, the smooth transition area (6) is an arc, and the smooth transition area arc (61) is completely consistent with the shape of the convex tenon arc (71). Preferably, it can be regarded as first flipping the convex tenon arc (71) horizontally upward and then flipping it vertically to the left to obtain the smooth transition area arc (61).

[0074] In a preferred embodiment, the length of the highest point of the arc-shaped protrusions at both ends of the convex tenon (7) from the bottom edge of the I-shaped structure is 0.5-1 times the length of the vertex (21) outside the arc-shaped buffer area from the center vertical line, that is, Figure 2 In (a), y:x=(0.5-1):1.

[0075] Depend on Figure 2 It can be seen from the partial cross-sectional view (a) and side view (b) of the arc-shaped buffer area of ​​the tenon provided that, on the single side surface of the arc-shaped buffer area (2), five grooves (8) are opened upward or downward in the horizontal direction with the outer vertex (21) of the arc-shaped buffer area as the center, and the two outermost grooves (8) are located at the vertical section position of the outer vertex (21) of the arc-shaped buffer area; a total of ten grooves (8) are opened on the single side surface of the arc-shaped buffer area (2).

[0076] In a preferred embodiment, the length l of the groove is 0.6-0.8 times the thickness of the side of the arc-shaped buffer area, the depth of the groove is 0.1-0.5 times the length from the outer vertex of the arc-shaped buffer area to the center vertical line, and the height h of the groove is 0.1-0.5 times the length from the outer vertex of the arc-shaped buffer area to the center vertical line. More preferably, the depth and height h of each groove are 0.1 times the length from the outer vertex of the arc-shaped buffer area to the center vertical line.

[0077] In a preferred embodiment, the entire surface of the tenon is covered with a PPS-PTFE double-layer composite coating.

[0078] In a preferred embodiment, the side surface of the arc-shaped buffer area, the groove surface, and the side wall surface formed by the groove and the arc-shaped buffer area are covered with a PPS-PTFE-GO composite coating on the basis of being covered with a PPS-PTFE double-layer composite coating.

[0079] In a preferred embodiment, the side surfaces of line L2 and line L3 are covered with a PPS-PTFE double-layer composite coating and then completely covered with a PPS-PTFE-GO coating, that is, the upper and lower surfaces of the side of the hook angle (51) are completely covered with a PPS-PTFE-GO coating.

[0080] The technical solution of this application is described in detail below through specific embodiments:

[0081] Unless otherwise specified, the technical means used in the present invention are conventional means well known to those skilled in the art, and the various raw materials, reagents, instruments and equipment used in the present invention can be purchased on the market or can be prepared by existing methods. The reagents used in the present invention are analytically pure unless otherwise specified. In the present invention, the polytetrafluoroethylene used is PTFE emulsion (60wt.%), purchased from Shanghai San Ai Fu New Materials Co., Ltd. The polyphenylene sulfide used is a powder (300 mesh) purchased from Zhejiang Xinhecheng Special Materials Co., Ltd. The graphene oxide used is a powder (1100 mesh) purchased from Dazhan Nano (Guangdong) Co., Ltd. The normal temperature is 25°C ± 5°C.

[0082] Example 1:

[0083] (1) Processing of the overall tenon shape: The base material is processed using laser processing technology. The instrument uses a CNC machine tool and processes according to the set program language, starting from the tail of the blade tenon to the head of the blade tenon. The tail of the blade tenon is chamfered at 45° and connected to the arc-shaped buffer zone downwards. The length of the bottom edge of the chamfer from the center vertical line is consistent with the length of the outer vertex of the arc-shaped buffer area from the center vertical line; the lower part of the blade arc-shaped buffer area is processed with a straight line L1 area that forms an angle of 15° with the center vertical line, and the lower part has a straight line L2 area and a straight line L3 area that form angles of 45° and 30° with the center vertical line respectively; straight line L2 and straight line L3 form a hook angle, and the horizontal distance w from the intersection of line L2 and line L3 to the center vertical line is 0.5 times the horizontal distance x from the outer vertex of the arc-shaped buffer area to the center vertical line; then a smooth transition area and a convex tenon are processed downwards in an arc line from straight line L3, the arc line of the convex tenon has the same shape as the arc line of the smooth transition area, and the length y of the highest point of the convex tenon from the bottom edge of the tenon is 0.75 times the length x from the outer vertex of the arc-shaped buffer area to the center vertical line.

[0084] After the overall appearance is processed, the surface is polished using a milling machine, first rough milling and then fine milling, to keep the overall surface of the blade tenon smooth, which is conducive to the subsequent spray coating.

[0085] Groove Processing: CNC milling machines create stepped grooves on the side of the semicircular buffer zone of the blade tenon. Ten stepped grooves are located on each side, symmetrically distributed along the semicircular center of the arc-shaped buffer zone. Five grooves are created on each side, with the two outermost grooves located at the vertical section of the outer vertex of the arc-shaped buffer zone. Rough milling is performed first, followed by fine milling. The inner walls of the stepped grooves are then polished using a polishing machine.

[0086] Pretreatment of the blade tenon: ultrasonic cleaning is performed on the tenon surface to remove surface stains. The cleaning fluid used is acetone. The blade tenon surface is then sandblasted with quartz sand of 250-800μm in size.

[0087] (2) Preparation of coating A: PPS powder particles were added to the PTFE emulsion in a ratio of 35% by mass of PTFE and 65% by mass of PPS to obtain a PTFE / PPS coating.

[0088] (3) Preparation of PPS-PTFE buffer layer: Stir coating A with a magnetic stirrer for 45 minutes to fully mix the mixed coating, and then load the mixed coating into the ANEST IWATA W-71 spray gun. Adjust the total air pressure regulating valve of the spray gun to adjust the spray gun pressure to 0.6MPa, fix the position of the muzzle and the workpiece, and keep the distance between the muzzle and the workpiece at 20cm. Adjust the fan-shaped air pressure regulating valve to maintain the spray angle at 45°. Spray coating A evenly on the surface of the blade tenon obtained in step (1), dry it at 100℃ for 10 minutes, and cool it to room temperature.

[0089] (4) Preparation of PPS-PTFE pressure-resistant layer: Using the process parameters of step (3), evenly spray coating A on the surface of the blade tenon obtained in step (3), dry at 100°C for 10 minutes, heat to 450°C within 40 minutes, then sinter at a constant temperature for 25 minutes, and cool to room temperature.

[0090] (5) Preparation of coating B: PPS powder particles and graphene powder were added to the PTFE emulsion in a ratio of 35% by mass of PTFE, 55% by mass of PPS, and 10% by mass of graphene powder to obtain a PTFE / PPS / graphene coating.

[0091] (6) Preparation of PPS-PTFE-GO coating: Stir the prepared coating B with a magnetic stirrer for 55 minutes to fully mix the mixed coating, and then load the mixed coating into the ANEST IWATA W-71 spray gun. Adjust the total air pressure regulating valve of the spray gun, adjust the spray gun pressure to 0.6MPa, fix the position of the muzzle and the workpiece, and keep the distance between the muzzle and the workpiece at 20cm. Adjust the fan-shaped air pressure regulating valve to maintain the spray angle at 45°. Spray coating B evenly on the specific position of the surface of the blade tenon obtained in step (IV), dry it at 110°C and then cure it, then heat it to 400°C within 30 minutes, and then sinter it at a constant temperature for 25 minutes.

[0092] The specific positions refer to: the side surface of the arc-shaped buffer zone of the blade tenon, the surface of the stepped groove, the interior and side wall, and the side surface of the hook angle area formed by the line L2 and the line L3.

[0093] Performance testing:

[0094] (I) Coating micromorphology inspection: Before observing the surface morphology of the coating using a scanning electron microscope (SEM) (MERLIN Compact, ZEISS, Germany), the coating surface was first sprayed with gold, and then the micromorphology of the coating was observed and analyzed. The surface and cross-section of the coating were inspected respectively, and the inspection results are shown in the attached figure. Figure 3 and 4 As shown. Figure 3 The SEM image of the surface morphology of the PPS-PTFE composite coating at 200 microns is clearly shown. The rough structure of the coating surface gives the film good erosion resistance and hydrophobicity. Figure 4 The cross-sectional morphology of the PPS-PTFE composite coating can be seen. The spiral structure of PTFE gives the entire film extremely strong stability, and the addition of PPS makes it even more stable. The cross-sectional view in the figure shows a dense structure of the entire coating without large pores.

[0095] (II) Erosion resistance test of coating: ASTM G76 erosion test machine is used to simulate the erosion phenomenon caused by the impact of particle air jet on the surface. The erosion particles are replaced in each experiment to ensure the uniqueness of the experimental variables and eliminate the interference of other external factors. The erosion angle is set from 15-90°, increasing by 15°. The particle size of the erosion particles is 200 mesh, the erosion speed is 50m / s, and the erosion time is 10 minutes. The erosion test results are as follows: Figure 4 and Figure 5 As shown in the figure, the mass loss of erosion weight loss increases with the increase of erosion angle. When the erosion angle reaches 90°, the mass loss is 7.7 mg; the erosion rate also increases with the increase of erosion angle. When the erosion angle reaches 90°, the erosion rate is 20.3 kg / m 2 ·s.

[0096] Example 2:

[0097] (1) Processing of the overall tenon shape: The base material is processed using laser processing technology. The instrument uses a CNC machine tool and processes according to the set program language, starting from the tail of the blade tenon to the head of the blade tenon. The tail of the blade tenon is chamfered at 45° and connected to the arc-shaped buffer zone downwards. The length of the bottom edge of the chamfer from the center vertical line is consistent with the length of the outer vertex of the arc-shaped buffer area from the center vertical line; the lower part of the blade arc-shaped buffer area is processed with a straight line L1 area that forms an angle of 15° with the center vertical line, and the lower part has a straight line L2 area and a straight line L3 area that form angles of 50° and 35° with the center vertical line respectively; straight line L2 and straight line L3 form a hook angle, and the horizontal distance w from the intersection of line L2 and line L3 to the center vertical line is 0.5 times the horizontal distance x from the outer vertex of the arc-shaped buffer area to the center vertical line; then a smooth transition area and a convex tenon are processed downwards in an arc line from straight line L3, the arc line of the convex tenon has the same shape as the arc line of the smooth transition area, and the length y of the highest point of the convex tenon from the bottom edge of the tenon is 0.65 times the length x from the outer vertex of the arc-shaped buffer area to the center vertical line.

[0098] After the overall appearance is processed, the surface is polished using a milling machine, first rough milling and then fine milling, to keep the overall surface of the blade tenon smooth, which is conducive to the subsequent spray coating.

[0099] Groove Processing: CNC milling machines create stepped grooves on the side of the semicircular buffer zone of the blade tenon. Ten stepped grooves are located on each side, symmetrically distributed along the semicircular center of the arc-shaped buffer zone. Five grooves are created on each side, with the two outermost grooves located at the vertical section of the outer vertex of the arc-shaped buffer zone. Rough milling is performed first, followed by fine milling. The inner walls of the stepped grooves are then polished using a polishing machine.

[0100] The pretreatment process for the blade tenon is as follows: the tenon surface is ultrasonically cleaned with acetone to remove surface stains. The blade tenon surface is then sandblasted with quartz sand of 250-800μm in size.

[0101] (2) Preparation of coating A: PPS powder particles were added to the PTFE emulsion in a ratio of 40% by mass of PTFE and 60% by mass of PPS to obtain a PTFE / PPS coating.

[0102] (3) Preparation of PPS-PTFE buffer layer: Stir coating A with a magnetic stirrer for 50 minutes to fully mix the mixed coating, and then load the mixed coating into the ANEST IWATA W-71 spray gun. Adjust the total air pressure regulating valve of the spray gun to adjust the spray gun pressure to 0.6MPa, fix the position of the muzzle and the workpiece, and keep the distance between the muzzle and the workpiece at 20cm. Adjust the fan-shaped air pressure regulating valve to maintain the spray angle at 45°. Spray coating A evenly on the surface of the blade tenon obtained in step (1), dry it at 110℃ for 10 minutes, and cool it to room temperature.

[0103] (4) Preparation of PPS-PTFE pressure-resistant layer: Using the process parameters of step (3), evenly spray coating A on the surface of the blade tenon obtained in step (3), dry at 100°C for 10 minutes, heat to 400°C within 40 minutes, then sinter at a constant temperature for 30 minutes, and cool to room temperature.

[0104] (5) Preparation of coating B: PPS powder particles and graphene powder were added to the PTFE emulsion in a ratio of 30% by mass of PTFE, 60% by mass of PPS, and 10% by mass of graphene powder to obtain a PTFE / PPS / graphene coating.

[0105] (6) Preparation of PPS-PTFE-GO coating: Stir the prepared coating B with a magnetic stirrer for 55 minutes to fully mix the mixed coating, and then load the mixed coating into the ANEST IWATA W-71 spray gun. Adjust the total air pressure regulating valve of the spray gun, adjust the spray gun pressure to 0.6MPa, fix the position of the muzzle and the workpiece, and keep the distance between the muzzle and the workpiece at 20cm. Adjust the fan-shaped air pressure regulating valve to maintain the spray angle at 45°. Spray coating B evenly on the specific position of the surface of the blade tenon obtained in step (IV), dry it at 110°C and then cure it, then heat it to 400°C within 30 minutes, and then sinter it at a constant temperature for 25 minutes.

[0106] The specific positions refer to: the side surface of the arc-shaped buffer zone of the blade tenon, the surface of the stepped groove, the interior and side wall, and the side surface of the hook angle area formed by the line L2 and the line L3.

[0107] Erosion resistance test of coating: ASTM G76 erosion test machine is used to simulate the erosion phenomenon caused by the impact of particle air jet on the surface. The erosion particles will be replaced in each experiment to ensure the uniqueness of the experimental variables and eliminate the interference of other external factors. The set erosion angle varies from 15-90°, increasing by 15°. The particle size of the erosion particles is 200 mesh, the erosion speed is 50m / s, and the erosion time is 10 minutes. The results of the erosion experiment show that the mass loss of erosion weight loss increases with the increase of the erosion angle. When the erosion angle reaches 90°, the mass loss is 7.9mg; the erosion rate also increases with the increase of the erosion angle. When the erosion angle reaches 90°, the erosion rate is 19.8kg / m 2 ·s.

[0108] Example 3:

[0109] (1) Processing of the overall tenon shape: The base material is processed using laser processing technology. The instrument uses a CNC machine tool and processes according to the set program language, starting from the tail of the blade tenon to the head of the blade tenon. The tail of the blade tenon is chamfered at 45° and connected to the arc-shaped buffer zone downwards. The length of the bottom edge of the chamfer from the center vertical line is consistent with the length of the outer vertex of the arc-shaped buffer area from the center vertical line; the lower part of the blade arc-shaped buffer area is processed with a straight line L1 area that forms an angle of 15° with the center vertical line, and the lower part has a straight line L2 area and a straight line L3 area that form angles of 60° and 45° with the center vertical line respectively; straight line L2 and straight line L3 form a hook angle, and the horizontal distance w from the intersection of line L2 and line L3 to the center vertical line is 0.5 times the horizontal distance x from the outer vertex of the arc-shaped buffer area to the center vertical line; then a smooth transition area and a convex tenon are processed downwards in an arc line from straight line L3, the arc line of the convex tenon has the same shape as the arc line of the smooth transition area, and the length y of the highest point of the convex tenon from the bottom edge of the tenon is 0.5 times the length x from the outer vertex of the arc-shaped buffer area to the center vertical line.

[0110] After the overall appearance is processed, the surface is polished using a milling machine, first rough milling and then fine milling, to keep the overall surface of the blade tenon smooth, which is conducive to the subsequent spray coating.

[0111] Groove Processing: CNC milling machines create stepped grooves on the side of the semicircular buffer zone of the blade tenon. Ten stepped grooves are located on each side, symmetrically distributed along the semicircular center of the arc-shaped buffer zone. Five grooves are created on each side, with the two outermost grooves located at the vertical section of the outer vertex of the arc-shaped buffer zone. Rough milling is performed first, followed by fine milling. The inner walls of the stepped grooves are then polished using a polishing machine.

[0112] The pretreatment process for the blade tenon is as follows: the tenon surface is ultrasonically cleaned with acetone to remove surface stains. The blade tenon surface is then sandblasted with quartz sand of 250-800μm in size.

[0113] (2) Preparation of coating A: PPS powder particles were added to the PTFE emulsion in a ratio of 35% by mass of PTFE and 65% by mass of PPS to obtain a PTFE / PPS coating.

[0114] (3) Preparation of PPS-PTFE buffer layer: Stir coating A with a magnetic stirrer for 55 minutes to fully mix the mixed coating, and then load the mixed coating into the ANEST IWATA W-71 spray gun. Adjust the total air pressure regulating valve of the spray gun, adjust the spray gun pressure to 0.6MPa, fix the position of the muzzle and the workpiece, and keep the distance between the muzzle and the workpiece at 20cm. Adjust the fan-shaped air pressure regulating valve to maintain the spray angle at 45°. Spray coating A evenly on the surface of the blade tenon obtained in step (1), dry it at 120℃ for 10 minutes, and cool it to room temperature.

[0115] (4) Preparation of PPS-PTFE pressure-resistant layer: Using the process parameters of step (3), spray coating A evenly on the surface of the blade tenon obtained in step (3), dry at 120°C for 10 minutes, heat to 450°C within 40 minutes, then sinter at a constant temperature for 30 minutes and cool to room temperature.

[0116] (5) Preparation of coating B: PPS powder particles and graphene powder were added to the PTFE emulsion in a ratio of 35% by mass of PTFE, 60% by mass of PPS, and 5% by mass of graphene powder to obtain a PTFE / PPS / graphene coating.

[0117] (6) Preparation of PPS-PTFE-GO coating: Stir the prepared coating B with a magnetic stirrer for 55 minutes to fully mix the mixed coating, and then load the mixed coating into the ANEST IWATA W-71 spray gun. Adjust the total air pressure regulating valve of the spray gun, adjust the spray gun pressure to 0.6MPa, fix the position of the muzzle and the workpiece, and keep the distance between the muzzle and the workpiece at 20cm. Adjust the fan-shaped air pressure regulating valve to maintain the spray angle at 45°. Spray coating B evenly on the specific position of the surface of the blade tenon obtained in step (IV), dry it at 110°C and then cure it, then heat it to 400°C within 30 minutes, and then sinter it at a constant temperature for 30 minutes.

[0118] The specific positions refer to: the side surface of the arc-shaped buffer zone of the blade tenon, the surface of the stepped groove, the interior and side wall, and the side surface of the hook angle area formed by the line L2 and the line L3.

[0119] Erosion resistance test of coating: ASTM G76 erosion test machine is used to simulate the erosion phenomenon caused by the impact of particle air jet on the surface. The erosion particles are replaced in each experiment to ensure the uniqueness of the experimental variables and eliminate the interference of other external factors. The erosion angle is set from 15-90°, increasing by 15°. The particle size of the erosion particles is 200 mesh, the erosion speed is 50m / s, and the erosion time is 10 minutes. The erosion experiment can finally obtain the erosion weight loss and the erosion rate curve of the coating as shown in the attached figure. Figure 4 As shown in Figure 5, the mass loss of erosion weight increases with the increase of erosion angle. When the erosion angle reaches 90°, the mass loss is 7.8 mg. The erosion rate also increases with the increase of erosion angle. When the erosion angle reaches 90°, the erosion rate is only 20.2 kg / m 2 ·s.

[0120] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. An erosion-resistant blade tenon, characterized in that: The erosion-resistant blade tenon is in an I-shaped structure as a whole, and the top of the I-shaped structure is the tenon tail, which is in an inverted triangle shape; The bottom of the I-shaped structure is a convex tenon, with arc-shaped protrusions at both ends of the tenon; The I-shaped center column includes: an arc-shaped buffer area connected to the tail of the tenon, a downward arrow area formed by lines L1, L2, and L3, and a smooth transition area formed by line L3 and the convex tenon; A plurality of grooves are provided on the side surface of the arc-shaped buffer area, which are symmetrically distributed vertically along the horizontal direction with the outer vertex of the arc-shaped buffer area as the center.

2. The erosion-resistant blade tenon according to claim 1, characterized in that: The tail of the tenon has a 45° chamfer.

3. The erosion-resistant blade tenon according to claim 1, characterized in that: The angle formed between the line L1 and the central vertical line is 10°-20°, the angle formed between the line L2 and the central vertical line is 45°-60°, and the angle formed between the line L3 and the central vertical line is 30°-45°, so that the intersection of the line L2 and the line L3 forms a hook angle.

4. The erosion-resistant blade tenon according to claim 1, characterized in that: The entire surface of the tenon is covered with a PPS-PTFE double-layer composite coating.

5. The erosion-resistant blade tenon according to claim 4, characterized in that: The side surfaces of the arc-shaped buffer area and the side surfaces of the lines L2 and L3 are all covered with the PPS-PTFE-GO coating.

6. The erosion-resistant blade tenon according to claim 4, characterized in that: In the PPS-PTFE double-layer composite coating, the mass fraction of PPS in each layer of the coating is 35-45%, and the mass fraction of PTFE is 65-55%; The PPS-PTFE double-layer composite coating comprises a buffer layer and a pressure-resistant layer from the inside to the outside along the attachment surface.

7. The erosion-resistant blade tenon according to claim 1, characterized in that: The erosion-resistant blade tenon has a mass loss of less than 8 mg under erosion test and erosion of less than 21 kg / m 2 ·s.

8. The method for preparing the erosion-resistant blade tenon according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1 Material Preparation: Process the tenon into an erosion-resistant blade tenon structure and perform pretreatment, mix polytetrafluoroethylene and polyphenylene sulfide to prepare coating A, and mix polytetrafluoroethylene, polyphenylene sulfide and graphene oxide to prepare coating B; S2 Preparation of PPS-PTFE buffer layer: spray coating A evenly on the pre-treated blade tenon surface, dry, and cool to room temperature; S3: Preparation of PPS-PTFE pressure-resistant layer: coating A is evenly sprayed on the surface of the coating obtained in step S2, dried, cured, and cooled to room temperature; S4 Preparation of PPS-PTFE-GO coating: On the surface of the coating obtained in step S3, coating B is evenly sprayed on the side surface of the arc buffer area and the side surfaces of lines L2 and L3, and dried, cured, and cooled to room temperature.

9. Application of the erosion-resistant blade tenon according to any one of claims 1 to 7 in the field of aircraft.

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