Preparation method of unmanned fighter plane system pipeline

Abstract

The invention belongs to a metal surface treatment technology, and relates to a preparation method of an unmanned fighter system pipeline, in particular to surface treatment of a filler neck of the unmanned fighter system pipeline. According to the method, a hard anodizing technology is independently adopted for the filler neck, and a metal workpiece is subjected to anodic electrolysis treatment in sulfuric acid and deionized water, so that a compact aluminum oxide ceramic film layer with extremely high hardness is formed on the surface of the metal workpiece; the hard anodized film layer has a porous structure, which not only enhances the adsorption capacity of the film layer, but also can further improve the corrosion resistance and wear resistance of the film layer.

Description

Technical Field

[0001] The invention belongs to metal surface treatment technology and relates to a method for preparing pipelines of an unmanned fighter system, and in particular to surface treatment of a pipe nozzle of the pipeline of the unmanned fighter system. Technical Background

[0002] Unmanned combat aircraft (UCAVs) are becoming increasingly important. Not only can they operate in tandem with manned fighters, significantly enhancing the overall combat effectiveness of manned aircraft, but they also leverage their unique advantages to significantly increase attack flexibility and significantly enhance the intensity of firepower strikes. Meanwhile, an aircraft's piping system, while seemingly insignificant, is in fact of extraordinary significance. As a key component of the aircraft's power system, the piping system is responsible for safely and stably transporting fuel from the aircraft's fuel tanks to the engine, providing a solid foundation for the engine's continued stable operation and playing an indispensable role in the aircraft's safe flight and performance.

[0003] Chemical oxidation is currently used to treat the entire surface of the nozzles and piping in unmanned combat aircraft systems. Chemical oxidation involves a chemical reaction between a chemical medium and the metal surface, forming an oxide film. Chemical oxidation is commonly used for the surface treatment of aluminum and aluminum alloys, where specific chemical reagents are added to form a protective film on the metal surface. This oxide film is typically thin and soft, with relatively poor wear and corrosion resistance. This oxide film easily falls off during repeated disassembly or replacement of connected parts and piping, making it highly susceptible to thread damage.

[0004] Therefore, new surface treatment methods need to be studied for this type of nozzle to meet the needs of the aviation industry. Summary of the Invention

[0005] In view of the above technical problems, the present invention proposes a method for preparing the pipeline of an unmanned combat aircraft system. In this method, the pipe nozzle is hard anodized to form a dense and extremely hard aluminum oxide ceramic film on the surface.

[0006] In order to achieve the above objectives, the present invention adopts the following technical solutions.

[0007] A method for preparing pipelines of an unmanned combat aircraft system comprises the following steps: Step 1: Pre-treatment of the raw materials of the nozzle; Step 2: Apply glue to the welding area of ​​the nozzle in step 1; Step 3: degreasing, pickling, polishing, washing, hanging and fixing; Step 4: Hard anodize the nozzle in electrolyte. Initial stage: current density 0.5A / dm 2 , voltage 8-12V, gradually increased to 2.5A / dm 2, lasting 20-30 minutes; stable stage: current density 2.5-3.5A / dm 2 , voltage 30-40V, maintain temperature ≤ 2°C (forced cooling); obtain a nozzle with a hard anodized film; Step 5: Welding; Step 6: Apply glue to the hard anodized area of ​​the butt nozzle; Step 7: surface treatment; Step 8: Post-process the materials to obtain the unmanned combat aircraft system pipeline.

[0008] Furthermore, in step 1, the pre-processing of the raw materials includes cutting, bending, measuring, and removing excess.

[0009] Furthermore, in step 3, degreasing is performed using an alkaline cleaning agent (such as Na3PO4 2wt%, Na2CO3 1wt% or NaOH 0.5wt%) at a temperature of 40-50°C for 30-60 seconds.

[0010] Furthermore, in step 3, pickling is performed using a mixture of nitric acid (concentration 20 wt%) and hydrofluoric acid (concentration 3 wt%) for 0.2-0.5 minutes at a temperature of 20°C.

[0011] Furthermore, in step 3, the light emission is treated with a solution of sulfuric acid (concentration 230-270 g / L) + potassium permanganate (concentration 0.8-1.2 g / L) for 20-40 seconds.

[0012] Furthermore, in step 3, the water washing is performed by rinsing with running cold water until the water becomes neutral.

[0013] Furthermore, in step 3, the mounting and fixing is performed using a clamp to ensure good contact with the workpiece; the edges and corners need to be rounded (radius ≥ 0.5 mm).

[0014] Furthermore, in step 4, the thickness of the hard anodized film is 25-150 μm.

[0015] Furthermore, in step 4, the electrolyte is configured as follows: the main liquid component is sulfuric acid (H2SO4) with a concentration of 130-245 g / L, and oxalic acid (concentration 15 g / L) or organic acid can be added to improve the density of the membrane layer; temperature control: 0±2°C (a circulating cooling system is required to maintain a low temperature).

[0016] Furthermore, in step 7, the surface treatment is chemical oxidation of the entire pipeline.

[0017] Furthermore, in step 8, the material post-processing includes flaring, pressure testing, cleaning, labeling, and packaging.

[0018] Compared with the prior art, the present invention has the following beneficial effects.

[0019] 1. Hard anodizing (also known as hard anodizing or hard anodic electrophoretic coating) is used on individual butt-jointed nozzles. This involves electrolyzing the metal workpiece in sulfuric acid and deionized water to form a dense, extremely hard aluminum oxide ceramic film. Hard anodizing is based on an electrochemical oxidation process. By controlling parameters such as the electrolyte composition, concentration, temperature, and electrolysis conditions, an oxidation reaction occurs on the metal surface, forming the aluminum oxide ceramic film.

[0020] 2. The surface treatment of the nozzle is hard anodizing, and the surface treatment of the pipeline is chemical oxidation. Because two different surface treatment methods are used in the assembly of the same pipeline, the overall processing technology of this type of pipeline changes, and two additional gluing processes (chemical milling and protective glue) are required. Before hard anodizing, the welding area of ​​the nozzle is glued. Figure 2 , protect the welding area from film layer to prevent affecting the welding quality, in order to protect the hard anodized film layer when performing surface treatment on the pipeline, the hard anodized nozzle is coated with glue before chemical oxidation. Figure 4 .

[0021] 3. The hard anodized film has a porous structure, which not only enhances the adsorption capacity of the film, but also further improves its corrosion resistance and wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the pre-treatment diagram of step 1 in Example 1.

[0023] Figure 2 This is a picture of the pipe nozzle after hard anodizing in step 4 of Example 1.

[0024] Figure 3 This is a scanning electron microscope image of the butt-joint nozzle of Example 1 after hard anodizing.

[0025] Figure 4 This is the picture after welding in step 5 of Example 1.

[0026] Figure 5 This is a diagram of applying glue to the hard anodized area of ​​the butt nozzle in step 5 of Example 1.

[0027] Figure 6 This is a diagram of the entire pipeline after chemical oxidation in step 7 of Example 1.

[0028] Figure 7 This is the final product picture of Example 1. DETAILED DESCRIPTION

[0029] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] A method for preparing pipelines of an unmanned combat aircraft system comprises the following steps: Step 1: Pre-treatment of the raw materials of the nozzle; Step 2: Apply glue to the welding area of ​​the nozzle in step 1; Step 3: degreasing, pickling, polishing, washing, hanging and fixing; Step 4: Hard anodize the nozzle in electrolyte. Initial stage: current density 0.5A / dm 2 , voltage 8-12V, gradually increased to 2.5A / dm 2 , lasting 20-30 minutes; stable stage: current density 2.5-3.5A / dm 2 , voltage 30-40V, maintain temperature ≤ 2°C (forced cooling); obtain a nozzle with a hard anodized film; Step 5: Welding; Step 6: Apply glue to the hard anodized area of ​​the butt nozzle; Step 7: surface treatment; Step 8: Post-process the materials to obtain the unmanned combat aircraft system pipeline.

[0031] Furthermore, in step 1, the pre-processing of the raw materials includes cutting, bending, measuring, and removing excess.

[0032] Furthermore, in step 3, degreasing is performed by using an alkaline cleaning agent (such as Na3PO4 2wt%, Na2CO3 1wt% or NaOH 0.5wt%) to remove oil stains at a temperature of 40-50°C for 30-60 seconds.

[0033] Furthermore, in step 3, the pickling is performed using a mixture of nitric acid (concentration 20 wt%) and hydrofluoric acid (concentration 3 wt%) for 0.2-0.5 minutes at a temperature of 20°C.

[0034] Furthermore, in step 3, the light is treated with a solution of sulfuric acid (concentration 230-270 g / L) + potassium permanganate (concentration 0.8-1.2 g / L) to remove residual oxides on the surface for 20-40 seconds.

[0035] Furthermore, in step 3, water washing is performed by flushing with running cold water until the water is neutral to prevent residual liquid from affecting the quality of the oxide film.

[0036] Furthermore, in step 3, the mounting and fixing is performed using a clamp to ensure good contact with the workpiece to avoid tip discharge; the edges and corners need to be rounded (radius ≥ 0.5 mm) to prevent local current concentration from causing ablation.

[0037] Furthermore, in step 4, the thickness of the hard anodized film is 25-150 μm.

[0038] Furthermore, in step 4, the electrolyte is configured as follows: the main liquid component is sulfuric acid (H2SO4) with a concentration of 130-245 g / L, and oxalic acid (concentration 15 g / L) or organic acid can be added to improve the density of the membrane layer; temperature control: 0±2°C (a circulating cooling system is required to maintain a low temperature).

[0039] Furthermore, in step 7, the surface treatment is chemical oxidation of the entire pipeline.

[0040] Furthermore, in step 8, the material post-processing includes flaring, pressure testing, cleaning, labeling, and packaging.

[0041] Example 1.

[0042] A method for preparing pipelines of an unmanned combat aircraft system comprises the following steps: Step 1: Pre-processing of raw materials for nozzles: blanking, cutting raw materials and cutting corresponding processing lengths; bending, bending on a CNC pipe bender according to the digital model data (see Table 1); measuring, measuring the bent pipe with a measuring machine, marking the excess allowance after measurement; removing the excess allowance, cutting off the excess allowance (see Figure 1 ); Step 2: Glue application: Apply glue to the welding area of ​​the butt nozzle; Step 3: Use Na3PO42wt% alkaline cleaning agent to remove oil stains at 50°C for 50 seconds; use a mixture of nitric acid (concentration 20wt%) + hydrofluoric acid (concentration 3wt%) to remove the surface oxide film for 0.3 minutes at 20°C; use sulfuric acid (concentration 230g / L) + potassium permanganate (concentration 0.9g / L) solution to remove residual surface oxides for 40 seconds; rinse with running cold water until neutral to prevent residual liquid from affecting the quality of the oxide film; use a fixture to ensure good contact with the workpiece to avoid tip discharge, and round the edges and corners (radius ≥ 0.5mm) to prevent local current concentration from causing ablation; Step 4: Hard anodize the nozzle in electrolyte (raw material 5A03), initial stage: current density 0.5A / dm 2 , voltage 12V, gradually increased to 2.5A / dm 2 , lasting 25 minutes; stable stage: current density 3.5A / dm 2, voltage 30V, forced cooling to maintain temperature ≤ 2℃; obtain a nozzle with a hard anodized film (thickness 45μm); the electrolyte configuration is: the main liquid component is sulfuric acid (H2SO4) concentration 230g / L; the circulating cooling system maintains low temperature control: 0±2℃, (see Figure 2 , green is the glued area); Step 5, welding: matching welding parts, repair before welding, determine the welding position according to the drawing marking, (see Figure 4 ); Step 6, glue application: After welding, only glue is applied to the hard anodized area of ​​the butt nozzle. The green area is the glue application area. (See Figure 5 ); Step 7, surface treatment: chemical oxidation of the entire pipeline, (see Figure 6 ); Step 8, material post-processing: flaring, matching standard parts, spinning flaring at both ends of the pipe; pressure test, clean the inner and outer surfaces before pressure test, check the air tightness of the pipe; cleaning, repeatedly clean the inner and outer surfaces; marking, spray code the pipe fittings; packaging, packaging the pipe fittings to prevent excess; get the unmanned fighter system pipeline, (see Figure 7 ).

[0043] Table 1 Digital and analog data.

[0044] Wear resistance and corrosion resistance testing: 1. Wear resistance test 1. Test basis: PMJ-1 flat grinder test method in HB5057 standard.

[0045] 2. Test sample information: Name: Take-off nozzle (made of 5A06 aluminum alloy), with a copper content of less than or equal to 1%; State before the test: The net weight of the sample before the test is 100,000 mg.

[0046] 3. Testing process: Using PMJ-1 flat grinding machine, according to the process and parameters specified in HB5057 standard, the wear resistance test of hard anodized nozzle samples was carried out.

[0047] 4. Test results: The net weight of the sample after the test is 99992 mg.

[0048] 5. Result calculation and judgment: Calculation of wear loss: Wear loss = net weight before test - net weight after test, i.e. 100000 mg - 99992 mg = 8 mg; Judgment basis: The standard stipulates that the wear loss of aluminum alloy with a copper content of less than or equal to 1% shall not exceed 10mg; Judgment conclusion: The wear loss of the nozzle sample tested this time is 8mg, which is less than 10mg and meets the requirements of HB5057 standard.

[0049] 2. Corrosion resistance test 1. Test basis: HB5057 salt spray test.

[0050] 2. Test sample information: Name: Take-off nozzle (material: 5A06 aluminum alloy); Condition before test: good appearance.

[0051] 3. Testing process: The testing method shall refer to HB5362 and the salt spray test time shall not be less than 336 hours.

[0052] 4. Test results: No white or gray-black corrosion products were found.

[0053] 5. Result calculation and judgment: Judgment basis: No white or gray-black corrosion products shall appear; Judgment conclusion: The nozzle samples tested this time did not show any white or gray-black corrosion products, which meets the requirements of HB5362 standard.

Claims

1. A method for preparing pipelines of an unmanned combat aircraft system, characterized in that: The steps include: Step 1: Pre-treatment of the raw materials of the nozzle; Step 2: Apply glue to the welding area of ​​the nozzle in step 1; Step 3: degreasing, pickling, polishing, washing, hanging and fixing; Step 4: Hard anodize the nozzle in electrolyte. Initial stage: current density 0.5A / dm 2 , voltage 8-12V, gradually increased to 2.5A / dm 2 , lasting 20-30 minutes; stable stage: current density 2.5-3.5A / dm 2 , voltage 30-40V, maintain temperature ≤ 2°C; obtain a nozzle with a hard anodized film; Step 5: Welding; Step 6: Apply glue to the hard anodized area of ​​the butt nozzle; Step 7: surface treatment; Step 8: Post-process the materials to obtain the unmanned combat aircraft system pipeline.

2. The method for preparing pipelines of an unmanned combat aircraft system according to claim 1, characterized in that: In step 1, the pre-processing of raw materials includes cutting, bending, measuring, and removing excess.

3. The method for preparing pipelines of an unmanned combat aircraft system according to claim 1, characterized in that: In step 3, degreasing is performed using an alkaline cleaning agent at a temperature of 40-50° C. for 30-60 seconds.

4. The method for preparing pipelines of an unmanned combat aircraft system according to claim 1, characterized in that: In step 3, the pickling is performed by using a mixture of 20 wt% nitric acid and 3 wt% hydrofluoric acid for 0.2-0.5 minutes at a temperature of 20° C.; the light emitting is performed by treating with a solution of 230-270 g / L sulfuric acid and 0.8-1.2 g / L potassium permanganate for 20-40 seconds; and the water washing is performed by rinsing with running cold water until the surface is neutral.

5. The method for preparing pipelines of an unmanned combat aircraft system according to claim 1, characterized in that: In step 3, the mounting and fixing is to use a clamp to ensure good contact with the workpiece; the edges and corners need to be rounded.

6. The method for preparing pipelines of an unmanned combat aircraft system according to claim 1, characterized in that: In step 4, the thickness of the hard anodized film is 25-150 μm.

7. The method for preparing pipelines of an unmanned combat aircraft system according to claim 1, characterized in that: In step 4, the electrolyte is configured as follows: the main liquid component is sulfuric acid with a concentration of 130-245 g / L, and oxalic acid or organic acid with a concentration of 15 g / L can be added to improve the density of the membrane layer; the temperature is controlled at 0±2°C.

8. The method for preparing pipelines of an unmanned combat aircraft system according to claim 1, characterized in that: In step 7, the surface treatment is chemical oxidation of the entire pipeline.

9. The method for preparing pipelines of an unmanned combat aircraft system according to claim 1, characterized in that: In step 8, the material post-processing includes flaring, pressure testing, cleaning, labeling, and packaging.

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