A reinforced composite material for main landing gear of light aircraft and a manufacturing method thereof

Abstract

The invention discloses a reinforced composite material for a main landing gear of a light aircraft and a manufacturing method thereof. The main landing gear of the light aircraft is formed by integrated forging and forming of a 55CrSiA spring steel plate, and the surface hardness is 45HRC-51HRC after forging and heat treatment. The main landing gear of the light aircraft is divided into three parts: an upper section connected to the fuselage, a lower section connected to the tire structure, and a middle section connecting the upper section and the lower section. The main landing gear is wide at the top and narrow at the bottom, thick at the top and thin at the bottom. The surface is infiltrated with a cobalt, chromium, and titanium composite coating with a penetration layer depth of 15μm-18μm, and the cobalt, chromium, and titanium are derived from an alloy 6B cobalt-based alloy. The surface of the main landing gear is also cured with a layer of polyurethane-based corrosion-resistant coating formed by dip coating and drying. The main landing gear of the light aircraft is integrally forged, has excellent mechanical properties, high surface strength, good overall toughness, and strong surface corrosion resistance.

Description

Technical Field

[0001] The invention relates to the technical field of metal composite material processing, in particular to a reinforced composite material for a main landing gear of a light aircraft and a manufacturing method thereof. Background Art

[0002] The landing gear is one of the key components of an aircraft. It is the main load-bearing component when the aircraft slides on the ground during takeoff and landing. It is used to support the weight of the aircraft and absorb impact energy. It is required to have comprehensive mechanical properties such as high strength and high toughness.

[0003] The current landing gear production and manufacturing on the market is restricted by insufficient equipment conditions and technical capabilities, low material utilization, long production cycle, high cost, and it is difficult to obtain sufficient mechanical properties based on integrated molding.

[0004] Large-scale overall refinement is the development trend of landing gear outer tube forgings. A good preform shape is the key to ensuring the one-time overall forming of the forging. At the same time, subsequent heat treatment of the forging is a necessary means to achieve the comprehensive mechanical properties of the forging. However, this technology has not been applied to civil light aircraft.

[0005] Then, steel parts after forging and heat treatment generally tend to be depleted in surface elements and oxidized on the surface, which can bring safety hazards to the landing gear whose failure mostly originates from mechanical tearing on the surface. Therefore, if it is an integral forged landing gear, its surface strength should also be strengthened from a safety perspective.

[0006] In addition, as an important safety component of civil light aircraft that is outdoors almost all the time, its corrosion resistance is also of paramount importance.

[0007] Therefore, there is an urgent need in the market for a reinforced composite material for a main landing gear of a light aircraft which is formed by one-step integral forging, has excellent mechanical properties, high surface strength, good overall toughness, and strong surface corrosion resistance, and a manufacturing method thereof. Summary of the invention

[0008] The present invention aims to provide a reinforced composite material for a main landing gear of a light aircraft which is integrally forged, has excellent mechanical properties, high surface strength, good overall toughness and strong surface corrosion resistance, and a manufacturing method thereof.

[0009] In order to achieve the above object, the present invention adopts the following technical solution: A method for manufacturing a reinforced composite material for a main landing gear of a light aircraft, comprising the following stages:

[0010] S1: Raw material preparation

[0011] ① Raw material preparation: prepare 55CrSiA spring steel plate with a thickness of 1.5mm-2.5mm thicker than the maximum thickness of the design size;

[0012] ② Preparation of auxiliary materials and equipment: prepare two low-temperature resistance furnaces, two medium-temperature resistance furnaces, one glow ion infiltration metal furnace, one set of forging dies for hot bending die pressing with upper and lower dies, one set of forging dies for hot rolling die pressing with upper and lower dies, sufficient argon gas, sufficient alloy 6B cobalt-based alloy, sufficient polyvinyl pyrrolidone solution with a solute mass of 3%, sufficient polyvinyl alcohol solution with a solute mass of 3%, sufficient 30% glycidoxypropyl trimethoxysilane hydrolyzed resin, sufficient benzotriazole, sufficient water-based polyurethane resin, sufficient glutaraldehyde, sufficient polyurethane resin leveling agent, sufficient polyurethane resin defoamer, sufficient polyurethane resin surfactant, sufficient deionized water, and solvent tank;

[0013] S2: Forging composite two-stage tempering

[0014] ① Mechanically cutting the spring steel plate prepared in step ① of stage S1 into a width matching the width of the main landing gear to obtain the original steel plate of the main landing gear;

[0015] ② Place the original main landing gear steel plate obtained in step ① in a resistance furnace, heat it to 920°C-940°C, and keep it warm for 40min-45min to obtain a heavy solid solution steel plate; at the same time, prepare a resistance furnace, heat it to 860°C-880°C, and obtain a preparatory electric furnace;

[0016] ③ Take out the heavy solid solution steel plate obtained in step ②, and immediately perform hot bending and pressing by means of up and down hot bending, with a deformation amount of 1.5°-2° each time, and repeat the process of pressing three times, then returning to the furnace for heating for 15min-18min, and then pressing three times again, until the heavy solid solution steel plate is forged into a ∫ shape matching the design contour of the main landing gear, to obtain a pre-solidified steel plate;

[0017] ④ Place the pre-consolidated steel plate obtained in step ③ into the pre-electric furnace prepared in step ②, maintain the temperature, heat for 25min-35min, then take it out, and still forge the pre-consolidated steel plate into a shape that matches the designed main landing gear shape, which is wide at the top and narrow at the bottom, thick at the top and thin at the bottom, by a deformation amount of 0.15mm-0.2mm each time, in the manner of upper and lower pressing. Compared with the designed size, the thickness and width directions of the shape are uniformly enlarged by 0.7mm-0.9mm, that is, the single-side contour size is increased by 0.35mm-0.45mm, to obtain a forging blank; at the same time, prepare a resistance furnace heated to 300℃-310℃ to obtain a tempering furnace;

[0018] ⑤ Transfer the forged blank obtained in step ④ to the first-stage tempering furnace prepared in step ④ within no more than 2 minutes after forging is completed, keep it warm for 2h-2.5h, then take it out of the furnace and air-cool it to room temperature, then put it into the first-stage tempering furnace again, continue to keep it warm for 2h-2.5h, then take it out and air-cool it to obtain a first-stage tempered forged blank; at the same time, prepare a resistance furnace heated to 200℃-220℃ to obtain a second-stage tempering furnace;

[0019] ⑥ Transfer the first-stage tempered forging blank obtained in step ⑤ to the second-stage tempering furnace prepared in step ⑤ within 3 hours after the first-stage tempering is completed, keep it warm for 8h-10h, take it out and air-cool it to complete the second-stage tempering, and detect the surface hardness of 40HRC-45HRC as a qualified product to obtain a heat-treated forging blank;

[0020] ⑦ The heat-treated forged blank obtained in step ⑥ is uniformly machined on four sides according to the final design size of the main landing gear, the excess is removed, and then the surface is polished, the sharp edge is rounded to R1mm-R1.2mm, and the burrs are removed to obtain a prefabricated landing gear;

[0021] S3: Surface metallization

[0022] ① Place the prefabricated landing gear obtained in step ⑦ of stage S2 in the glow ion infiltration furnace prepared in step ② of stage S1, with the wide first surface facing the emission source, and the distance between the surface and the emission source is controlled to be 8mm-10mm; the furnace uses the alloy 6B cobalt-based alloy prepared in step ② of stage S1 as the infiltration source, and evacuates the furnace to 1×10 -4 Pa-1×10 -3 Pa, then fill with argon until the pressure in the furnace is 22Pa-28Pa, increase the cathode voltage to 380V-420V, and maintain for 8min-9min to complete surface activation; then raise the temperature in the furnace to 840℃-850℃, continue to introduce argon until the pressure is 42Pa-45Pa, increase the source voltage to 850V-900V, adjust the cathode voltage to 350V-400V, maintain for 150min-170min, and then evacuate to 1×10 -1 Pa-1Pa, cooled to room temperature and taken out of the furnace to obtain a single-surface infiltrated metal drop stand;

[0023] ② Open the furnace and flip the single-surface metal-infiltrated landing frame obtained in step ①, so that the wide second surface of the single-surface metal-infiltrated landing frame faces the emission source, and repeat step ① to obtain a surface metal-infiltrated landing frame;

[0024] S4: Surface corrosion resistance treatment

[0025] ① The polyvinyl pyrrolidone solution prepared in step ② of stage S1, 3% polyvinyl alcohol solution, glycidoxypropyl trimethoxysilane hydrolyzed resin, and waterborne polyurethane resin are uniformly mixed in a mass ratio of 5-5.2:5-5.2:3-3.1:9-9.3, and then 0.3%-0.32% of glutaraldehyde, 0.02%-0.03% of benzotriazole, 0.2%-0.3% of polyurethane leveling agent, 0.2%-0.3% of polyurethane defoamer, and 0.2%-0.3% of polyurethane surfactant are added based on the total mass of the mixed solution to obtain a surface treatment solvent;

[0026] ②Put the surface treatment solvent obtained in step ① into the solvent tank prepared in step ② of stage S1, and at the same time heat a low-temperature resistance furnace to 95℃-98℃ for preparation, and then completely immerse the surface-diffused metal landing gear obtained in step ② of stage S3 into the surface treatment solvent in the heating tank, treat for 8min-10min, then take it out and place it in a low-temperature resistance furnace for drying to obtain the main landing gear of the light aircraft.

[0027] The main landing gear of a light aircraft manufactured according to the above method is made of 55CrSiA spring steel plate after integrated forging and processing. After forging and heat treatment, the surface hardness is 40HRC-45HRC. It is divided into three parts: an upper section connected to the fuselage, a lower section connected to the tire structure, and a middle section connecting the upper section and the lower section. It is wide at the top and narrow at the bottom, thick at the top and thin at the bottom. The surface is infiltrated with a cobalt, chromium, and titanium composite coating with a penetration layer depth of 15μm-18μm, and the cobalt, chromium, and titanium are derived from the alloy 6B cobalt-based alloy. The surface of the main landing gear is also solidified with a layer of polyurethane-based corrosion-resistant coating formed by dipping and drying.

[0028] Compared with the prior art, the present invention has the following advantages due to the adoption of the above technical solutions: (1) The present invention is different from the current manufacturing processes in the civil aviation field on the market. Due to the limitations of technology, cost, and processing conditions in the prior art, the relevant technologies involved in the present invention have not been applied in the prior art. In particular, the entire comprehensive technical solution involved in the present invention is an industrial technology with high material utilization and controllable cost for batch production of light aircraft in the civil aviation field to which the present invention is applicable. (2) The one-piece composite molding of the present invention integrates the performance of forging, heat treatment, surface metal infiltration strengthening and surface protection, and obtains an overall tensile strength of 1610MPa-1830MPa, a yield strength of 1380MPa-1450MPa, a surface hardness of 550HV-680HV, a matrix hardness of 40HRC-45HRC, and a life of up to 70,000 times. The production cycle from feeding to manufacturing only takes about 1 month, the elongation is 17%-19%, the elongation at break is 69.5%-82.3%, the surface water contact angle is 3°-6°, and the water resistance can obtain a residual rate of more than 90%. According to the national standard test characterization, the bonding strength between the surface film layer and the matrix is ​​level 0.(3) The four processing methods of the present invention are not simply physically superimposed. Each process method has been adjusted according to the common process parameters and steps in the field to meet the needs of the present invention, as follows: during forging, the forging heating temperature is lowered, the heating and heat preservation time is extended, and the single deformation is reduced. It is also divided into two-stage temperature forging, bending the steel plate at high temperature and extruding and deforming the steel plate at a slightly lower temperature, so that the original uniform structure, uniform grain size, relatively refined grains, forging streamline and complete forgings can be obtained; then the heat treatment process is divided into two stages, including two medium-temperature tempering and one low-temperature stress relief tempering. Compared with the conventional process, one more round of medium-temperature tempering and stress relief tempering is added, a total of two temperings, so that less residual quenched martensite is obtained, the future organizational stress is minimized, and the stress-released parts are obtained, which provides conditions for the high life of the subsequent landing gear; then, pure mechanical processing without hydrogen participation is used to remove the excess forming, The machining allowance is smaller than that of the prior art (the conventional technical solution in this field is to leave at least 0.5mm on one side after forging to remove the surface heat-affected zone). This is to ensure that there is still a layer of extremely slightly element-depleted and decarburized affected zone on the metal surface, laying the foundation for the subsequent metal infiltration process. The dimensional parameters of this heat treatment connected with machining are different from those of the existing conventional solutions; followed by surface infiltration treatment of the cobalt-based alloy under vacuum argon protection, which not only compensates for surface defects and fills surface micropores, but also improves surface integrity and reduces the tendency of surface stress concentration. Finally, the argon protection maintained at a certain pressure during furnace cooling is to maximize the guarantee that the elements infiltrated on the surface do not seep out at high temperatures. At the same time, the thermal stress of the workpiece cooled down by the furnace is minimized. This is also a process parameter different from the prior art; the final surface treatment is a hydrophilic polyurethane-based composite coating, which further improves the surface integrity and reliability of the landing gear. (4) In the process method adopted by the present invention, it seems that forging, heat treatment, surface glow metalizing and the final surface dip coating and drying seem to increase the cost a lot, but because the landing gear of the present invention is a completely symmetrical lath structure, all these process methods can be applied in batches, that is, multiple landing gears can be processed at one time. It is calculated that the cost of each landing gear increases by about 230 yuan to 250 yuan per piece compared with the prior art, that is, the cost of a single machine does not exceed 500 yuan, which is not too much for a light aircraft, but can greatly improve the safety, reliability and service life of the aircraft. Therefore, the present invention has the characteristics of integral forging, excellent mechanical properties, high surface strength, good overall toughness and strong surface corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the present invention;

[0030] Figure 2 It is a schematic diagram of the present invention after distribution;

[0031] In the figure: lower section 1, middle section 2, upper section 3. DETAILED DESCRIPTION

[0032] Embodiment 1:

[0033] ① Prepare 55CrSiA spring steel plates that are 1.5mm-2.5mm thicker than the maximum thickness of the design size; prepare two low-temperature resistance furnaces, two medium-temperature resistance furnaces, one glow ion infiltration metal furnace, a set of forging dies for hot bending die pressing with upper and lower dies, a set of forging dies for hot rolling die pressing with upper and lower dies, sufficient argon gas, sufficient alloy 6B cobalt-based alloy, sufficient polyvinyl pyrrolidone solution with a solute mass of 3%, sufficient polyvinyl alcohol solution with a solute mass of 3%, sufficient 30% glycidoxypropyl trimethoxysilane hydrolyzed resin, sufficient benzotriazole, sufficient water-based polyurethane resin, sufficient glutaraldehyde, sufficient polyurethane resin leveling agent, sufficient polyurethane resin defoaming agent, sufficient polyurethane resin surfactant, sufficient deionized water, and solvent tank;

[0034] ② Mechanically cut the spring steel plate into a width that matches the width of the main landing gear to obtain the original steel plate of the main landing gear; place the original steel plate of the main landing gear in a resistance furnace and heat it to 920℃

[0035] -940℃, keep warm for 40min-45min to obtain a heavy solid solution steel plate; at the same time, prepare a resistance furnace, heat it to 860℃-880℃ to obtain a preparatory electric furnace;

[0036] ③ Take out the heavy solid solution steel plate, and immediately perform hot bending and pressing by means of up and down hot bending, with a deformation of 1.5°-2° each time, and repeat the process of pressing three times, then returning to the furnace for heating for 15min-18min, and pressing three times again, until the heavy solid solution steel plate is forged into a ∫ shape matching the design contour of the main landing gear, and a pre-solidified steel plate is obtained;

[0037] ④ Place the pre-consolidated steel plate into the pre-electric furnace prepared in step ②, maintain the temperature, heat for 25min-35min, then take it out, and still forge the pre-consolidated steel plate into a shape that matches the designed main landing gear shape, which is wide at the top and narrow at the bottom, thick at the top and thin at the bottom, by a deformation amount of 0.15mm-0.2mm each time, in the manner of upper and lower pressing. Compared with the designed size, the thickness and width directions of this shape are uniformly enlarged by 0.7mm-0.9mm, that is, the single-side contour size is increased by 0.35mm-0.45mm, to obtain a forging blank; at the same time, prepare a resistance furnace heated to 300℃-310℃ to obtain a tempering furnace;

[0038] ⑤ Transfer the forged blank to a first-stage tempering furnace within 2 minutes after forging is completed, keep it warm for 2h-2.5h, then take it out of the furnace and air-cool it to room temperature, then put it into the first-stage tempering furnace again, keep it warm for 2h-2.5h, take it out and air-cool it to obtain a first-stage tempered forged blank; at the same time, prepare a resistance furnace with a temperature rise to 200℃-220℃ to obtain a second-stage tempering furnace;

[0039] ⑥ Transfer the first-stage tempering forging blank to the second-stage tempering furnace prepared in step ⑤ within 3 hours after the first-stage tempering is completed, keep it warm for 8 hours to 10 hours, take it out and air-cool it to complete the second-stage tempering. The surface hardness of 40HRC-45HRC is tested as a qualified product, and the heat-treated forging blank is obtained;

[0040] ⑦ The heat-treated forged blank is uniformly machined on all four sides according to the final design size of the main landing gear, the excess is removed, and then the surface is polished, the sharp edge is rounded to R1mm-R1.2mm, and the burrs are removed to obtain the prefabricated landing gear;

[0041] ⑧Put the prefabricated landing gear in a glow ion infiltration furnace, with the wide first surface facing the emission source, and the distance between the surface and the emission source is controlled to be 8mm-10mm; the furnace uses the alloy 6B cobalt-based alloy prepared in step ② of stage S1 as the infiltration metal source, and the furnace is evacuated to 1×10 -4 Pa-1×10 -3 Pa, then fill with argon gas to a pressure of 22Pa-28Pa in the furnace, and increase the cathode voltage to

[0042] 380V-420V, hold for 8min-9min to complete surface activation; then raise the temperature in the furnace to 840℃-850℃, continue to introduce argon gas to a pressure of 42Pa-45Pa, raise the source voltage to 850V-900V, adjust the cathode voltage to 350V-400V, hold for 150min-170min, and then evacuate to 1×10 -1 Pa-1Pa, cool down to room temperature with the furnace and take out of the furnace to obtain a single-surface metal-infiltrated landing frame; open the furnace and flip the single-surface metal-infiltrated landing frame so that the wide second surface of the single-surface metal-infiltrated landing frame faces the emission source, repeat this step to obtain a surface metal-infiltrated landing frame;

[0043] ⑨ The polyvinyl pyrrolidone solution, 3% polyvinyl alcohol solution, glycidoxypropyl trimethoxysilane hydrolyzed resin, and waterborne polyurethane resin are uniformly mixed in a mass ratio of 5-5.2:5-5.2:3-3.1:9-9.3, and then 0.3%-0.32% of glutaraldehyde, 0.02%-0.03% of benzotriazole, 0.2%-0.3% of polyurethane leveling agent, 0.2%-0.3% of polyurethane defoamer, and 0.2%-0.3% of polyurethane surfactant are added according to the total mass of the mixed solution to obtain a surface treatment solvent; the surface treatment solvent obtained in step ① is put into the solvent tank prepared in step ② of stage S1, and a low-temperature resistance furnace is heated to 95°C-98°C for preparation; then the surface-infiltrated metal landing gear is completely immersed in the surface treatment solvent in the heating tank, treated for 8min-10min, and then taken out and placed in a low-temperature resistance furnace for drying to obtain a main landing gear for a light aircraft.

[0044] The main landing gear of a light aircraft manufactured according to the method of this embodiment has a tensile strength of 1610MPa-1830MPa, a yield strength of 1380MPa-1450MPa, a surface hardness of 550HV-680HV, and a take-off and landing life of up to 70,000 times. The production cycle from feeding to manufacturing only takes about 1 month, the elongation is 17%-19%, the elongation at break is 69.5%-82.3%, the surface water contact angle is 3°-6°, and the water resistance can obtain a residual rate of more than 90%. According to the national standard test characterization, the bonding strength between the surface film layer and the substrate is level 0.

[0045] The above description of the disclosed embodiments is intended only to enable those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for manufacturing a reinforced composite material for a main landing gear of a light aircraft, characterized in that The following phases are included: S1: Raw material preparation ① Raw material preparation: prepare 55CrSiA spring steel plate 1.5mm-2.5mm thicker than the maximum thickness of the design size; ② Preparation of auxiliary materials and equipment: prepare two low-temperature resistance furnaces, two medium-temperature resistance furnaces, one glow ion infiltration metal furnace, a set of upper and lower molds for hot bending molding of parts, a set of upper and lower molds for hot rolling molding of parts, sufficient argon gas, sufficient 6B cobalt-based alloy, sufficient polyvinyl pyrrolidone solution with a solute mass of 3%, sufficient polyvinyl alcohol solution with a solute mass of 3%, sufficient glycidoxypropyl trimethoxysilane hydrolyzed resin, sufficient benzotriazole, sufficient water-based polyurethane resin, sufficient glutaraldehyde, sufficient polyurethane resin leveling agent, sufficient polyurethane resin defoaming agent, sufficient polyurethane resin surfactant, sufficient deionized water, and solvent tank; S2: Forging composite two-stage tempering ① Mechanically cutting the spring steel plate prepared in step ① of stage S1 into a width matching the width of the main landing gear to obtain the original steel plate of the main landing gear; ② Place the original main landing gear steel plate obtained in step ① in a resistance furnace, heat it to 920°C-940°C, and keep it warm for 40min-45min to obtain a heavy solid solution steel plate; at the same time, prepare a resistance furnace, heat it to 860°C-880°C, and obtain a preparatory electric furnace; ③ Take out the heavy solid solution steel plate obtained in step ②, and immediately perform hot bending and pressing by means of up and down hot bending, with a deformation amount of 1.5°-2° each time, and repeat the process of pressing three times, then returning to the furnace for heating for 15min-18min, and then pressing three times again, until the heavy solid solution steel plate is forged into a ∫ shape matching the design contour of the main landing gear, to obtain a pre-solidified steel plate; ④ Place the pre-consolidated steel plate obtained in step ③ into the pre-electric furnace prepared in step ②, maintain the temperature, heat for 25min-35min, then take it out, and still forge the pre-consolidated steel plate into a shape that matches the designed main landing gear shape, which is wide at the top and narrow at the bottom, thick at the top and thin at the bottom, by a deformation amount of 0.15mm-0.2mm each time, in the manner of upper and lower pressing. Compared with the designed size, the thickness and width directions of the shape are uniformly enlarged by 0.7mm-0.9mm, that is, the single-side contour size is increased by 0.35mm-0.45mm, to obtain a forging blank; at the same time, prepare a resistance furnace heated to 300℃-310℃ to obtain a tempering furnace; ⑤ Transfer the forged blank obtained in step ④ to the first-stage tempering furnace prepared in step ④ within no more than 2 minutes after forging is completed, keep it warm for 2h-2.5h, then take it out of the furnace and air-cool it to room temperature, then put it into the first-stage tempering furnace again, continue to keep it warm for 2h-2.5h, then take it out and air-cool it to obtain a first-stage tempered forged blank; at the same time, prepare a resistance furnace heated to 200℃-220℃ to obtain a second-stage tempering furnace; ⑥ Transfer the first-stage tempered forging blank obtained in step ⑤ to the second-stage tempering furnace prepared in step ⑤ within 3 hours after the first-stage tempering is completed, keep it warm for 8h-10h, take it out and air-cool it to complete the second-stage tempering, and detect the surface hardness of 40HRC-45HRC as a qualified product to obtain a heat-treated forging blank; ⑦ The heat-treated forged blank obtained in step ⑥ is uniformly machined on four sides according to the final design size of the main landing gear, the excess is removed, and then the surface is polished, the sharp edge is rounded to R1mm-R1.2mm, and the burrs are removed to obtain a prefabricated landing gear; S3: Surface metallization ① Place the prefabricated landing gear obtained in step ⑦ of stage S2 in the glow ion infiltration furnace prepared in step ② of stage S1, with the first wide surface facing the emission source, and the distance between the surface and the emission source is controlled to be 8mm-10mm; the furnace uses the 6B cobalt-based alloy prepared in step ② of stage S1 as the infiltration source, and evacuates the furnace to a vacuum of 1×10 -4 Pa-1×10 -3 Pa, then fill with argon until the pressure in the furnace is 22Pa-28Pa, increase the cathode voltage to 380V-420V, and maintain for 8min-9min to complete surface activation; then raise the temperature in the furnace to 840℃-850℃, continue to introduce argon until the pressure is 42Pa-45Pa, increase the source voltage to 850V-900V, adjust the cathode voltage to 350V-400V, maintain for 150min-170min, and then evacuate to 1×10 -1 Pa-1Pa, cooled to room temperature and taken out of the furnace to obtain a single-surface infiltrated metal drop stand; ② Open the furnace and flip the single-surface metal-infiltrated landing frame obtained in step ①, so that the wide second surface of the single-surface metal-infiltrated landing frame faces the emission source, and repeat step ① to obtain a surface metal-infiltrated landing frame; S4: Surface corrosion resistance treatment ① The polyvinyl pyrrolidone solution, polyvinyl alcohol solution, glycidoxypropyl trimethoxysilane hydrolyzed resin, and waterborne polyurethane resin prepared in step ② of stage S1 are uniformly mixed in a mass ratio of 5-5.2:5-5.2:3-3.1:9-9.3, and then glutaraldehyde, benzotriazole, polyurethane leveling agent, polyurethane defoaming agent, and polyurethane surfactant are added according to the total mass of the mixed solution to obtain a surface treatment solvent; ②Put the surface treatment solvent obtained in step ① into the solvent tank prepared in step ② of stage S1, and at the same time heat a low-temperature resistance furnace to 95℃-98℃ for preparation, and then completely immerse the surface-diffused metal landing gear obtained in step ② of stage S3 into the surface treatment solvent in the heating tank, treat for 8min-10min, then take it out and place it in a low-temperature resistance furnace for drying to obtain the main landing gear of the light aircraft.

2. The main landing gear of a light aircraft manufactured by the manufacturing method of reinforced composite materials for the main landing gear of a light aircraft according to claim 1, characterized in that: The main landing gear of the light aircraft is formed by forging 55CrSiA spring steel plates and then processing them. After forging and heat treatment, the surface hardness is 40HRC-45HRC. The main landing gear is divided into three parts: an upper section (3) connected to the fuselage, a lower section (1) connected to the tire structure, and a middle section (2) connecting the upper section (3) and the lower section. The main landing gear is wide at the top and narrow at the bottom, thick at the top and thin at the bottom. The surface is infiltrated with a cobalt, chromium and titanium composite coating with a penetration layer depth of 15μm-18μm, and the cobalt, chromium and titanium are derived from a 6B cobalt-based alloy. The surface of the main landing gear is also cured with a layer of polyurethane-based corrosion-resistant coating formed by dipping and drying.

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