Preparation method of wear-resistant lubricating film layer of aviation shaft part

Abstract

The invention discloses a preparation method of a wear-resistant lubricating film layer of an aviation shaft part. The preparation method comprises the following steps: finishing the surface of the aviation shaft part; cleaning greasy dirt on the surface of the part; a protection tool is used for shielding the surface of the part without film deposition; hanging the part to a hearth of vacuum coating equipment; preparing a NiCr, Cr and W metal adhesion layer on the surface of the undercarriage by magnetron sputtering; preparing a diamond-like carbon film layer on the metal adhesion layer by using acetylene by using a plasma enhanced chemical vapor deposition method; the diamond-like carbon film layer has a gradient transition structure of NiCr, a NiCr / Cr mixed layer, a Cr / W mixed layer, a W / Cr mixed layer and a DLC functional layer, the prepared diamond-like carbon film layer is uniform, compact, excellent in wear resistance and high in controllability of the technological process, the thickness of the film layer is 3-6 microns, the hardness reaches HV2000 or above, the friction coefficient is lower than 0.2, and the diamond-like carbon film layer is suitable for being used as a high-temperature-resistant coating. And the use requirements of wear resistance and lubrication of shaft parts are met.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation parts processing, and in particular relates to a method for preparing a wear-resistant lubricating film layer of aviation shaft parts. Background Art

[0002] During the use of aviation shaft parts, there are heavy loads of rotation and vibration, which lead to sliding wear, fretting wear and pitting wear, causing parts to get stuck, reducing the reliability and service life of parts. Therefore, it is necessary to prepare a film layer with high hardness, low friction coefficient, high bonding strength and good chemical stability for aviation shaft parts to improve wear resistance and increase service life.

[0003] Shaft parts require high assembly precision, and the cost of replacing new parts or repairing them after wear is high. The current wear-resistant protection method for aviation shaft parts is electroplating hard chrome. This process uses a large amount of hexavalent chromium, which has the problems of high toxicity and high pollution; there are a large number of microcracks in the hard chrome layer, which affects the sealing of parts with sealing requirements; the internal stress of the hard chrome layer is high, and this process greatly reduces the fatigue strength of the parts; the electroplated hard chrome coating has poor uniformity, and the coating thickness needs to be at least 25 microns, which has a great impact on the assembly of parts. Post-plating grinding is often used to ensure the accuracy and roughness of parts, which not only increases the process cycle but also has the quality risk of chromium collapse.

[0004] Based on the above problems, aviation shaft parts urgently need a high-quality, efficient and environmentally friendly new process to replace electroplated hard chrome and solve the lubrication, wear and sealing problems of shaft parts. In recent years, with the development of manufacturing technology, high-hardness hard film layers have shined in the manufacturing field, such as TiN, CrN, CrAlN, c-BN, etc. These hard films have great potential to replace electroplated hard chrome, but their application in aviation shafts has problems such as too high process temperature, low film bonding strength, high friction coefficient, and poor corrosion resistance. Diamond-like carbon film is mainly composed of SP with diamond structure. 3 Hybridized carbon atoms and sp in graphite structure 2 It is composed of carbon atoms and has the advantages of high hardness, low friction coefficient, acid and alkali resistance. It is an ideal friction and wear protection material. Summary of the invention

[0005] In order to overcome the above-mentioned shortcomings, the inventor of the present invention has continuously reformed and innovated through long-term exploration and attempts, multiple experiments and efforts, and proposed a wear-resistant lubricating film layer for aviation shaft parts and a preparation method thereof. The film layer bonding strength is improved and the process temperature is reduced through structural regulation and process regulation to meet the application requirements of aviation shaft parts. The wear-resistant lubricating film layer structure of aviation shaft parts includes NiCr, NiCr / Cr mixed layer, Cr / W mixed layer, W / Cr mixed layer, and DLC functional layer (diamond-like carbon functional layer). The layer-by-layer alternation and gradual transition method is adopted to gradually transition from the metal matrix to the DLC functional layer to balance the performance differences between different layers. The prepared wear-resistant lubricating film layer has a uniform and dense structure, good bonding strength with the matrix, low process temperature, and excellent wear resistance and friction reduction performance. The process is highly controllable, the total thickness of the film layer is 3μm to 6μm, the hardness reaches above HV2000, and the friction coefficient is less than 0.2.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is to provide a method for preparing a wear-resistant lubricating film layer of aviation shaft parts. The steps include: a. Finish the surface of aviation shaft parts; b. Clean the oil stains on the surface of parts; c. Determine the area where the diamond-like carbon film needs to be prepared, and use protective tooling to shield the surface of the parts that do not need to deposit the film; d. Fix the parts in the vacuum coating chamber, with the area to be coated facing the magnetron sputtering target, connect the landing gear to the negative pole of the bias power supply, and connect the vacuum coating chamber to the positive pole of the power supply; e. Turn on the argon plasma cleaning source and perform argon plasma etching cleaning on the landing gear surface for a cleaning time of not less than 0.5 h; f. Preparing a metal adhesion layer of NiCr, Cr, and W on the landing gear surface using magnetron sputtering; g. Preparing a diamond-like carbon film layer on the metal adhesion layer using a plasma enhanced chemical vapor deposition method; h. Remove the protective tooling on the surface of the parts and conduct a quality inspection on the film layer.

[0007] According to the method for preparing a wear-resistant lubricating film layer for aviation shaft parts described in the present invention, a further preferred technical solution is: before step a, check the surface condition of the parts, and then perform finishing after there are no bumps or scratches.

[0008] According to the method for preparing a wear-resistant lubricating film layer for aviation shaft parts described in the present invention, a further preferred technical solution is: in step a, finishing must make the surface roughness of the part less than Ra0.2μm.

[0009] According to the method for preparing a wear-resistant lubricating film layer for aviation shaft parts described in the present invention, a further preferred technical scheme is: in step b, use anhydrous ethanol and acetone to ultrasonically clean the parts, and there is no trace of rust after cleaning. After the parts are moistened with deionized water, check whether the water film is continuous for 30 seconds, and it is qualified if there is no water film rupture. After passing the inspection, blow dry in time, check whether the parts are rust-free, and if unqualified, perform the cleaning process again.

[0010] According to the method for preparing a wear-resistant lubricating film layer for aviation shaft parts described in the present invention, a further preferred technical solution is: in step f, by controlling the sputtering power of NiCr, Cr, and W, the prepared metal adhesion layer has the organizational structure of NiCr, NiCr / Cr mixed layer, and Cr / W mixed layer; in step g, by controlling the sputtering power and gas flow of W, the prepared diamond-like film layer has the organizational structure of W / C mixed layer and diamond-like functional layer.

[0011] According to the method for preparing a wear-resistant lubricating film layer of an aviation shaft part of the present invention, a further preferred technical solution is: in step f, the specific operation is: first, turn on the NiCr target sputtering power supply, the current is 40~70A / m 2 , deposit NiCr layer, bias voltage -50V~-200V; turn on Cr target sputtering power, Cr target current 120~170A / m 2 , forming a mixed layer of NiCr / Cr; turn off the NiCr target, turn on the W target sputtering power supply, and the W target current is 100~130 A / m 2 , forming a Cr / W mixed layer.

[0012] According to the method for preparing a wear-resistant lubricating film layer for aviation shaft parts described in the present invention, its further preferred technical solution is: in step g, the specific operation is: turn off the Cr target, introduce a carbon-containing gas source, and gradually increase the flow rate to 500sccm; gradually reduce the W target power until it is turned off, and gradually increase the bias voltage to -500V~-700V, and prepare the DLC functional layer by plasma enhanced chemical vapor deposition.

[0013] According to the method for preparing a wear-resistant lubricating film layer for aviation shaft parts described in the present invention, a further preferred technical solution is: in step g, the carbon-containing gas source is one or a mixed gas of any of methane, ethane, ethylene or acetylene.

[0014] According to the method for preparing a wear-resistant lubricating film layer for aviation shaft parts described in the present invention, a further preferred technical solution is that the thickness of the diamond-like carbon film layer is not less than 2 microns.

[0015] According to the method for preparing a wear-resistant lubricating film layer for aviation shaft parts described in the present invention, a further preferred technical solution is: the protective tooling adopts aluminum foil, protective tape to achieve shielding or a special protective device to achieve shielding.

[0016] Compared with the prior art, the technical solution of the present invention has the following advantages / benefits: 1. By controlling the combination of magnetron sputtering and plasma enhanced chemical vapor deposition, the wear-resistant lubricating film layer prepared has a uniform and dense structure, good bonding with the substrate, low process temperature, and excellent wear resistance and friction reduction performance. The process is highly controllable, the total thickness of the film layer is 3μm to 6μm, the hardness reaches above HV2000, and the friction coefficient is less than 0.2.

[0017] 2. The film structure has a gradient transition film structure of NiCr / NiCr-Cr / Cr-W / WC / DLC, increasing the number of gradient layers in the transition layer to relieve interface stress. The sputtering current gradient is regulated to achieve a gradual transition between transition layers, increase the interface bonding force, and make the indentation bonding force of the DLC film reach level 1, so that the film is not easy to peel off during service.

[0018] 3. The process temperature used in the present invention is lower than 2000°C, which will not have an adverse effect on the tensile properties and fatigue properties of the substrate.

[0019] 4. After the processing of the present invention is completed, the film layer is dense and does not require additional sealing steps to meet the sealing requirements.

[0020] 5. The total thickness of the film layer is 3μm~6μm, which has no effect on the dimensional accuracy of the parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 The present invention is a flow chart of a method for preparing a wear-resistant lubricating film layer for aviation shaft parts.

[0023] Figure 2 These are the microscopic morphologies of electroplated hard chrome and DLC film layers, where a) and c) are electroplated hard chrome, and b) and d) are DLC film layers.

[0024] Figure 3 It is a film layer structure diagram of a method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. Therefore, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, it may not be further defined or explained in the subsequent drawings.

[0027] Embodiment 1: like Figure 1 As shown, a method for preparing a wear-resistant lubricating film layer for aviation shaft parts. The steps include: a. Finish the surface of aviation shaft parts. The surface roughness of the parts must be less than Ra0.2μm. b. Clean the oil stains on the surface of the parts, use anhydrous ethanol and acetone to ultrasonically clean the parts. After cleaning, there should be no traces of rust. After wetting the parts with deionized water, check that the water film is continuous for 30 seconds. If there is no water film rupture, it is qualified. After passing the inspection, blow dry in time and check that the parts are free of rust. If unqualified, perform the cleaning process again until the standard is met; c. Determine the area where the diamond-like carbon film layer needs to be prepared, and use protective tools to shield the surface of the parts that do not need to deposit the film layer. Protective tools are a general term with various forms. For example, protective tools can be used to shield by aluminum foil, protective tape, or special protective devices; d. Fix the parts in the vacuum coating chamber, with the area to be coated facing the magnetron sputtering target, connect the landing gear to the negative pole of the bias power supply, and connect the vacuum coating chamber to the positive pole of the power supply; e. Turn on the argon plasma cleaning source and perform argon plasma etching cleaning on the landing gear surface. The cleaning time is not less than 0.5 hours. Of course, the cleaning time can be flexibly set according to needs and can also be less than 0.5 hours; f. Preparing a metal adhesion layer of NiCr, Cr, and W on the landing gear surface using magnetron sputtering; g. Preparing a diamond-like carbon film layer on the metal adhesion layer using a plasma enhanced chemical vapor deposition method; h. After reaching the preset film thickness, turn off the anode layer ion source and bias power supply. After the temperature in the chamber drops below 80°C, open the furnace door, take out the landing gear, remove the protective tooling on the surface of the parts, and conduct a qualification test on the film layer. The thickness of the diamond-like carbon film layer is required to be no less than 2 microns.

[0028] At the same time, before step a, it is necessary to check the surface condition of the parts and confirm that there are no bumps or scratches before finishing.

[0029] In step f, by controlling the sputtering power of NiCr, Cr, and W, the prepared metal adhesion layer has the organizational structure of NiCr, NiCr / Cr mixed layer, and Cr / W mixed layer. The specific operation is: first, turn on the NiCr target sputtering power, the current is 40~70A / m2, and the NiCr layer is deposited with a bias voltage of -50V~-200V; turn on the Cr target sputtering power, the Cr target current is 120~170A / m2, and a NiCr / Cr mixed layer is formed; turn off the NiCr target, turn on the W target sputtering power, the W target current is 100~130A / m2, and the NiCr / Cr mixed layer is formed; m2, forming a Cr / W mixed layer; in step g, by controlling the sputtering power and gas flow of W, the prepared diamond-like film layer has the organizational structure of W / C mixed layer and DLC functional layer (diamond-like functional layer), and the specific operation is: turn off the Cr target, introduce a carbon-containing gas source, and gradually increase the flow rate to 500sccm; gradually reduce the W target power until it is turned off, gradually increase the bias voltage to -500V~-700V, and prepare the DLC functional layer by plasma enhanced chemical vapor deposition. In step g, the carbon-containing gas source introduced is one or a mixture of any of methane, ethane, ethylene or acetylene, and of course other gases that can play the same role can also be used. Figure 2 This is a comparison between the hard chrome layer with a large number of microcracks and the DLC film layer.

[0030] Embodiment 2: Based on Example 1, the coating parameters are further illustrated in detail. In step f, the NiCr target sputtering power supply is first turned on, with a current of 60 A / m 2 , deposit NiCr layer, deposition time 40min, bias voltage -100V; turn on Cr target sputtering power, Cr target current 140 A / m 2 , forming a mixed layer of NiCr / Cr, the deposition time is 50min; turn off the NiCr target, turn on the W target sputtering power supply, the W target current is 110 A / m 2 , forming a Cr / W mixed layer, the deposition time is 30min.

[0031] In step g, acetylene gas is introduced, and the flow rate is gradually increased from 50 sccm to 200 sccm, the Cr target is turned off, and the W target current is gradually reduced to zero to form a W / C mixed layer for 30 minutes; the W target is turned off, the acetylene is increased from 200 sccm to 600 sccm, and the bias voltage is increased from -100 V to -600 V, and the DLC functional layer is prepared by plasma enhanced chemical vapor deposition for 500 minutes.

[0032] Working principle: Use magnetron sputtering and discharge plasma enhanced chemical vapor deposition method. Magnetron sputtering refers to the use of glow plasma discharge to ionize argon gas to produce argon ions, while applying a negative bias to the target material (NiCr, Cr, W target material). Under the constraint of the equipment's magnetic field, argon ions are accelerated in the electric field and continuously sputter the target material, sputtering target atoms out of the target surface. Some target atoms collide with argon ions and are ionized. The target atoms and ions reach the workpiece surface through the combined action of thermal motion and the negative bias applied to the part. By controlling the power of the target power supply, the thickness of the metal adhesion layer is controlled, and the metal adhesion layer is deposited. Plasma enhanced chemical vapor deposition refers to applying a high negative bias to the part to cause acetylene to glow discharge on the surface of the part. Acetylene is ionized into C-containing ions, which are deposited as a DLC functional layer on the surface of the part. The final film structure is as follows: Figure 3 shown.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a wear-resistant lubricating film layer for aviation shaft parts, characterized in that: The steps include: a. Finish the surface of aviation shaft parts; b. Clean the oil stains on the surface of parts; c. Determine the area where the diamond-like carbon film needs to be prepared, and use protective tooling to shield the surface of the parts that do not need to deposit the film; d. Fix the parts in the vacuum coating chamber, with the area to be coated facing the magnetron sputtering target, connect the landing gear to the negative pole of the bias power supply, and connect the vacuum coating chamber to the positive pole of the power supply; e. Turn on the argon plasma cleaning source and perform argon plasma etching cleaning on the landing gear surface for a cleaning time of not less than 0.5 h; f. Preparing a metal adhesion layer of NiCr, Cr, and W on the landing gear surface using magnetron sputtering; g. Preparing a DLC functional layer on the metal adhesion layer using a plasma enhanced chemical vapor deposition method; h. Remove the protective tooling on the surface of the parts and conduct a quality inspection on the film layer.

2. The method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to claim 1, characterized in that: Before step a, check the surface condition of the parts and make sure there are no bumps or scratches before finishing.

3. The method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to claim 1, characterized in that: In step a, finishing must make the surface roughness of the part less than Ra0.2μm.

4. The method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to claim 1, characterized in that: In step b, use anhydrous ethanol and acetone to ultrasonically clean the parts. After cleaning, there is no sign of rust. After wetting the parts with deionized water, check whether the water film is continuous for 30 seconds. If there is no water film rupture, it is qualified. After passing the inspection, blow dry in time and check whether the parts are rust-free. If unqualified, perform the cleaning process again.

5. The method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to claim 1, characterized in that: In step f, by controlling the sputtering power of NiCr, Cr, and W, the prepared metal adhesion layer has the organizational structure of NiCr, NiCr / Cr mixed layer, and Cr / W mixed layer; in step g, by controlling the sputtering power and gas flow of W, the prepared diamond-like film layer has the organizational structure of W / C mixed layer and diamond-like functional layer.

6. A method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to any one of claims 1 to 6, characterized in that: In step f, the specific operation is as follows: first, turn on the NiCr target sputtering power supply, the current is 40~70A / m 2 , deposit NiCr layer, bias voltage -50V~-200V; turn on Cr target sputtering power, Cr target current 120~170A / m 2 , forming a mixed layer of NiCr / Cr; turn off the NiCr target, turn on the W target sputtering power supply, and the W target current is 100~130 A / m 2 , forming a Cr / W mixed layer.

7. A method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to any one of claims 1 to 6, characterized in that: In step g, the specific operation is: turn off the Cr target, introduce a carbon-containing gas source, and gradually increase the flow rate to 500 sccm; gradually reduce the W target power until it is turned off, and gradually increase the bias voltage to -500V~-700V to prepare the DLC functional layer by plasma enhanced chemical vapor deposition.

8. The method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to claim 7, characterized in that: In step g, the carbon-containing gas source introduced is one or a mixture of any of methane, ethane, ethylene or acetylene.

9. The method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to claim 7, characterized in that: The thickness of the DLC functional layer is not less than 2 microns.

10. The method for preparing a wear-resistant lubricating film layer for aviation shaft parts according to claim 1, characterized in that: The protective tooling adopts aluminum foil, protective tape to achieve shielding or a special protective device to achieve shielding.

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