Forming and manufacturing method of aircraft engine stator blade

Abstract

The invention relates to the technical field of aviation aircraft engine part manufacturing, in particular to an aircraft engine stator blade forming manufacturing method which comprises the following steps of S1, pretreatment, S2, upsetting treatment, S3, primary defect treatment, S4, die forging treatment, S5, secondary defect treatment and S6, solid solution aging treatment. After the upsetting and die forging forming method is adopted, the mold filling property of the blade becomes good, the structure is uniform, and the production efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of manufacturing aircraft engine parts, and in particular to a forming and manufacturing method for aircraft engine stator blades. Background Art

[0002] Aircraft engines are composed of three major components: compressor, combustion and turbine, as well as fuel system, lubricating oil system, air system, electrical system, intake and exhaust side system and bearing transmission system. Among the three major components, except for the combustion, the compressor and turbine are composed of rotor and stator. The stator is composed of inner and outer casings and guide (rectifier) ​​blades. The rotor is composed of blade disk, shaft and bearing, among which the blades are the most numerous. The blade is a special part with large number, complex shape, high requirements, high processing difficulty and frequent failure. It has always been the key to the production of various engine factories. Therefore, the human, material and financial resources invested in it are relatively large. In addition, domestic and foreign engine manufacturers are also making every effort to improve the performance of blades.

[0003] GH2132 alloy is an aging-hardened iron-based austenitic high-temperature alloy, similar to the US grade A286. It is suitable for replacing expensive nickel-based alloys in high-temperature environments of 650°C. It is widely used in high-temperature load-bearing parts of aircraft engines, such as turbine disks, blades and fasteners. During the thermal deformation process of GH2132 material, if the process parameters are not properly selected, there will be uneven structure, stress concentration, and defects such as early fatigue fracture. At the same time, during the thermal deformation process, the dynamic recrystallization inside the alloy can eliminate the defective structure caused by deformation and reduce the average grain size, which also largely determines the final microstructure and mechanical properties of the blade. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a forming and manufacturing method for aircraft engine stator blades.

[0005] A forming and manufacturing method for a stator blade of an aircraft engine comprises the following steps:

[0006] S1. Preheating

[0007] First, the two ends of the bar material with the specification of Φ50±0.7×430±1mm are measured to the size of 428±1mm, and chamfered to C3~C5, and turned to the end surface roughness ≤Ra3.2, and then loaded into the furnace at 1070~1090℃, and heat-insulated for 40~80min before being taken out of the furnace to obtain the blank;

[0008] S2. Upsetting treatment

[0009] Under the condition of the final forging temperature of 950-1050°C, the blank is subjected to three upset forging treatments respectively, and air-cooled to room temperature after each upset forging treatment. After the first air cooling to room temperature, the forging is placed in a mold for step I forming, after the second air cooling to room temperature, the forging is placed in a mold for step II forming and step III forming, and after the third air cooling to room temperature, the forging is placed in a mold for step IV forming and step V forming to obtain a pre-forged part;

[0010] S3, Level 1 defect handling

[0011] Shot blasting is used to remove dirt on the surface of the preforgings, and then grinding is performed to eliminate defects on the surface of the preforgings. The surface of the preforgings is shot blasted again, and then the preforgings are placed in an electric furnace at a temperature of 150 to 180°C for 30 to 40 minutes, and then taken out and sprayed with glass lubricant;

[0012] S4, die forging

[0013] Under the condition of final forging temperature of 950-1050℃, the forging is subjected to two-time die forging treatment, and one shot blasting, grinding, two-time shot blasting and lubrication treatment are carried out in sequence between the two-time die forging treatment, and the impact energy of the two-time die forging treatment is 30±10% and 45±10% of the total impact energy of the equipment respectively; heating treatment is carried out before each die forging, air cooling to room temperature is carried out after the first die forging treatment, and hot trimming is carried out after the second die forging treatment or air cooling is carried out on a tray first, and then cold heating trimming is carried out, and the target forging is obtained after trimming;

[0014] S5. Secondary defect handling

[0015] Shot blasting removes dirt from the surface of the target forging, then polishes to eliminate defects on the surface of the target forging, and shot blasts again to clean the surface of the target forging;

[0016] S6, solution aging treatment

[0017] The furnace is charged at 800-900℃, and then kept at 900℃ for 100-120min, taken out of the furnace and oil-cooled to room temperature, then charged at room temperature and kept at 700-710℃ for 950-970min, taken out of the furnace and dispersedly air-cooled to below 40℃, charged again at room temperature and kept at 640-660℃ for 950-970min, taken out of the furnace and air-cooled to below 40℃, and shot blasted to obtain aircraft engine stator blades.

[0018] Furthermore, in step S2, a heating treatment is performed before each upset treatment.

[0019] The methods of the first upset forging treatment and the second upset forging treatment are: heating the forging to 1070-1090°C, keeping it warm for 40-80 minutes and then taking it out of the furnace;

[0020] The method of the third upset forging treatment is: heating the forging to 1070-1090°C, holding the forging for 53-106 minutes, and then taking it out of the furnace. When the holding time is 80 minutes and after the holding time is over, the material is cleaned up respectively.

[0021] Note: During the third upset forging, the effective thickness of the blank increases after the first two upset forgings. In order to ensure sufficient heat preservation at the forming position and reduce the material deformation resistance to facilitate upset forging, the insulation time of the third upset forging is longer than the first two times.

[0022] When the blank exceeds the maximum holding time, it should be removed from the heating furnace to prevent the grains from growing further. After being removed and placed on a tray to cool to room temperature, it is transferred to the shot blasting equipment to remove the surface oxide scale to prevent affecting subsequent production.

[0023] Furthermore, in step S2, the mold is pre-treated, and the pre-treatment method is: using compressed air to blow away the dirt in the mold cavity, and spraying graphite inside the mold cavity.

[0024] Note: Use compressed air to blow away the dirt in the cavity, and use a spray gun to blow the graphite evenly to prevent graphite accumulation in the cavity and prevent residual graphite in the pits of the cavity.

[0025] Furthermore, the graphite spraying method is electrostatic spraying; the electrostatic spray gun of the electrostatic spraying is the cathode, the metal film-forming substrate is the anode and grounded, the electrostatic voltage is 1-100 kV, the electrostatic current is 1-100 μA, the output pressure is 0.05-0.1 MPa, the flow rate is controlled at 50-450 mL / min, the spray distance is 50-350 mm, the mist width is 50-450 mm, and the spraying time is 1-60 s;

[0026] Description: Electrostatic spraying can make graphite more evenly distributed on the surface of the workpiece, forming a more uniform, smooth and dense coating, with less paint mist splashing and less pollution to the environment.

[0027] Further, in step S3, the glass lubricant is GDS-17-1; the spraying method of the glass lubricant is electrostatic spraying; the electrostatic spray gun of the electrostatic spraying is the cathode, the metal film-forming substrate is the anode and grounded, the electrostatic voltage is 3 to 50 kV, the electrostatic current is 20 to 40 μA, the output pressure is 0.5 to 0.8 MPa, the flow rate is controlled at 200 to 300 mL / min, the spray distance is 150 to 200 mm, the mist width is 220 to 300 mm, and the spraying time is 1 to 5 min;

[0028] Note: The lubricant must be stirred evenly before use; the operation time from the beginning to the end of the blank spraying should not exceed 5 minutes, and no omissions should be allowed. After coating, no collision should be allowed to avoid falling off; turn over immediately after the first spraying, spray the bottom surface, and wait for the glass coating to dry before flowing to the next process. At high temperatures, the glass lubricant transforms from a solid state to a semi-fluid or fluid state, forming a continuous, dense, ductile, and compressive film layer on the contact surface between the blank and the mold, which plays a lubricating role. At the same time, the molten coating isolates harmful gases in the air during the entire thermal processing process, plays an anti-oxidation role, and also prevents surface defects caused by the oxide scale being brought into the extrusion deformation zone. The thermal conductivity of GDS-17-1 is small. When it melts at high temperature, GDS-17-1 surrounds the surface of the blank to form a dense film layer in a molten state. The blank is not in direct contact with the mold, which reduces the temperature drop on the surface of the blank and the temperature rise of the tooling, plays an insulating role, improves the plasticity of the metal and increases the service life of the tooling; the conductive base layer formed by graphite spraying ensures the uniform distribution of the glass lubricant, making the blade surface smooth and uniform without defects. The evenly distributed glass lubricant effectively reduces the resistance to metal flow and improves the fluidity of the molten metal during the high temperature and high pressure die forging process, so that the molten metal can fill the mold cavity faster and more completely, thereby obtaining blades with complex shapes.

[0029] Further, in step S4, the heating temperature of the first die forging process is 1070-1090° C., and the holding time is 75-150 min; the heating temperature of the second die forging process is 1070-1090° C., and the holding time is 75-150 min;

[0030] Description: The raw material of the stator blade in the present invention is GH2132 alloy, and in the range of 1070-1090°C, the plasticity of GH2132 metal is good, and it is easy to flow and fill complex-shaped molds, thereby improving the filling property of the blade; by maintaining a certain period of time at 1070-1090°C, it can be ensured that the internal structure of the material is fully recrystallized and homogenized, reducing micro defects in the forging process and improving the internal quality of the blade.

[0031] Further, in step S4, the parameters of the cold heating trimming are: heating temperature 850°C ± 10°C, holding time 15 to 30 minutes; after the trimming process, the blade is positioned in the trimming die, and dirt on the blade surface is cleaned, and then the forging misalignment is checked to be ≤1.0mm, and the residual burrs are: the residual burrs on one side of the blade body are ≤2.0mm, and the residual burrs at other positions are ≤1.5mm; and the existing defects are repaired in time to ensure that the forgings are defect-free after trimming;

[0032] Note: By heating and keeping warm at 850±10℃ for 15-30min, the material can maintain a certain plasticity, which helps to reduce the generation of cracks during the trimming process, thereby improving the filling property of the blade. During the trimming process, by controlling the heating temperature and the holding time, it can be ensured that the structure of the material does not change unevenly during the trimming process, thereby ensuring the uniformity of the blade's structure. Compared with cold trimming, cold heating trimming can reduce shear stress because it is carried out in a hot state, thereby reducing the generation of microcracks during cold cutting.

[0033] Further, the target forging surface after the step S5 is processed is subjected to a weld thinning and homogenizing treatment, wherein the weld thinning and homogenizing treatment method is as follows: the weld of the target forging is hammered with a small arc-shaped hammer with a radius of 8 to 10 mm, the hammering force is 2 to 3 N, the hammering rate is 100 to 140 times / min, and the hammering time is 20 to 30 s, so that the metal at the weld of the target forging is thinned and extended to the surroundings, and then a layer of thermal insulation coating with a thickness of 0.1 to 0.5 μm is sprayed on the weld thinning of the target forging, and an auxiliary frequency of 80 to 100 Hz and a current density of 5 to 20 A / cm 3 The alternating current is adjusted for 5 to 8 minutes.

[0034] Description: Weld thinning and homogenization treatment can improve the material's microstructure by offsetting some weld shrinkage and reducing welding stress, reducing the thickness of the weld area, and thus improving the material's mechanical properties. Fine grain structure is usually accompanied by better strength because grain boundaries can effectively hinder the movement of dislocations. In addition, weld thinning and homogenization treatment helps to eliminate or reduce stress concentration generated during welding, which is crucial to improving the fatigue life and crack resistance of the material, and indirectly improves the tensile strength of the material. Thermal insulation coatings can effectively reduce heat loss and improve heating efficiency, which is particularly important for welding and subsequent heat treatment processes because it helps maintain a suitable temperature in the weld area, thereby ensuring welding quality. Secondly, thermal insulation coatings usually have good thermal shock stability and can resist material expansion and contraction caused by temperature changes, which can reduce the risk of weld damage or cracks caused by temperature fluctuations.

[0035] Furthermore, the thermal insulation coating comprises, by mass percentage, 5-10% of boron nitride powder, 10-20% of talc, 10-15% of silica aerogel, 3-10% of aluminum silicate, 1-3% of glass microspheres and the balance of waterborne epoxy resin;

[0036] Description: The addition of hydrophobic fumed silica can improve the adhesion and tensile strength of the coating, while the pore volume of aerogel helps to reduce the thermal conductivity of the coating and avoid cracks and peeling. Aluminum silicate can improve the thermal conductivity and high temperature resistance of the coating. Boron nitride powder has the excellent property of low thermal expansion coefficient. Talc has good thermal stability. Water-based epoxy resin can promote the bonding between the thermal insulation coating and the thinning of the weld. The spherical structure of the glass microspheres reduces the friction resistance inside the coating, enhances the fluidity of the coating, makes it easier to penetrate into areas with complex shapes, and improves the filling effect.

[0037] Furthermore, the thermal insulation coating is sprayed by supersonic flame thermal coating, and the process parameters of the supersonic flame thermal spraying are: the distance between the spray gun and the workpiece is 200-220 mm, the spraying angle is 40-60°, and the flow rate is controlled at 50-450 mL / min;

[0038] Description: The high-speed particle impact produced by supersonic spraying can achieve mechanical interlocking between the coating and the substrate and improve the bonding strength of the coating. This is especially important for weld thinning areas because these areas may have stress concentration and require stronger coating adhesion. In the manufacture of high-temperature components such as aircraft engine blades, supersonic flame spraying can significantly improve the wear resistance and corrosion resistance of the material and extend the service life of the components.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) After the forming method of top forging + die forging used in the present invention, the forging temperature and pressure are precisely controlled to ensure that the metal flows smoothly in the die, thereby improving the filling property of the blade. Top forging first performs preliminary forming on the material to provide a suitable blank shape for subsequent die forging, and die forging further refines and improves the shape of the blade to ensure that the metal can evenly fill the complex geometric shape of the die. During the die forging process, the metal undergoes recrystallization and grain refinement, which helps to obtain a more uniform microstructure. The combined use of top forging and die forging can better control the deformation of the material and reduce the formation of internal defects such as cracks and holes, thereby achieving uniformity of organization; the die forging process can more accurately control the use of materials, thereby reducing material waste. Since the forging is close to the final shape, the loss of material in subsequent processing steps such as cutting and grinding is reduced. Since the top forging process uses a die, the deformation of the metal is carried out in the die cavity, and the desired shape can be obtained more quickly. The filling property of the blade is improved, the organization is uniform, and high automation and continuous production can be achieved, which significantly improves production efficiency, is suitable for mass production, and has high production efficiency.

[0041] (2) The present invention can improve the microstructure of the material by offsetting some weld shrinkage and reducing welding stress, thereby reducing the thickness of the weld area through weld thinning and homogenization treatment, thereby improving the mechanical properties of the material. At the same time, it helps to eliminate or reduce the stress concentration generated during the welding process, thereby improving the fatigue life and crack resistance of the material, and indirectly improving the tensile strength of the material. The thermal insulation coating can effectively reduce heat loss and improve heating efficiency, which is particularly important for welding and subsequent heat treatment processes because it helps to maintain a suitable temperature in the weld area, thereby ensuring welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a three-dimensional schematic diagram of the upset die of the present invention;

[0043] Figure 2 It is a schematic diagram of the forming process of step I of the present invention;

[0044] Figure 3 It is a schematic diagram of forming in step II of the present invention;

[0045] Figure 4 It is a schematic diagram of the forming process of step III of the present invention;

[0046] Figure 5 It is a schematic diagram of the forming process of step IV of the present invention;

[0047] Figure 6 It is a schematic diagram of the forming process of step V of the present invention. DETAILED DESCRIPTION

[0048] In order to further illustrate the method adopted by the present invention and the effect achieved, the technical solution of the present invention will be clearly and completely described in combination with experiments below.

[0049] Embodiment 1: A forming and manufacturing method for a stator blade of an aircraft engine, comprising the following steps:

[0050] S1. Preprocessing

[0051] First, the two ends of the bar with a specification of Φ50×430mm are measured to a size of 428mm, and chamfered to C4, and the end surface is turned to a roughness of Ra3.2, and then loaded into a furnace at 1080℃, and heat-treated for 60 minutes before being taken out of the furnace to obtain a blank;

[0052] S2. Upsetting treatment

[0053] Under the condition of a final forging temperature of 1000°C, the blank is subjected to three upset forging treatments respectively, and air-cooled to 27°C after each upset forging treatment. After the first air cooling to room temperature, the forging is placed in a mold for step I forming, and after the second air cooling to room temperature, the forging is placed in a mold for step II forming and step III forming. After the third air cooling to room temperature, the forging is placed in a mold for step IV forming and step V forming to obtain a pre-forged part; wherein, step I forming corresponds to the first upset forging treatment, step II and step III forming correspond to the second upset forging treatment, and step IV and step V forming correspond to the third upset forging treatment; Figure 1 From top to bottom in the figure, there are molds corresponding to step I forming, step II forming, step III forming, step IV forming and step V forming;

[0054] S3, Level 1 defect handling

[0055] The dirt on the surface of the pre-forged parts is removed by shot blasting at a speed of 75 m / s and a shot blasting time of 15 min, and then the surface defects of the pre-forged parts are eliminated by grinding. The surface of the pre-forged parts is cleaned by shot blasting again at a speed of 75 m / s and a shot blasting time of 35 min. The pre-forged parts are then placed in an electric furnace at a furnace temperature of 160°C for 35 min, and then sprayed with glass lubricant after being taken out. Among them, the grinding defects shall not exceed 2 / 3 of the machining allowance, and the grinding width shall be 6 times the grinding depth;

[0056] S4, die forging

[0057] Under the condition of final forging temperature of 1000℃, the forgings are subjected to two-time die forging treatment. Between the two-time die forging treatments, shot blasting and grinding are carried out at a shot blasting speed of 75m / s and a shot blasting time of 15min. Secondary shot blasting and glass lubricant are sprayed at a shot blasting speed of 75m / s and a shot blasting time of 35min. Then the pre-forged pieces are placed in the mold cavity for die forging. The impact energy of the two-time die forging treatments is 30% and 45% of the total impact energy of the equipment respectively. Before each die forging treatment, heating treatment is carried out. After the first die forging treatment, air cooling is carried out to 27℃. After the second die forging treatment, the edges are trimmed while hot. After trimming, air cooling is carried out to obtain the target forgings. Among them, the grinding defect shall not exceed 2 / 3 of the machining allowance, and the grinding width shall be 6 times of the grinding depth.

[0058] S5. Secondary defect handling

[0059] The dirt on the surface of the target forging is removed by shot blasting at a speed of 75 m / s and a shot blasting time of 15 min, and then the surface defects of the target forging are eliminated by grinding. The surface of the target forging is cleaned by shot blasting again at a speed of 75 m / s and a shot blasting time of 35 min. The grinding defects shall not exceed 2 / 3 of the machining allowance, and the grinding width shall be 6 times the grinding depth;

[0060] S6, solution aging treatment

[0061] The furnace is loaded at 850℃, and then kept at 900℃ for 110min, and then cooled to 27℃ by oil after being taken out of the furnace, and then loaded at 27℃ and kept at 705℃ for 960min, and then air-cooled to below 40℃ after being taken out of the furnace, and then loaded again at 27℃ and kept at 650℃ for 960min, and then air-cooled to 40℃ after being taken out of the furnace, and the aircraft engine stator blades are obtained after shot blasting;

[0062] In step S2, a heating treatment is performed before each upset forging treatment. The methods of the first upset forging treatment and the second upset forging treatment are: heating the forging to 1080° C., keeping the temperature for 60 minutes and then taking it out of the furnace;

[0063] The method of the third upset forging treatment is: heating the forging to 1080°C, keeping it in heat for 75 minutes, taking it out of the furnace, and cleaning the material after the end of the heat preservation treatment time;

[0064] In step S2, the mold is pre-treated, and the pre-treatment method is: blow the dirt in the mold cavity clean with compressed air, and spray graphite inside the mold cavity; the graphite spraying method is electrostatic spraying, during electrostatic spraying, the electrostatic spray gun is the negative electrode, the metal film-forming substrate at the weld is the positive electrode and grounded, the electrostatic voltage is 50kV, the electrostatic current is 50μA, the output pressure is 0.08MPa, the flow rate is controlled at 280mL / min, the spray distance is 200mm, the mist width is 250mm, and the spraying time is 30s;

[0065] In step S3, the glass lubricant is GDS-17-1; the spraying method of the glass lubricant is electrostatic spraying; the electrostatic spray gun of the electrostatic spraying is the cathode, the metal film-forming substrate is the anode and grounded, the electrostatic voltage is 25 kV, the electrostatic current is 30 μA, the output pressure is 0.65 MPa, the flow rate is controlled at 250 mL / min, the spray distance is 175 mm, the mist width is 270 mm, and the spraying time is 3 min;

[0066] In step S4, the heating temperature of the first die forging process is 1080° C., and the holding time is 100 min; the heating temperature of the second die forging process is 1080° C., and the holding time is 120 min;

[0067] In step S4, the parameters of cold heating trimming are: heating temperature 850°C, holding time 22min; after trimming, the blade is positioned in the trimming die, and the dirt on the blade surface is cleaned, and then the forging misalignment is checked to be 1.0mm, and the residual burrs: the residual burrs on one side of the blade body are 2.0mm, and the residual burrs at other positions are 1.5mm, and the existing defects are repaired in time to ensure that the forgings are defect-free after trimming.

[0068] It should be noted that the processes such as "grinding, shot blasting, lubrication" involved in the embodiments of the present application all adopt existing conventional processes, and are not specifically limited in this case, and the specific contents will not be repeated.

[0069] Example 2: Different from Example 1, in step S1, the two ends of the bar with a specification of Φ49.3×429mm are first measured to a size of 427mm, and chamfered to C3, and the end face is turned to a roughness of Ra3.2, and then loaded into a furnace at 1070°C, kept warm for 40 minutes, and then taken out of the furnace to obtain a billet.

[0070] Example 3: Different from Example 1, in step S1, the two ends of the bar with a specification of Φ50.7×431mm are first measured to a size of 429mm, and chamfered to C5, and the end face is turned to a roughness of Ra3.2, and then loaded into a furnace at 1090°C, kept warm for 80 minutes, and then taken out of the furnace to obtain a billet.

[0071] Embodiment 4: Different from Embodiment 1, in step S2, the mold is pre-treated, and the pre-treatment method is: using compressed air to blow away the dirt in the mold cavity, and spraying graphite inside the mold cavity.

[0072] Embodiment 5: Different from Embodiment 1, in step S2, the mold is pre-treated, and the pre-treatment method is: using compressed air to blow away the dirt in the mold cavity, and spraying graphite inside the mold cavity.

[0073] Example 6: Different from Example 1, in step S3, dirt on the surface of the pre-forging is removed by shot blasting at a shot blasting speed of 50 m / s and a shot blasting time of 10 min, and then the surface defects of the pre-forging are eliminated by grinding, and the surface of the pre-forging is cleaned by shot blasting again at a shot blasting speed of 50 m / s and a shot blasting time of 30 min, and then the pre-forging is placed in an electric furnace at a furnace temperature of 150°C and kept warm for 30 min, and then sprayed with glass lubricant after being taken out, wherein the grinding defects shall not exceed 2 / 3 of the machining allowance, and the grinding width shall be 6 times of the grinding depth.

[0074] Example 7: Different from Example 1, in step S3, dirt on the surface of the preforging is removed by shot blasting at a shot blasting speed of 100 m / s and a shot blasting time of 20 min, and then the preforging is polished to eliminate surface defects, and the surface of the preforging is cleaned by shot blasting again at a shot blasting speed of 100 m / s and a shot blasting time of 40 min, and then the preforging is placed in an electric furnace at a furnace temperature of 180°C for 40 min, and then sprayed with glass lubricant after being taken out; wherein, the polishing defect shall not exceed 2 / 3 of the machining allowance, and the polishing width shall be 6 times of the polishing depth.

[0075] Example 8: Different from Example 1, the electrostatic spraying parameters of graphite are: electrostatic high voltage is 1 kV, electrostatic current is 1 μA, output pressure is 0.05 MPa, flow rate is controlled at 50 mL / min, spray distance is 50 mm, mist width is 50 mm, and spraying time is 1 s.

[0076] Example 9: Different from Example 1, the electrostatic spraying parameters of graphite are: electrostatic high voltage is 100kV, electrostatic current is 100μA, output pressure is 0.1MPa, flow rate is controlled at 450mL / min, spray distance is 350mm, mist width is 450mm, and spraying time is 60s.

[0077] Embodiment 10: Different from Embodiment 1, in step S4, the forging is subjected to two-time die forging treatment under the condition of a final forging temperature of 950°C, and between the two-time die forging treatments, shot blasting is performed once at a shot blasting speed of 50m / s and a shot blasting time of 10min, grinding is performed, and a second shot blasting is performed at a shot blasting speed of 50m / s and a shot blasting time of 30min, and glass lubricant is sprayed, and then the pre-forged piece is placed in the mold cavity for die forging, and the striking energy of the two-time die forging treatment is 20% and 35% of the total striking energy of the equipment, respectively, the grinding defect is 2 / 3 of the machining allowance, and the grinding width is 6 times of the grinding depth;

[0078] Among them, during the electrostatic spraying process of glass lubricant, the electrostatic voltage is 3kV, the electrostatic current is 20μA, the output pressure is 0.5MPa, the flow rate is controlled at 200mL / min, the spraying distance is 150mm, the mist width is 220mm, and the spraying time is 1min.

[0079] Embodiment 11: Different from Embodiment 1, in step S4, the forging is subjected to two-time die forging treatment under the condition of a final forging temperature of 1000°C, and between the two-time die forging treatment, shot blasting is performed once at a shot blasting speed of 100m / s and a shot blasting time of 20min, grinding is performed, shot blasting is performed twice at a shot blasting speed of 100m / s and a shot blasting time of 340min, and glass lubricant with a thickness of 200μm is sprayed, and then the pre-forged piece is placed in the mold cavity for die forging, and the striking energy of the two-time die forging treatment is 40% and 55% of the total striking energy of the equipment respectively, the grinding defect is 2 / 3 of the machining allowance, and the grinding width is 6 times of the grinding depth;

[0080] Among them, during the electrostatic spraying process of glass lubricant, the electrostatic voltage is 50kV, the electrostatic current is 40μA, the output pressure is 0.8MPa, the flow rate is controlled at 300mL / min, the spraying distance is 200mm, the mist width is 300mm, and the spraying time is 5min.

[0081] Example 12: Different from Example 1, in step S4, the heating temperature of the first die forging treatment is 1070°C, and the holding time is 75 minutes; the heating temperature of the second die forging treatment is 1070°C, and the holding time is 75 minutes.

[0082] Example 13: Different from Example 1, in step S4, the heating temperature of the first fire die forging treatment is 1090°C, and the holding time is 150 min; the heating temperature of the second fire die forging treatment is 1090°C, and the holding time is 150 min.

[0083] Example 14: Different from Example 1, in step S4, the parameters of cold heating trimming are: heating temperature 860°C, insulation time 30 minutes.

[0084] Example 15: Different from Example 1, in step S5, the dirt on the surface of the target forging is removed by shot blasting at a shot blasting speed of 50 m / s and a shot blasting time of 30 min, and then the surface defects of the target forging are eliminated by grinding. The surface of the target forging is cleaned by shot blasting again at a shot blasting speed of 50 m / s and a shot blasting time of 30 min. The grinding defects shall not exceed 2 / 3 of the machining allowance, and the grinding width shall be 6 times of the grinding depth.

[0085] Example 16: Different from Example 1, in step S5, the dirt on the surface of the target forging is removed by shot blasting at a shot blasting speed of 100 m / s and a shot blasting time of 40 min, and then the surface defects of the target forging are eliminated by grinding. The surface of the target forging is cleaned by shot blasting again at a shot blasting speed of 100 m / s and a shot blasting time of 40 min. The grinding defects shall not exceed 2 / 3 of the machining allowance, and the grinding width shall be 6 times the grinding depth.

[0086] Example 17: Different from Example 1, in step S6, the furnace is charged at 800°C, then kept at 900°C for 100 minutes, oil-cooled to 22°C after being taken out of the furnace, then charged at 22°C, kept at 700°C for 950 minutes, air-cooled to below 40°C after being taken out of the furnace, charged again at 22°C, kept at 640°C for 950 minutes, air-cooled to below 40°C after being taken out of the furnace, and shot blasted to obtain the aircraft engine stator blades.

[0087] Example 18: Different from Example 1, in step S6, the furnace is charged at 900°C, then kept at 900°C for 120 minutes, taken out of the furnace and oil-cooled to 30°C, then charged at 30°C and kept at 710°C for 970 minutes, taken out of the furnace and air-cooled to below 40°C, charged again at 30°C and kept at 660°C for 970 minutes, taken out of the furnace and air-cooled to below 40°C, and then shot blasted to obtain the aircraft engine stator blades.

[0088] Example 19: Different from Example 1, the target forging surface after step S5 is processed is subjected to weld thinning and homogenization treatment. The weld thinning and homogenization treatment method is as follows: the weld of the target forging is hammered with a small arc-shaped hammer with a radius of about 9 mm, the hammering force is 2.5 N, the hammering rate is 120 times / min, and the hammering time is 25 s, so that the metal at the weld of the target forging is thinned and stretched to the surroundings, and then a layer of thermal insulation coating with a thickness of 2 μm is sprayed on the weld thinning part of the target forging, and the auxiliary frequency is 90 Hz and the current density is 12 A / cm 3 The alternating current was controlled for 6 minutes;

[0089] The thermal insulation coating comprises, by weight percentage, 8% of boron nitride powder, 15% of talc, 13% of silica aerogel, 7% of aluminum silicate, 2% of glass microspheres and the balance of waterborne epoxy resin;

[0090] The spraying method is supersonic flame thermal coating; during supersonic flame thermal spraying, the distance between the spray gun and the workpiece is adjusted to 210 mm, the spraying angle is 50°, and the flow rate is controlled at 250 mL / min.

[0091] Example 20: Different from Example 19, a small arc-shaped hammer with a radius of about 8 mm is used to hammer the weld of the target forging, the hammering force is 2N, the hammering rate is 100 times / min, and the hammering time is 20s, so that the metal at the weld of the target forging is thinned and stretched to the surroundings, and then a layer of thermal insulation coating with a thickness of 1 μm is sprayed on the thinned weld of the target forging, and an auxiliary frequency of 80 Hz and a current density of 5 A / cm 3 The alternating current was adjusted for 5 minutes.

[0092] Example 21: Different from Example 19, a small arc-shaped hammer with a radius of about 10 mm is used to hammer the weld of the target forging, the hammering force is 3N, the hammering rate is 140 times / min, and the hammering time is 30s, so that the metal at the weld of the target forging is thinned and stretched to the surroundings, and then a layer of thermal insulation coating with a thickness of 3μm is sprayed on the thinned weld of the target forging, and a frequency of 100Hz and a current density of 20A / cm are applied to assist 3 The alternating current was adjusted for 8 minutes.

[0093] Example 22: Different from Example 19, the thermal insulation coating includes, by mass percentage, 5% boron nitride powder, 10% talcum powder, 10% silica aerogel, 3% aluminum silicate, 1% glass microspheres and the remainder water-based epoxy resin.

[0094] Example 23: Different from Example 19, the thermal insulation coating includes, by mass percentage, 10% boron nitride powder, 20% talcum powder, 15% silica aerogel, 10% aluminum silicate, 3% glass microspheres and the remainder water-based epoxy resin.

[0095] Example 24: Different from Example 19, the process parameters of supersonic flame thermal spraying are: the distance between the spray gun and the workpiece is 200 mm, the spraying angle is 40°, and the flow rate is controlled at 50 mL / min.

[0096] Example 25: Different from Example 19, the process parameters of supersonic flame thermal spraying are: the distance between the spray gun and the workpiece is 220 mm, the spraying angle is 60°, and the flow rate is controlled at 450 mL / min.

[0097] Experimental Example: The description of this experimental example is based on the schemes described in Examples 1 to 25, and is intended to illustrate the practical application effect of the present invention. The appearance and mechanical properties of the aviation blades obtained in Examples 1 to 25 were tested respectively, and a comparative example was set.

[0098] The blade forgings produced by the method of Example 1 to Example 25 were 100% visually inspected. The surface quality of the blade forgings of Example 1 to Example 25 was good and there were no defects such as cracks and folds. The blades of Example 19 to Example 25 had better tensile strength and crack resistance, and were of higher quality than those of Example 1 to Example 18. There were slight cracks on the surface of Comparative Example 1 to Comparative Example 5, and the surface quality was not as good as that of Example 1 to Example 25, indicating that the method of Example 1 to Example 25 was better. The metallographic structure of the aviation blades obtained by Example 1 to Example 25 was observed, and the grain size was found to be 10 or less, and the distribution was uniform.

[0099] 1. Explore the influence of forming and manufacturing parameters on the mechanical properties of blades;

[0100] Table 1 Mechanical properties of stator blades of Examples 1 to 18 and Comparative Examples 1 to 4

[0101]

[0102]

[0103] Comparative Example 1: Different from Example 1, in step S2, the holding time of the third upset forging is consistent with the first and second times.

[0104] Comparative Example 2: Different from Example 1, in step S2, no pretreatment is performed on the mold.

[0105] Comparative Example 3: Different from Example 1, in step S3, the glass lubricant adopts a new glass lubricant (such as B2O3-SiO2-Al2O3-Na2O-TiO2 system).

[0106] Comparative Example 4: Different from Example 1, in step S4, the edge cutting method is cold edge cutting.

[0107] It can be seen from the data in Table 1 that, by comparing the data of Example 1, Example 2, Example 3 and Comparative Example 2, it can be obtained that the mechanical properties of the stator blades are reduced by not adjusting the holding time in Comparative Example 2. The main reason is that the effective thickness of the blank increases after the first two upset forgings. In order to ensure sufficient insulation at the forming position and reduce the material deformation resistance, thereby improving the efficiency of upset forging and the mechanical properties of the forging, the holding time of the third upset forging needs to be longer than the first two times.

[0108] From the data comparison of Example 1, Example 4, Example 5 and Comparative Example 2, it can be seen that if the mold is not pre-treated, the mechanical properties of the forging will also decrease. Graphite, as a common material, is often sprayed inside the mold cavity. Its main functions include lubrication, heat conduction and preventing mold sticking. Graphite has natural lubrication properties, and its crystal structure allows relative sliding between layers. Spraying graphite in the mold cavity can significantly reduce the friction between the mold and the molten metal, thereby improving the filling effect. Graphite also has excellent thermal conductivity, and its thermal conductivity is much higher than that of most metal materials, which means that the graphite layer can quickly conduct heat away, thereby accelerating the solidification process of the molten metal, which is crucial to the filling effect, because during the filling stage, the rapid solidification of the liquid material can help maintain its shape accuracy and further improve the filling effect of the blade, thereby improving the mechanical properties.

[0109] From the comparison of Example 1, Example 10, Example 11 and Comparative Example 3, it can be seen that the glass lubricant adopts a new glass lubricant by introducing titanium oxide, which further optimizes its viscosity and structural stability at high temperatures. The presence of titanium oxide can not only strengthen the network structure and reduce the viscosity, but also maintain a longer flow time at extremely high temperatures, and can also improve the mechanical properties of the stator blades to a certain extent. However, the effect is slightly weaker than that of GDS-17-1. This is because at high temperatures, the lubricating effect of GDS-17-1 at high temperatures can effectively control the microstructure of the metal blades and reduce surface defects and sub-surface damage caused by friction. These microstructural changes directly affect the mechanical properties of the material, such as strength, toughness and fatigue life. In addition, during high-temperature forging, the protective film formed by GDS-17-1 can prevent oxidation of the metal surface, thereby maintaining metal density and improving mechanical properties. Oxidation and loosening can lead to voids and cracks inside the material, seriously affecting its mechanical properties. The effective protection of GDS-17-1 avoids these problems. By reducing the friction between the mold and the workpiece, GDS-17-1 makes the stress more evenly distributed on the metal blade, avoiding defects caused by local stress concentration, which not only improves the overall mechanical properties of the blade, but also extends its service life. Compared with other common glass lubricants, GDS-17-1 performs well in terms of composition diversity, particle size control and environmental friendliness, and can adapt to a variety of complex high-temperature processing environments.

[0110] From the comparison of Example 1, Example 14 and Comparative Example 4, it can be seen that hot slicing and cold heated edge cutting have little effect on the mechanical properties of the stator blades, while the cold edge cutting in Comparative Example 4 also causes a significant decrease in the mechanical properties of the stator blades. This is because compared with cold cutting, cold heated edge cutting can reduce shear stress because it is carried out in a hot state, thereby reducing the generation of microcracks during cold cutting, further improving its mechanical properties, and considering the comprehensive cost, Example 1 is the optimal solution.

[0111] 2. Investigate the effect of weld thinning and homogenization treatment on the mechanical properties of stator blades

[0112] Table 2 Mechanical properties of stator blades of Example 1, Example 19 to Example 25, Comparative Example 5 to Comparative Example 7

[0113]

[0114]

[0115] Comparative Example 5: Different from Example 19, no alternating current is applied to the surface of the thermal insulation coating.

[0116] Comparative Example 6: Different from Example 19, no glass beads are added to the thermal insulation coating.

[0117] Comparative Example 7: Different from Example 19, the thermal insulation coating is sprayed by electrostatic spraying.

[0118] Conclusion: From the comparison of Example 1 and Examples 19 to 25, it can be seen that the stator blades after the weld thinning and homogenization treatment have significantly improved performance compared with Example 1, and can reach the best under the parameters of Example 19; this is because the weld thinning and homogenization treatment can improve the microstructure of the material by offsetting some weld shrinkage and reducing welding stress, reducing the thickness of the weld area, thereby improving the mechanical properties of the material; and from the data comparison of Examples 19 to 21 and Comparative Example 5, it can be seen that not applying alternating current during the spraying of the thermal insulation coating will also lead to the performance of the stator blades The main reason for the decrease is that the alternating current will generate a changing magnetic field in the molten metal. This magnetic field will generate a Lorentz force on the conductive molten metal, causing the molten metal to flow. This flow can significantly enhance the fluidity of the molten metal, making it easier to fill the complex-shaped mold cavity, especially in weak areas such as weld thinning. Electromagnetic stirring can effectively prevent shrinkage at the hot joint. At the same time, the electromagnetic field generated by the alternating current can refine the crystal structure of the molten metal, making the grains finer and more uniform. The principle of fine grain strengthening is that there are more smaller grain boundaries, which can better hinder the movement of dislocations, thereby improving The strength and hardness of the stator blades; in addition to electromagnetic stirring, the alternating current also generates heat through electromagnetic induction, which can compensate for the temperature drop of the molten metal during the solidification process, and further reduce the probability of casting defects such as cold shut and shrinkage; from the data comparison of Example 19, Example 22, Example 23 and Comparative Example 6, it can be seen that the performance of the blades obtained without adding glass microbeads to the thermal insulation coating is also reduced. The spherical glass microbeads have good fluidity and can effectively reduce the viscosity and internal stress of the coating, thereby improving the overall construction performance and reducing coating defects, further improving the performance of the stator blades. , the lack of glass microbeads will increase the viscosity of the coating, reduce its fluidity, and make it difficult to penetrate into parts with complex geometric shapes, which may lead to insufficient filling and affect the forming quality and detail integrity of the blades; from the comparison of Example 19, Example 24, Example 25 and Comparative Example 7, it can be seen that compared with supersonic flame thermal coating, the coating formed by electrostatic spraying is relatively loose. During the blade filling process, the loose coating has poor thermal insulation effect, and heat is more easily dissipated, which may lead to uneven temperature of the molten metal inside the blade, thereby affecting the filling effect, and defects such as cold shut and insufficient pouring may occur, thereby weakening its mechanical properties. In summary, Example 19 provides a method for preparing an engine stator blade with strong mechanical properties and good filling properties.

Claims

1. A forming and manufacturing method for aircraft engine stator blades, characterized in that: The following steps are involved: S1. Preprocessing First, the two ends of the bar material with the specification of Φ50±0.7×430±1mm are measured to a size of 428±1mm, and chamfered to C3-C5, and turned to an end surface roughness of ≤Ra3.2, and then loaded into a furnace at 1070-1090℃, and heat-treated for 40-80min before being taken out of the furnace to obtain a blank; S2. Upsetting treatment Under the condition of the final forging temperature of 950-1050°C, the blank is subjected to three upset forging treatments respectively, and air-cooled to room temperature after each upset forging treatment. After the first air cooling to room temperature, the forging is placed in a mold for step I forming, after the second air cooling to room temperature, the forging is placed in a mold for step II forming and step III forming, and after the third air cooling to room temperature, the forging is placed in a mold for step IV forming and step V forming to obtain a pre-forged part; S3, Level 1 defect handling Shot blasting is used to remove dirt on the surface of the preforgings, and then grinding is performed to eliminate defects on the surface of the preforgings. The surface of the preforgings is shot blasted again, and then the preforgings are placed in an electric furnace at a temperature of 150 to 180°C for 30 to 40 minutes, and then taken out and sprayed with glass lubricant; S4, die forging Under the condition of the final forging temperature of 950-1050℃, the forging is subjected to two-time die forging treatment, and one shot blasting, grinding, two-time shot blasting and lubrication treatment are performed in sequence between the two-time die forging treatments. The impact energy of the two-time die forging treatments is 30±10% and 45±10% of the total impact energy of the equipment respectively; heating treatment is performed before each die forging treatment, air cooling to room temperature is performed after the first die forging treatment, and hot trimming is performed after the second die forging treatment or air cooling is performed on a tray first, and then cold heating trimming is performed, and air cooling is performed after trimming to obtain the target forging; S5. Secondary defect handling Shot blasting removes dirt from the surface of the target forging, then polishing to eliminate defects on the surface of the target forging, and shot blasting again to clean the surface of the target forging; S6, solution aging treatment The furnace is charged at 800-900℃, and then kept at 900℃ for 100-120min, taken out of the furnace and oil-cooled to room temperature, then charged at room temperature and kept at 700-710℃ for 950-970min, taken out of the furnace and dispersedly air-cooled to below 40℃, charged again at room temperature and kept at 640-660℃ for 950-970min, taken out of the furnace and air-cooled to below 40℃, and shot blasted to obtain aircraft engine stator blades.

2. A forming and manufacturing method for an aircraft engine stator blade according to claim 1, characterized in that: In step S2, a heating treatment is performed before each upset treatment. The methods of the first upset forging treatment and the second upset forging treatment are: heating the forging to 1070-1090°C, keeping it warm for 40-80 minutes and then taking it out of the furnace; The method of the third upset forging treatment is: heating the forging to 1070-1090°C, keeping it warm for 53-106 minutes and then taking it out of the furnace, and cleaning the material when the keeping warm time is 80 minutes and after the keeping warm time is over.

3. The forming and manufacturing method of a stator blade of an aircraft engine according to claim 1, characterized in that: In step S2, the mold is pre-treated, and the pre-treatment method is: using compressed air to blow away the dirt in the mold cavity, and spraying graphite inside the mold cavity.

4. A method for forming and manufacturing an aircraft engine stator blade according to claim 3, characterized in that: The graphite is sprayed by electrostatic spraying; the electrostatic spray gun of the electrostatic spraying is the cathode, the metal film-forming substrate is the anode and is grounded, the electrostatic voltage is 1 to 100 kV, the electrostatic current is 1 to 100 μA, the output pressure is 0.05 to 0.1 MPa, the flow rate is controlled at 50 to 450 mL / min, the spray distance is 50 to 350 mm, the mist width is 50 to 450 mm, and the spraying time is 1 to 60 s.

5. The forming and manufacturing method of a stator blade of an aircraft engine according to claim 1, characterized in that: In step S3, the glass lubricant is GDS-17-1; the spraying method of the glass lubricant is electrostatic spraying; the electrostatic spray gun of the electrostatic spraying is the cathode, the metal film-forming substrate is the anode and is grounded, the electrostatic voltage is 3 to 50 kV, the electrostatic current is 20 to 40 μA, the output pressure is 0.5 to 0.8 MPa, the flow rate is controlled at 200 to 300 mL / min, the spray distance is 150 to 200 mm, the mist width is 220 to 300 mm, and the spraying time is 1 to 5 min.

6. The forming and manufacturing method of a stator blade of an aircraft engine according to claim 1, characterized in that: In step S4, the heating temperature of the first die forging treatment is 1070-1090°C, and the holding time is 75-150 minutes; the heating temperature of the second die forging treatment is 1070-1090°C, and the holding time is 75-150 minutes.

7. The method for forming and manufacturing an aircraft engine stator blade according to claim 1, characterized in that: In step S4, the parameters of the cold heating trimming are: heating temperature 850°C ± 10°C, holding time 15 to 30 minutes; after trimming, the blade is positioned in the trimming die, and dirt on the blade surface is cleaned, and then the forging misalignment is checked to be ≤1.0mm, and the residual burrs: the residual burrs on one side of the blade body are ≤2.0mm, and the residual burrs at other positions are ≤1.5mm, and the existing defects are repaired in time to ensure that the forgings are defect-free after trimming.

8. The method for forming and manufacturing an aircraft engine stator blade according to claim 1, characterized in that: After the step S5 is completed, the target forging surface is subjected to weld thinning and homogenization treatment. The weld thinning and homogenization treatment method is as follows: the weld of the target forging is hammered with a small arc-shaped hammer with a radius of about 8 to 10 mm, the hammering force is 2 to 3 N, the hammering rate is 100 to 140 times / min, and the hammering time is 20 to 30 seconds, so that the metal at the weld of the target forging is thinned and extended to the surroundings, and then a layer of thermal insulation coating with a thickness of 0.1 to 0.5 μm is sprayed on the weld thinning part of the target forging, and an auxiliary frequency of 80 to 100 Hz and a current density of 5 to 20 A / cm 3 The alternating current is adjusted for 5 to 8 minutes.

9. A method for forming and manufacturing an aircraft engine stator blade according to claim 8, characterized in that: The thermal insulation coating comprises, by mass percentage, 5-10% of boron nitride powder, 10-20% of talc, 10-15% of silicon dioxide aerogel, 3-10% of aluminum silicate, 1-3% of glass microspheres and the balance of waterborne epoxy resin.

10. The method for forming and manufacturing an aircraft engine stator blade according to claim 8, characterized in that: The thermal insulation coating is sprayed by supersonic flame thermal coating; the process parameters of the supersonic flame thermal spraying are: the distance between the spray gun and the workpiece is 200-220 mm, the spraying angle is 40-60°, and the flow rate is controlled at 50-450 mL / min.

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