Titanium alloy surface wide-temperature-range self-lubricating coating and preparation method thereof

Abstract

The invention provides a titanium alloy surface wide-temperature-range self-lubricating coating and a preparation method thereof.The preparation method comprises the steps that a ceramic coating is prepared on the titanium alloy surface through a micro-arc oxidation technology; the surface of the ceramic coating is coated with an organic coating in a blade coating mode through a blade coating device, and the step of coating the surface of the ceramic coating with the organic coating in a blade coating mode through the blade coating device comprises the following steps that the surface of the ceramic coating is coated with emulsion in a blade coating mode, the emulsion is deionized water and acrylic acid, and the volume fraction of the acrylic acid is 20%-80%; and the titanium alloy subjected to blade coating is cured and cooled, and the wide-temperature-range self-lubricating coating on the surface of the titanium alloy is obtained. The titanium alloy surface wide-temperature-range self-lubricating coating prepared by the preparation method provided by the invention has a self-lubricating effect and also shows excellent wear-resisting and friction-reducing characteristics.

Description

Technical Field

[0001] The invention relates to the technical field of coating preparation, and specifically provides a wide-temperature-range self-lubricating coating on a titanium alloy surface and a preparation method thereof. Background Art

[0002] Titanium and titanium alloys have excellent properties such as low density, high specific strength, corrosion resistance and good biocompatibility, and are widely used in aerospace, automotive, electronics, chemical and medical fields. However, the wear resistance of titanium and titanium alloys is poor, which limits their application to a certain extent. At present, the main methods to improve the wear resistance of titanium and titanium alloys are alloying and applying protective coatings. Among them, coatings prepared by magnetron sputtering, plasma spraying and surface nitriding can effectively improve the friction and wear properties of titanium and titanium alloys. Magnetron sputtering technology mainly uses a magnetic field to add charged particles to the surface of titanium alloys, thereby generating a surface with special properties, thereby improving the wear resistance of titanium alloys; plasma spraying technology refers to a method of using a plasma arc driven by direct current as a heat source to heat ceramics, alloys or metals to a molten or semi-molten state, and spraying them at high speed to the surface of titanium alloys to form a firmly attached surface layer. The generated surface layer has excellent wear resistance and corrosion resistance. Surface nitriding technology is a chemical heat treatment method that infiltrates nitrogen atoms into the surface of titanium alloys to form a nitride modified layer. Due to the high hardness of nitrides, the surface of titanium alloys has good wear resistance. Micro-arc oxidation technology is a technology developed on the basis of anodizing. Its working principle relies on the matching and adjustment of electrolyte and electrical parameters. Under the instantaneous high temperature and high pressure generated by arc discharge, a modified ceramic coating mainly composed of matrix metal oxides and supplemented by electrolyte components grows on the surface of metals such as aluminum, magnesium, titanium and their alloys. The thickness of the coating is relatively thick, up to hundreds of microns, and its anti-corrosion and wear-resistant properties are often better than those of traditional anodized coatings. However, although the ceramic coating generated by micro-arc oxidation technology shows excellent performance in terms of anti-corrosion and wear resistance, it performs poorly in terms of friction reduction performance, and often requires the addition of other technologies to improve its friction reduction effect. In addition, there are a large number of micropores and microcracks on the surface of the ceramic coating generated by micro-arc oxidation technology, which provides adhesion space for the scraping of the organic coating, greatly improving the bonding strength between the organic coating and the substrate, and solving the problem of the organic coating being easy to fall off.

[0003] Therefore, how to combine micro-arc oxidation technology with scraping technology to prepare a wear-resistant and friction-reducing coating with self-lubricating effect has become an urgent problem to be solved. Summary of the invention

[0004] In view of this, the present invention provides a wide temperature range self-lubricating coating on the surface of a titanium alloy and a preparation method thereof, so as to solve the problems of poor self-lubricating effect, poor wear resistance, high friction coefficient, etc. of the titanium alloy.

[0005] In one aspect, the present invention provides a method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface, comprising:

[0006] A ceramic coating was prepared on the surface of titanium alloy using micro-arc oxidation technology;

[0007] A layer of organic coating is applied on the surface of the ceramic coating by using a coating device, wherein the layer of organic coating is applied on the surface of the ceramic coating by using a coating device, comprising the following steps:

[0008] Applying an emulsion on the surface of the ceramic coating, wherein the emulsion is deionized water + acrylic acid, and the volume fraction of acrylic acid is 20%-80%;

[0009] The titanium alloy after scraping is solidified and cooled to obtain a self-lubricating coating with a wide temperature range on the surface of the titanium alloy.

[0010] Preferably, preparing a ceramic coating on the surface of a titanium alloy using micro-arc oxidation technology comprises:

[0011] Grinding the titanium alloy surface to remove rust and make the titanium alloy surface smooth;

[0012] The polished titanium alloy is cleaned, and then placed in an electrolyte for micro-arc oxidation treatment to obtain a ceramic coating, wherein the micro-arc oxidation treatment adopts a bidirectional pulsed AC voltage, with a forward voltage of 300-420V, a negative voltage of 60-160V, a pulse frequency of 100-1000Hz, a duty cycle of 10-50%, and an oxidation time of 10-50min.

[0013] More preferably, the electrolyte composition is as follows: Na 2 SiO 3 9H 2 O: 20-40 g / l, (NaPO 3 ) 6 :5-15g / l,Na 2 MoO 4 : 2-6g / l, KOH: 2-6g / l.

[0014] Further preferably, before applying the organic coating, the ceramic coating on the surface of the titanium alloy is cleaned.

[0015] More preferably, the curing treatment is carried out in a drying oven at a temperature of 40° C. to 80° C. for 20 to 40 minutes.

[0016] More preferably, the thickness of the ceramic coating is 5.9-36.1 μm, and the thickness of the organic coating is 5.6-150.6 μm.

[0017] The present invention also provides a wide temperature range self-lubricating coating on the surface of a titanium alloy, which is prepared by using the above-mentioned method for preparing the wide temperature range self-lubricating coating on the surface of a titanium alloy.

[0018] Preferably, at room temperature and 300° C., the friction coefficient curve of the wide temperature range self-lubricating coating on the titanium alloy surface is smooth, and the friction coefficient is 0.06-0.19.

[0019] The present invention provides a method for preparing a wide-temperature-range self-lubricating coating on a titanium alloy surface. The method comprises the following steps: first preparing a layer of micro-arc oxidation ceramic coating (wear-resistant coating) on ​​the titanium alloy surface, and then scraping a layer of organic coating (friction-reducing coating) on ​​the surface of the micro-arc oxidation ceramic coating. The preparation of the micro-arc oxidation ceramic coating can greatly improve the wear resistance and corrosion resistance of the titanium alloy surface, and at the same time provide a focus space for scraping the organic coating, which is beneficial to improving the bonding strength of the organic coating and making the organic coating less likely to crack and fall off, thereby ensuring the lubrication effect of the titanium alloy surface. The scraping of the organic coating can enhance the self-lubricating effect of the titanium alloy surface and reduce the wear phenomenon occurring during the running-in stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a friction coefficient curve diagram of the self-lubricating coatings prepared in Examples 1, 3-5 and Comparative Examples 1 and 3 at room temperature;

[0021] Figure 2 It is a friction coefficient curve of the self-lubricating coatings prepared in Examples 2 and 6 and Comparative Examples 2 and 4 at a high temperature of 300°C;

[0022] Figure 3 is the XRD spectrum of the self-lubricating coatings prepared in Examples 1, 4, 5, and 6;

[0023] Figure 4 1 is a macroscopic photograph of the self-lubricating coating obtained in Example 1, wherein (a) is a macroscopic photograph of the ceramic coating, (b) is a macroscopic photograph of the organic coating, and (c) is a macroscopic photograph of the organic coating after friction at room temperature;

[0024] Figure 5 These are macroscopic photographs of the self-lubricating coating obtained in Example 2, in which (a) is a macroscopic photograph of the ceramic coating, (b) is a macroscopic photograph of the organic coating, and (c) is a macroscopic photograph of the organic coating after high-temperature friction at 300°C. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific embodiments.

[0026] The present invention provides a method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface, comprising:

[0027] A ceramic coating was prepared on the surface of titanium alloy using micro-arc oxidation technology;

[0028] A layer of organic coating is applied on the surface of the ceramic coating by using a coating device, wherein the layer of organic coating is applied on the surface of the ceramic coating by using a coating device, comprising the following steps:

[0029] Applying an emulsion on the surface of the ceramic coating, wherein the emulsion is deionized water + acrylic acid, and the volume fraction of acrylic acid is 20%-80%;

[0030] The titanium alloy after scraping is solidified and cooled to obtain a self-lubricating coating with a wide temperature range on the surface of the titanium alloy.

[0031] The method for preparing a wide-temperature-range self-lubricating coating on the surface of a titanium alloy comprises the following steps: first preparing a layer of micro-arc oxidation ceramic coating (wear-resistant coating) on ​​the surface of the titanium alloy, and then scraping a layer of organic coating (friction-reducing coating) on ​​the surface of the micro-arc oxidation ceramic coating. The preparation of the micro-arc oxidation ceramic coating can greatly improve the wear resistance and corrosion resistance of the titanium alloy surface, and at the same time provide a focus space for scraping the organic coating, which is beneficial to improving the bonding strength of the organic coating, making the organic coating less likely to crack and fall off, so as to ensure the lubrication effect of the titanium alloy surface. The scraping of the organic coating can enhance the self-lubricating effect of the titanium alloy surface, and at the same time reduce the wear phenomenon occurring during the running-in stage.

[0032] Preferably, preparing a ceramic coating on the surface of a titanium alloy using micro-arc oxidation technology comprises:

[0033] Grinding the titanium alloy surface to remove rust and make the titanium alloy surface smooth;

[0034] The polished titanium alloy is cleaned, and then the cleaned titanium alloy is placed in an electrolyte for micro-arc oxidation treatment to obtain a ceramic coating, wherein the micro-arc oxidation treatment adopts a bidirectional pulsed AC voltage, the forward voltage is 300-420V, the negative voltage is 60-160V, the pulse frequency is 100-1000Hz, the duty cycle is 10-50%, and the oxidation time is 10-50min. Cleaning can be performed by alcohol ultrasonic cleaning.

[0035] Rust removal is used to remove surface defects of titanium alloy and thoroughly clean its surface, which is beneficial to improving the flatness and molding quality of subsequent ceramic coating.

[0036] More preferably, the electrolyte composition is as follows: Na 2 SiO 3 9H 2 O: 20-40 g / l, (NaPO 3 ) 6 :5-15g / l,Na 2MoO 4 : 2-6g / l, KOH: 2-6g / l.

[0037] It is further preferred that the ceramic coating on the surface of the titanium alloy is cleaned before the organic coating is applied to improve the cleanliness of the surface of the titanium alloy ceramic coating, which is beneficial to improving the molding quality of the subsequent surface coating technology used to scrape a layer of organic coating on the surface of the titanium alloy ceramic coating. Preferably, the titanium alloy ceramic coating is ultrasonically cleaned by a cleaning solvent. Ultrasonic cleaning has a better cleaning effect than other cleaning methods. It mainly uses cleaning solvent and water as the medium, and relies on the oscillation generated by ultrasound in the liquid to remove dirt to achieve the cleaning purpose, which is beneficial to achieve a thorough cleaning of the surface of the titanium alloy ceramic coating to improve the molding quality of the subsequent organic coating.

[0038] More preferably, the curing treatment is carried out in a drying oven at a temperature of 40° C. to 80° C. for 20 to 40 minutes.

[0039] Among them, the curing temperature is the volatilization temperature of water molecules inside the coating and the curing temperature of polymers inside the coating. The influence rule is related to the curing temperature. When the temperature is low, the water molecules evaporate slowly during the curing process, causing bubbles to appear in the coating, which will affect the bonding strength and hardness. If the temperature is higher, it will exceed the standard reaction temperature, causing the polymers in the coating to volatilize during the curing stage, affecting its self-lubricating properties. Therefore, a curing temperature of 40°C-80°C is the optimal curing temperature.

[0040] In addition, the cooling process can be directly cooled from the curing temperature to room temperature. The cooling process is conducive to closely combining the organic coating and the ceramic coating together to form an integrated coating with both friction reduction and wear resistance properties.

[0041] Considering that the installation gap of some specific parts is small, the organic coating can show high lubrication performance at about 5μm. However, since the organic coating is relatively soft, as the coating thickness increases, although the lubrication effect can be guaranteed, its wear resistance gradually decreases. Therefore, the thickness of the ceramic coating is controlled to be 5.9-36.1μm, and the thickness of the organic coating is controlled to be 5.6-150.6μm.

[0042] The present invention also provides a wide temperature range self-lubricating coating on the surface of a titanium alloy, which is prepared by using the above-mentioned method for preparing the wide temperature range self-lubricating coating on the surface of a titanium alloy.

[0043] Preferably, the wide temperature range self-lubricating coating on the titanium alloy surface has a smooth friction coefficient curve at room temperature and 300° C., and the friction coefficient is 0.06-0.19.

[0044] Example 1

[0045] A method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface, the specific steps are as follows:

[0046] (1) Preparation of ceramic coating, the process flow is as follows:

[0047] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0048] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0049] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0050] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0051] 5) Prepare electrolyte: Sodium silicate nonahydrate 2 SiO 3 9H 2 O (30g / l), sodium hexametaphosphate (NaPO 3 ) 6 (10g / l), sodium molybdate Na 2 MoO 4 (2g / l) and potassium hydroxide KOH (2g / l) are used as electrolytes to prepare an electrolyte solution, which is placed in an electrolytic cell for standby use;

[0052] 6) Micro-arc oxidation: Place the polished substrate in the prepared electrolyte, connect the substrate to the positive pole of the power supply, and connect the electrolytic cell to the negative pole of the power supply; adjust the oxidation power supply parameters to 340V positive voltage, 160V negative voltage, 1000Hz frequency, 50% duty cycle, and 40min oxidation time. After checking that everything is correct, start oxidation;

[0053] 7) Weighing and measuring after cleaning: After rinsing the oxidized substrate with deionized water, place it in alcohol for ultrasonic cleaning for 5 minutes, weigh it with an analytical balance, select five different points to measure the sample thickness and film thickness with a screw micrometer and eddy current thickness gauge, and take the average value, and place the sample for later use;

[0054] 8) The thickness of the ceramic coating is 36.146 μm, the weight gain is 0.1557 g, and the unit weight gain is 46.259 g·cm -2 ;

[0055] (2) Preparation of organic coating, the process flow is as follows:

[0056] 1) Scraping: Place the substrate after forming the ceramic coating in a scraper, adjust the machine parameters: scraping rounds are 20, the volume fraction of acrylic acid is 50%, and scraping is performed;

[0057] 2) Drying: Place the coated substrate in a drying oven and dry at 80°C for 30 minutes;

[0058] 3) Repeat 1) and 2) three times;

[0059] 4) Measurement and weighing: Select five different points of the sample and measure the sample thickness with a screw micrometer to obtain the average value and weigh it, and then place the sample aside for later use;

[0060] 5) The thickness of the organic coating is 37.8 μm, the weight gain is 0.0864 g, and the unit weight gain is 25.66973 g·cm -2 ;

[0061] (3) Friction and wear test:

[0062] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at room temperature, load of 15N, and speed of 150r / min;

[0063] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0064] Example 2

[0065] A method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface, the specific steps are as follows:

[0066] (1) Preparation of ceramic coating, the process flow is as follows:

[0067] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0068] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0069] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0070] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0071] 5) Prepare electrolyte: Sodium silicate nonahydrate 2 SiO 3 9H 2 O (20g / l), sodium hexametaphosphate (NaPO 3) 6 (5g / l), sodium molybdate Na 2 MoO 4 (6g / l) and potassium hydroxide KOH (6g / l) are used as electrolytes to prepare an electrolyte solution, which is placed in an electrolytic cell for standby use;

[0072] 6) Micro-arc oxidation: Place the polished substrate in the prepared electrolyte, connect the substrate to the positive pole of the power supply, and connect the electrolytic cell to the negative pole of the power supply; adjust the oxidation power supply parameters to 420V positive voltage, 60V negative voltage, 800Hz frequency, 20% duty cycle, and 10min oxidation time. Start oxidation after checking that everything is correct;

[0073] 7) Weighing and measuring after cleaning: After rinsing the oxidized substrate with deionized water, place it in alcohol for ultrasonic cleaning for 5 minutes, weigh it with an analytical balance, select five different points to measure the sample thickness and film thickness with a screw micrometer and eddy current thickness gauge, and take the average value, and place the sample for later use;

[0074] 8) The thickness of the ceramic coating is 8.098 μm, the weight gain is 0.0668 g, and the unit weight gain is 18.68243 g·cm -2 ;

[0075] (2) Preparation of organic coating, the process flow is as follows:

[0076] 1) Scraping: Place the substrate after forming the ceramic coating in a scraper, adjust the machine parameters: scraping rounds are 30, the volume fraction of acrylic acid is 20%, and scraping is performed;

[0077] 2) Drying: Place the coated substrate in a drying oven and dry at 60°C for 40 minutes;

[0078] 3) Measurement and weighing: Select five different points of the sample and use a screw micrometer to measure the sample thickness, take the average value and weigh it, and place the sample aside for later use:

[0079] 5) The thickness of the organic coating is 11.4 μm, the weight gain is 0.0132 g, and the unit weight gain is 3.691738 g·cm -2 ;

[0080] (3) Friction and wear test:

[0081] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at a high temperature of 300℃, a load of 15N, and a speed of 150r / min;

[0082] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0083] Example 3

[0084] A method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface, the specific steps are as follows:

[0085] (1) Preparation of ceramic coating, the process flow is as follows:

[0086] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0087] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0088] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0089] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0090] 5) Prepare electrolyte: Sodium silicate nonahydrate 2 SiO 3 9H 2 O (40g / l), sodium hexametaphosphate (NaPO 3 ) 6 (15g / l), sodium molybdate Na 2 MoO 4 (4g / l) and potassium hydroxide KOH (4g / l) are used as electrolytes to prepare an electrolyte solution, which is placed in an electrolytic cell for standby use;

[0091] 6) Micro-arc oxidation: Place the polished substrate in the prepared electrolyte, connect the substrate to the positive pole of the power supply, and connect the electrolytic cell to the negative pole of the power supply; adjust the oxidation power supply parameters to 300V positive voltage, 120V negative voltage, 100Hz frequency, 30% duty cycle, and 50min oxidation time. After checking that everything is correct, start the oxidation;

[0092] 7) Weighing and measuring after cleaning: After rinsing the oxidized substrate with deionized water, place it in alcohol for ultrasonic cleaning for 5 minutes, weigh it with an analytical balance, select five different points to measure the sample thickness and film thickness with a screw micrometer and eddy current thickness gauge, and take the average value, and place the sample for later use;

[0093] 8) The thickness of the generated ceramic coating is 20.064 μm, the weight gain is 0.1114 g, and the unit weight gain is 33.10458 g·cm -2 ;

[0094] (2) Preparation of organic coating, the process flow is as follows:

[0095] 1) Scraping: Place the substrate after forming the ceramic coating in a scraper, adjust the machine parameters: scraping rounds are 10, the volume fraction of acrylic acid is 80%, and scraping is performed;

[0096] 2) Drying: Place the coated substrate in a drying oven and dry at 80°C for 30 minutes

[0097] 3) Repeat 1) and 2) 5 times;

[0098] 4) Measurement and weighing: Select five different points of the sample and measure the sample thickness with a screw micrometer to obtain the average value and weigh it, and then place the sample aside for later use;

[0099] 5) The thickness of the organic coating is 150.6 μm, the weight gain is 0.2418 g, and the unit weight gain is 71.85537 g·cm -2 ;

[0100] (3) Friction and wear test:

[0101] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at room temperature, load of 15N, and speed of 150r / min;

[0102] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0103] Example 4

[0104] A method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface, the specific steps are as follows:

[0105] (1) Preparation of ceramic coating, the process flow is as follows:

[0106] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0107] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0108] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0109] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0110] 5) Prepare electrolyte: Sodium silicate nonahydrate 2 SiO 3 9H 2 O (20g / l), sodium hexametaphosphate (NaPO 3) 6 (5g / l), sodium molybdate Na 2 MoO 4 (6g / l) and potassium hydroxide KOH (6g / l) are used as electrolytes to prepare an electrolyte solution, which is placed in an electrolytic cell for standby use;

[0111] 6) Micro-arc oxidation: Place the polished substrate in the prepared electrolyte, connect the substrate to the positive pole of the power supply, and connect the electrolytic cell to the negative pole of the power supply; adjust the oxidation power supply parameters to 380V positive voltage, 80V negative voltage, 500Hz frequency, 10% duty cycle, and 20min oxidation time. Start oxidation after checking that everything is correct;

[0112] 7) Weighing and measuring after cleaning: After rinsing the oxidized substrate with deionized water, place it in alcohol for ultrasonic cleaning for 5 minutes, weigh it with an analytical balance, select five different points to measure the sample thickness and film thickness with a screw micrometer and eddy current thickness gauge, and take the average value, and place the sample for later use;

[0113] 8) The thickness of the ceramic coating is 5.91 μm, the weight gain is 0.0498 g, and the unit weight gain is 14.18552 g·cm -2 ;

[0114] (2) Preparation of organic coating, the process flow is as follows:

[0115] 1) Scraping: Place the substrate after forming the ceramic coating in a scraper, adjust the machine parameters: scraping rounds are 30, the volume fraction of acrylic acid is 20%, and scraping is performed;

[0116] 2) Drying: Place the coated substrate in a drying oven and dry at 40°C for 50 minutes

[0117] 3) Repeat 1) and 2) 5 times;

[0118] 4) Measurement and weighing: Select five different points of the sample and measure the sample thickness with a screw micrometer to obtain the average value and weigh it, and then place the sample aside for later use;

[0119] 5) The thickness of the organic coating is 36.8 μm, the weight gain is 0.0498 g, and the unit weight gain is 14.18552 g·cm -2 ;

[0120] (3) Friction and wear test:

[0121] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at room temperature, load of 15N, and speed of 150r / min;

[0122] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0123] Example 5

[0124] A method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface, the specific steps are as follows:

[0125] (1) Preparation of ceramic coating, the process flow is as follows:

[0126] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0127] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0128] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0129] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0130] 5) Prepare electrolyte: Sodium silicate nonahydrate 2 SiO 3 9H 2 O (20g / l), sodium hexametaphosphate (NaPO 3 ) 6 (5g / l), sodium molybdate Na 2 MoO 4 (6g / l) and potassium hydroxide KOH (6g / l) are used as electrolytes to prepare an electrolyte solution, which is placed in an electrolytic cell for standby use;

[0131] 6) Micro-arc oxidation: Place the polished substrate in the prepared electrolyte, connect the substrate to the positive pole of the power supply, and connect the electrolytic cell to the negative pole of the power supply; adjust the oxidation power supply parameters to 420V positive voltage, 60V negative voltage, 800Hz frequency, 20% duty cycle, and 10min oxidation time. Start oxidation after checking that everything is correct;

[0132] 7) Weighing and measuring after cleaning: After rinsing the oxidized substrate with deionized water, place it in alcohol for ultrasonic cleaning for 5 minutes, weigh it with an analytical balance, select five different points to measure the sample thickness and film thickness with a screw micrometer and eddy current thickness gauge, and take the average value, and place the sample for later use;

[0133] 8) The thickness of the ceramic coating is 8.098 μm, the weight gain is 0.0668 g, and the unit weight gain is 18.68243 g·cm -2 ;

[0134] (2) Preparation of organic coating, the process flow is as follows:

[0135] 1) Scraping: Place the substrate after forming the ceramic coating in a scraper, adjust the machine parameters: scraping rounds are 30, the volume fraction of acrylic acid is 20%, and scraping is performed;

[0136] 2) Drying: Place the coated substrate in a drying oven and dry at 40°C for 50 minutes

[0137] 3) Measurement and weighing: Select five different points of the sample and use a screw micrometer to measure the sample thickness, take the average value and weigh it, and place the sample aside for later use;

[0138] 4) The thickness of the organic coating is 5.6 μm, the weight gain is 0.0003 g, and the unit weight gain is 0.083903 g·cm -2 ;

[0139] (3) Friction and wear test:

[0140] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at room temperature, load of 15N, and speed of 150r / min;

[0141] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0142] Example 6

[0143] A method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface, the specific steps are as follows:

[0144] (1) Preparation of ceramic coating, the process flow is as follows:

[0145] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0146] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0147] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0148] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0149] 5) Prepare electrolyte: Sodium silicate nonahydrate 2 SiO 3 9H 2 O (40g / l), sodium hexametaphosphate (NaPO 3 ) 6(15g / l), sodium molybdate Na 2 MoO 4 (4g / l) and potassium hydroxide KOH (4g / l) are used as electrolytes to prepare an electrolyte solution, which is placed in an electrolytic cell for standby use;

[0150] 6) Micro-arc oxidation: Place the polished substrate in the prepared electrolyte, connect the substrate to the positive pole of the power supply, and connect the electrolytic cell to the negative pole of the power supply; adjust the oxidation power supply parameters to 300V positive voltage, 120V negative voltage, 100Hz frequency, 30% duty cycle, and 50min oxidation time. After checking that everything is correct, start the oxidation;

[0151] 7) Weighing and measuring after cleaning: After rinsing the oxidized substrate with deionized water, place it in alcohol for ultrasonic cleaning for 5 minutes, weigh it with an analytical balance, select five different points to measure the sample thickness and film thickness with a screw micrometer and eddy current thickness gauge, and take the average value, and place the sample for later use;

[0152] 8) The thickness of the generated ceramic coating is 20.064 μm, the weight gain is 0.1114 g, and the unit weight gain is 33.10458 g·cm -2 ;

[0153] (2) Preparation of organic coating, the process flow is as follows:

[0154] 1) Scraping: Place the substrate after forming the ceramic coating in a scraper, adjust the machine parameters: scraping rounds are 30, the volume fraction of acrylic acid is 80%, and scraping is performed;

[0155] 2) Drying: Place the coated substrate in a drying oven and dry at 80°C for 40 minutes

[0156] 3) Measurement and weighing: Select five different points of the sample and use a screw micrometer to measure the sample thickness, take the average value and weigh it, and place the sample aside for later use;

[0157] 5) The thickness of the organic coating is 9.8 μm, the weight gain is 0.0317 g, and the unit weight gain is 9.420245 g·cm -2 ;

[0158] (3) Friction and wear test:

[0159] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at 300℃, load of 15N, and speed of 150r / min;

[0160] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0161] Comparative Example 1

[0162] The specific steps of TC4's room temperature friction and wear are as follows:

[0163] (1) TC4 pretreatment steps are:

[0164] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0165] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0166] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0167] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0168] (2) Friction and wear test:

[0169] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at room temperature, load of 15N, and speed of 150r / min;

[0170] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0171] Comparative Example 2

[0172] The specific steps of TC4's 300℃ high temperature friction and wear are as follows:

[0173] (1) TC4 pretreatment steps are:

[0174] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0175] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0176] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0177] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0178] (2) Friction and wear test:

[0179] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at 300℃, load of 15N, and speed of 150r / min;

[0180] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0181] Comparative Example 3

[0182] (1) Preparation of ceramic coating, the process flow is as follows:

[0183] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0184] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0185] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0186] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0187] 5) Prepare electrolyte: Sodium silicate nonahydrate 2 SiO 3 9H 2 O (30g / l), sodium hexametaphosphate (NaPO 3 ) 6 (10g / l), sodium molybdate Na 2 MoO 4 (2g / l) and potassium hydroxide KOH (2g / l) are used as electrolytes to prepare an electrolyte solution, which is placed in an electrolytic cell for standby use;

[0188] 6) Micro-arc oxidation: Place the polished substrate in the prepared electrolyte, connect the substrate to the positive pole of the power supply, and connect the electrolytic cell to the negative pole of the power supply; adjust the oxidation power supply parameters to 340V positive voltage, 160V negative voltage, 1000Hz frequency, 50% duty cycle, and 40min oxidation time. After checking that everything is correct, start oxidation;

[0189] 7) Weighing and measuring after cleaning: After rinsing the oxidized substrate with deionized water, place it in alcohol for ultrasonic cleaning for 5 minutes, weigh it with an analytical balance, select five different points to measure the sample thickness and film thickness with a screw micrometer and eddy current thickness gauge, and take the average value, and place the sample for later use;

[0190] 8) The thickness of the generated ceramic coating is 34.532 μm, the weight gain is 0.1665 g, and the unit weight gain is 47.776 g·cm -2 ;

[0191] (2) Friction and wear test:

[0192] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at room temperature, load of 15N, and speed of 150r / min;

[0193] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0194] Comparative Example 4

[0195] (1) Preparation of ceramic coating, the process flow is as follows:

[0196] 1) Parts inspection and drilling: Check whether there are cracks or other defects on the surface of the substrate, make the substrate into a 40×40×2mm square plate and drill holes on the substrate to prepare for subsequent processing;

[0197] 2) Grinding the substrate: Grind the substrate with 180#, 320#, 600#, 800#, 1000# sandpaper;

[0198] 3) Cleaning: Place the polished substrate in alcohol and ultrasonically clean it for 5 minutes to remove surface dirt;

[0199] 4) Weighing: Weigh the substrate using an analytical balance and set aside;

[0200] 5) Prepare electrolyte: Sodium silicate nonahydrate 2 SiO 3 9H 2 O (30g / l), sodium hexametaphosphate (NaPO 3 ) 6 (10g / l), sodium molybdate Na 2 MoO 4 (2g / l) and potassium hydroxide KOH (2g / l) are used as electrolytes to prepare an electrolyte solution, which is placed in an electrolytic cell for standby use;

[0201] 6) Micro-arc oxidation: Place the polished substrate in the prepared electrolyte, connect the substrate to the positive pole of the power supply, and connect the electrolytic cell to the negative pole of the power supply; adjust the oxidation power supply parameters to 340V positive voltage, 160V negative voltage, 1000Hz frequency, 50% duty cycle, and 40min oxidation time. After checking that everything is correct, start oxidation;

[0202] 7) Weighing and measuring after cleaning: After rinsing the oxidized substrate with deionized water, place it in alcohol for ultrasonic cleaning for 5 minutes, weigh it with an analytical balance, select five different points to measure the sample thickness and film thickness with a screw micrometer and eddy current thickness gauge, and take the average value, and place the sample for later use;

[0203] 8) The thickness of the generated ceramic coating is 34.532 μm, the weight gain is 0.1665 g, and the unit weight gain is 47.776 g·cm -2 ;

[0204] (2) Friction and wear test:

[0205] 1) Using ball-disc friction, the friction pair is GCR15 bearing steel ball, and the sample is rubbed for 30 minutes at a high temperature of 300℃, a load of 15N, and a speed of 150r / min;

[0206] 2) Weighing after cleaning: Place the sample in deionized water for 5 minutes under ultrasonication, blow dry with cold air, and then weigh it.

[0207] The wear performance of Examples 1-6 and Comparative Examples 1-4 was evaluated by weight loss method. Figure 1 The friction coefficient curves of the self-lubricating coatings prepared in Examples 1, 3-5 and Comparative Examples 1 and 3 at room temperature are given. Figure 2 The friction coefficient curves of the self-lubricating coatings prepared in Examples 2 and 6 and Comparative Examples 2 and 4 at a high temperature of 300°C are given. Table 1 gives the average friction coefficient and wear data of Examples 1-6 and Comparative Examples 1-4. Figure 1 It can be seen from Table 1 that under normal temperature, the friction curve of the coating prepared by the method proposed by the present invention is smooth, the friction coefficient is 0.06-0.19, which is about 11.5%-36.5% of the substrate, and the wear amount is 0.3-1.0 mg, which is about 0.12%-3.84% of the substrate. However, the friction curves of the coatings prepared by Comparative Examples 1 and 3 are extremely uneven, the average friction coefficient is increased, the friction reduction effect is poor, and the wear weight is large; Figure 2 It can be seen from Table 1 that under high temperature of 300°C, the friction curve of the coating prepared by the present invention is smooth, the friction coefficient is 0.06-0.16, which is about 11.3%-30.2% of the substrate, and the wear amount is 1.2-4.5 mg, which is about 5.4%-20.2% of the substrate, showing excellent wear resistance and friction reduction properties. However, the friction curves of the coatings prepared in Comparative Examples 2 and 4 are extremely uneven, the average friction coefficient is increased, the friction reduction effect is poor, and the wear weight is large.

[0208] Figure 3 The XRD patterns of the self-lubricating coatings prepared in Examples 1, 4, 5 and 6 are given. Figure 3It can be seen that the ceramic coating generated by the electrolyte selected by the present invention has a main crystal phase composition of R-TiO 2 (rutile) and A-TiO 2 (Anatase), which is mainly TiO 2 The stable structure can show higher hardness, so the ceramic coating can show excellent wear resistance.

[0209] Figure 4 The macroscopic photographs of the self-lubricating coating prepared in Example 1 are given, in which (a) is a macroscopic photograph of the ceramic coating, (b) is a macroscopic photograph of the organic coating, and (c) is a macroscopic photograph of the organic coating after friction at room temperature; Figure 4 It can be seen that the surface of the ceramic coating is relatively rough. After adding the organic coating, the surface micropores are filled, the surface is glossy, and the flatness is improved. After the friction and wear test, there are slight wear marks on the surface, indicating that under normal temperature conditions, it has good friction reduction and wear resistance effects.

[0210] Figure 5 The macroscopic photographs of the self-lubricating coating obtained in Example 2 are given. In the figure, (a) is a macroscopic photograph of the ceramic coating, (b) is a macroscopic photograph of the organic coating, and (c) is a macroscopic photograph of the organic coating after high-temperature friction at 300°C. Figure 5 It can be seen that the surface of the ceramic coating is relatively rough. After adding the organic coating, the surface micropores are filled, the surface is glossy, and the flatness is improved. After the friction and wear test, there are slight wear marks on the surface, indicating that under the high temperature condition of 300℃, it has good friction reduction and wear resistance effect.

[0211] The following table is a comparison table of average friction coefficient and wear weight loss of Examples 1-6 and Comparative Examples 1-4.

[0212] Table 1 Average friction coefficient and wear data of Examples 1-6 and Comparative Examples 1-4

[0213] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Average friction coefficient 0.14 0.06 0.13 0.06 0.19 0.16 Wear amount (mg) 0.5 1.2 0.5 0.3 1.0 4.5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Average friction coefficient 0.52 0.53 0.75 0.47 Wear amount (mg) 26 22.3 9.7 4.8 .

Claims

1. A method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface, characterized in that: include: A ceramic coating was prepared on the surface of titanium alloy using micro-arc oxidation technology; A layer of organic coating is applied on the surface of the ceramic coating by using a coating device, wherein the layer of organic coating is applied on the surface of the ceramic coating by using a coating device, comprising the following steps: Applying an emulsion on the surface of the ceramic coating, wherein the emulsion is deionized water + acrylic acid, and the volume fraction of acrylic acid is 20%-80%; The titanium alloy after scraping is solidified and cooled to obtain a self-lubricating coating with a wide temperature range on the surface of the titanium alloy.

2. The method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface according to claim 1, characterized in that: The preparation of a ceramic coating on the surface of titanium alloy using micro-arc oxidation technology includes: Grinding the titanium alloy surface to remove rust and make the titanium alloy surface smooth; The polished titanium alloy is cleaned, and then placed in an electrolyte for micro-arc oxidation treatment to obtain a ceramic coating, wherein the micro-arc oxidation treatment adopts a bidirectional pulsed AC voltage, with a forward voltage of 300-420V, a negative voltage of 60-160V, a pulse frequency of 100-1000Hz, a duty cycle of 10-50%, and an oxidation time of 10-50min.

3. The method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface according to claim 2, characterized in that: The electrolyte composition is as follows: Na2SiO3·9H2O: 20-40 g / l, (NaPO3)6: 5-15 g / l, Na2MoO4: 2-6 g / l, KOH: 2-6 g / l.

4. The method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface according to claim 1, characterized in that: Before applying the organic coating, the ceramic coating on the titanium alloy surface is cleaned.

5. The method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface according to claim 1, characterized in that: The curing conditions are: curing treatment at a temperature of 40°C-80°C in a drying oven for 20-40 minutes.

6. The method for preparing a wide temperature range self-lubricating coating on a titanium alloy surface according to claim 1, characterized in that: The thickness of the ceramic coating is 5.9-36.1 μm, and the thickness of the organic coating is 5.6-150.6 μm.

7. A wide temperature range self-lubricating coating on titanium alloy surface, characterized in that: The titanium alloy surface self-lubricating coating is prepared by the method for preparing a wide temperature range self-lubricating coating on the titanium alloy surface according to any one of claims 1 to 6.

8. The wide temperature range self-lubricating coating on titanium alloy surface according to claim 7, characterized in that: Under the conditions of room temperature and 300° C., the friction coefficient curve of the wide temperature range self-lubricating coating on the titanium alloy surface is smooth, and the friction coefficient is 0.06-0.19.

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