Impact-resistant wear-resistant coating and preparation method thereof

Abstract

The invention belongs to the technical field of wear-resistant coatings, and particularly provides an impact-resistant wear-resistant coating and a preparation method thereof.The impact-resistant wear-resistant coating is prepared from, by weight, 70-90 parts of copper alloy, 10-30 parts of urea formaldehyde microcapsules, 5-10 parts of organic compounds, 0.1-2 parts of silane coupling agents, 60-100 parts of organic solvents, 0.2-2 parts of inhibitors and 0.3-1 part of photocatalysts. The copper alloy and the urea formaldehyde microcapsules are adopted for component design, the impact resistance and abrasion resistance of the coating are enhanced, when cracks appear, the urea formaldehyde microcapsules release a healing agent, self-repairing of the coating is achieved, a formed super-hydrophobic film accelerates self-repairing of the coating, self-cleaning of the coating is achieved, the corrosion resistance of the coating is improved together with the urea formaldehyde microcapsules, and the service life of the coating is prolonged. The problem that in the prior art, a coating is difficult to have the functions of impact resistance, wear resistance, self-repairing, self-cleaning and corrosion resistance at the same time is effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of wear-resistant coatings, and specifically refers to an impact-resistant wear-resistant coating and a preparation method thereof. Background Art

[0002] With the rapid development of industry and science and technology, the preparation of high-performance wear-resistant coatings on the surface of workpieces has received more and more attention. With the continuous advancement of the modernization process, the working conditions of engineering machinery, equipment and components have become increasingly harsh. They have to move and rotate continuously, withstand the impact and wear of different media, and resist corrosion. Therefore, the preparation of high-performance wear-resistant coatings has important practical significance for reducing equipment friction and wear, extending service life, energy conservation and environmental protection, and saving materials.

[0003] The preparation process and coating materials play a key role in the performance of the coating. The coating materials and the preparation process together form a coating with specific properties. At present, the main process for preparing wear-resistant coatings is to directly act on the coating material with high-temperature heat sources such as lasers and flames to plate it on the surface of the metal substrate, and the temperature is difficult to control. Under high temperature, the wear-resistant phase of the coating will inevitably decompose, burn and grow, reducing its wear resistance. The bonding strength between the coating and the substrate is low, and the impact resistance is poor.

[0004] The coating or covering formed by traditional plating technology, although having high hardness, is not impact-resistant, has poor toughness and low impact resistance. Under severe impact and wear, the coating is prone to cracking, wear and peeling. After long-term use, some small cracks will appear and reduce the service life of the coating, and even cause some major losses due to the generation of small cracks. Most traditional plating technologies are complicated to operate, have poor durability, and cannot solve the problem of self-repair and self-cleaning between the coating and the substrate, thereby reducing the service life of the coating. Summary of the invention

[0005] The technical problem to be solved by the present invention is to address the deficiencies in the prior art and provide an impact-resistant and wear-resistant coating and a preparation method thereof. The coating can be tightly bonded to a substrate. Two layers of coating are plated on the surface of the substrate by plasma spraying. Plasma spraying achieves highly uniform distribution of the coating and improves the mechanical strength of the coating. Urea-formaldehyde microcapsules and copper alloys are used to form a first layer of coating. When cracks appear on the coating surface, the urea-formaldehyde microcapsules can release a healing agent to achieve self-repair. The urea-formaldehyde microcapsules can also be used as an adhesive to bond the copper alloy powder together to make the formed coating more dense and uniform. A second coating is plated on the surface of a metal workpiece to form a super-hydrophobic film. The super-hydrophobic film is composed of SiO2 and CeO2. The chemical bonding between the two makes the two tightly bonded, increases the hardness of the coating, improves the toughness of the coating, and by plating the second layer of coating, the substrate surface obtains self-cleaning, self-repairing and corrosion-resistant properties, effectively solving the problem in the prior art that it is difficult for the coating to have both impact resistance, wear resistance, self-repairing, self-cleaning and corrosion-resistant functions at the same time.

[0006] In order to achieve the above technical objectives, the following technical solutions are adopted: The invention proposes an impact-resistant and wear-resistant coating, which comprises a dense coating and a super-hydrophobic film from the inside to the outside, and is composed of the following raw materials in parts by weight: 70-90 parts of copper alloy, 10-30 parts of urea-formaldehyde microcapsules, 5-10 parts of organic compounds, 0.1-2 parts of silane coupling agents, 60-100 parts of organic solvents, 0.2-2 parts of inhibitors and 0.3-1 parts of photocatalysts.

[0007] Preferably, the chemical components of the copper alloy are as follows: Cu 60-90%, Sn 8-30% and Si 2-10% in mass ratio.

[0008] Preferably, the organic compounds are TEOS and PFDS, and the volume ratio of TEOS to PFDS is 2:1.

[0009] Preferably, the silane coupling agent is A151.

[0010] Preferably, the organic solvent is xylene.

[0011] Preferably, the inhibitor is 8-hydroxyquinoline.

[0012] Preferably, the photocatalyst is CeO2.

[0013] Further, the urea-formaldehyde microcapsules are prepared from the following raw materials: urea, formaldehyde, sodium dodecylbenzene sulfonate and a healing agent; Furthermore, the preparation of the urea-formaldehyde microcapsules comprises the following steps: Y1, dissolving urea in formaldehyde to form a formaldehyde solution in a beaker, the dosage ratio of urea to formaldehyde is 1 g:2 mL, after complete dissolution, the pH of the formaldehyde solution is adjusted to 9 with triethanolamine, and the solution is placed in an 80 °C oil bath and stirred for 1 h to obtain a urea-formaldehyde prepolymer; Y2, dissolve sodium dodecylbenzene sulfonate in distilled water to form a solution in a round-bottom flask. After it is completely dissolved, emulsify the solution in a 50 °C oil bath, then add a healing agent, the healing agent is dicyclopentadiene, the mass ratio of the healing agent to sodium dodecylbenzene sulfonate is 1:0.1, and stir continuously for 1 h until an emulsion is formed; Y3, adding the urea-formaldehyde prepolymer obtained in step Y1 to the emulsion obtained in step Y2 and stirring for 25 min, wherein the volume ratio of the urea-formaldehyde prepolymer to the emulsion is 1:6, to form a mixed solution, and maintaining the pH value of the mixed solution at 2.5 by adding 2-3 drops of 1.0 mol / L sulfuric acid; Y4, gradually heating the mixed solution obtained in step Y3 to 70 °C and maintaining the stirring speed at 900 rpm for 4 h to obtain prefabricated microcapsules. In this process, a beaker sealing method is used to reduce heat loss; Y5. Cool the prefabricated microcapsules obtained in step Y4 to room temperature, wash them alternately with deionized water and anhydrous ethanol for three times, and dry the prefabricated microcapsules at 40°C for 18 h to obtain urea-formaldehyde microcapsules.

[0014] The present invention also provides a method for preparing an impact-resistant and wear-resistant coating, which specifically comprises the following steps: S1, putting the copper alloy into a ball mill for grinding to obtain a copper alloy mixed powder of 5-8 μm; S2, cleaning the surface of the metal workpiece substrate. Before using the metal workpiece, grind it with 600#, 1000#, and 1500# emery paper, then ultrasonically rinse it with ethanol and deionized water for 5 minutes respectively to ensure that there is no oil or other impurities on the surface of the metal workpiece, and then dry the metal workpiece with nitrogen gas flow; S3, dissolving 70-90 parts of the ball-milled copper alloy mixed powder, 10-30 parts of urea-formaldehyde microcapsules and 0.1-2 parts of silane coupling agent into 60-100 parts of an organic solvent, and dissolving the mixture using a thermostatic stirrer, wherein the temperature of the thermostatic stirrer is set to 60-80°C, the stirring speed is set to 600-1000 rpm, and the stirring time is 1-2 h; S4, coating the metal workpiece by spraying, pouring the mixture prepared in step S3 into the hopper of the spray gun, spraying it onto the metal workpiece, and then leaving the coating at room temperature overnight for preliminary drying, and then curing the coating in an oven at 80°C for 6 hours, so as to form a dense coating on the surface of the metal workpiece; S5, dissolving 5-10 parts of the organic compound in 90 parts of anhydrous ethanol by ultrasonication to form solution A, adding 0.2-2 parts of the inhibitor and 0.3-1 parts of the photocatalyst to solution A, stirring and heating at 60°C for 90 min to obtain solution B, and stirring solution B continuously at 60°C for 19 h using a condensation reflux device, and then adjusting the pH of solution B to 4 with HAc to obtain a white SiO2 sol, forming a superhydrophobic film; S6, using an immersion extraction speed of 600 mm / min, vertically immerse the metal workpiece coated with a dense coating in step S4 into the white SiO2 sol obtained in step S5, solvothermally heat at 80°C for 8 h, and then anneal the coated metal workpiece at 120°C for 4 h to solidify the coating and remove the unreacted solvent.

[0015] The surface of urea-formaldehyde microcapsules is tightly bonded to the copper alloy powder through physical adsorption, which enhances the mechanical properties of the coating. Urea-formaldehyde microcapsules can chemically react with the active groups on the surfaces of SiO2 and CeO2 to form a more stable bond. In addition, urea-formaldehyde microcapsules can help the filler to be better dispersed in the coating matrix and improve the uniformity of the coating.

[0016] The prepared SiO2 film gives the coating surface good superhydrophobic properties, and the added photocatalyst CeO2 enhances the superhydrophobic properties of the coating. The superhydrophobicity of the SiO2 film and the photocatalytic properties of CeO2 give the coating surface a dual self-cleaning ability. In addition, CeO2 has excellent weather resistance. The superhydrophobic coating prepared in combination with urea-formaldehyde microcapsules and SiO2 is more stable and can better adapt to various environments.

[0017] The beneficial effects achieved by the present invention are as follows: The coating prepared by the invention has a dense structure and strong wear resistance. The low-cost copper alloy is used. The copper alloy provides good electrical conductivity and mechanical strength. The urea-formaldehyde microcapsules and the copper alloy powder are mixed and then plasma-sprayed onto a metal workpiece to plate a dense coating on the surface of the metal workpiece. The plasma spraying realizes a highly uniform distribution of the coating, improves the mechanical strength of the coating, makes the coating tougher, enhances the impact resistance and wear resistance of the coating, and minimizes the waste of the coating, improves the utilization rate of the coating, and improves the plating efficiency. The urea-formaldehyde microcapsules can also be used as an adhesive to bond the copper alloy powder together to form a more dense and uniform coating. The prepared coating material is plated on the surface of a metal substrate. If cracks are generated on the surface of the metal substrate, the microcapsules in the coating will rupture, releasing the healing agent to repair the cracks. In addition, dicyclopentadiene can react with oxides and organic compounds on the surface of the metal substrate to accelerate the self-repair process and restore the overall performance of the coating. In addition, SiO2 in the super-hydrophobic film will also release inhibitors between the skeletons to prevent the generated cracks from further corroding the coating and increase the service life of the coating. The super-hydrophobic film was prepared by the sol-gel method. The preparation process is simple, reduces environmental pollution, and is carried out at low temperature. The prepared super-hydrophobic film also adds a photocatalyst CeO2. On the one hand, through the chemical bonding between CeO2 and SiO2, the two are closely combined, the hardness of the coating is increased, and the toughness of the coating is improved. On the other hand, the self-cleaning effect of the coating surface is enhanced. The water droplets on the super-hydrophobic surface formed by SiO2 can roll off quickly, taking away the dust and pollutants on the surface, thereby keeping the surface clean. CeO2 gives the coating photocatalytic activity, which can effectively degrade the organic pollutants on the surface and enhance the self-cleaning effect. The coating material is plated onto the surface of the metal workpiece. The embedding of urea-formaldehyde microcapsules in the coating material enhances the compactness of the coating and improves the barrier properties of the metal workpiece surface. The coating with urea-formaldehyde microcapsules can effectively block the penetration of corrosive media into the surface of the metal workpiece and delay the occurrence of corrosion. In addition, the physical barrier of the super-hydrophobic surface also effectively delays the invasion of aggressive species. The super-hydrophobic film further prevents the corrosion of the metal workpiece due to the 8-hydroxyquinoline in the SiO2 skeleton. The microcapsule structure helps to improve the chemical stability and durability of the coating. On the other hand, the superhydrophobic coating shows good stability regardless of rain or sunlight exposure, ensuring the long-term effectiveness of the self-cleaning and wear-resistant functions. Based on the above beneficial effects, the impact-resistant and wear-resistant coating prepared by the present invention can be tightly combined with the substrate to form a dense structure, and has the functions of self-repair, self-cleaning and corrosion resistance, which can reduce the number and cost of maintenance and has good economic benefits. In addition, this coating can be widely used in many fields such as construction, automobiles, aviation, medical equipment, etc., to improve the protective performance of the material surface and extend the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a model cross-sectional view and a partially enlarged schematic view of the impact-resistant and wear-resistant coating prepared by the present invention; Figure 2 This is a diagram of the main self-repairing process of the impact-resistant and wear-resistant coating prepared by the present invention when cracks occur; Figure 3 It is a hydrophobic stability diagram of Example 2 and Comparative Examples 1-4 of the impact-resistant and wear-resistant coating prepared by the present invention immersed in a 3.5 wt% NaCl solution. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1: This example proposes an impact-resistant and wear-resistant coating, which is composed of the following raw materials in parts by weight: 70 parts of copper alloy, 30 parts of urea-formaldehyde microcapsules, 5 parts of organic compounds, 0.1 parts of silane coupling agents, 60 parts of organic solvents, 0.2 parts of inhibitors and 0.3 parts of photocatalysts.

[0021] Urea-formaldehyde microcapsules are prepared from the following raw materials: urea, formaldehyde, sodium dodecylbenzene sulfonate and healing agent; The preparation method of urea-formaldehyde microcapsules comprises the following steps: Y1, dissolving urea in formaldehyde in a beaker to form a solution, the amount ratio of urea to formaldehyde is 1 g:2 mL, after complete dissolution, the pH value of the solution is adjusted to 9 with triethanolamine, and the solution is placed in an 80 °C oil bath and stirred for 1 h to obtain a urea-formaldehyde prepolymer; Y2, dissolve sodium dodecylbenzene sulfonate in distilled water to form a solution in a round-bottom flask. After it is completely dissolved, emulsify the solution in a 50 °C oil bath, then add a healing agent, the healing agent is dicyclopentadiene, the mass ratio of the healing agent to sodium dodecylbenzene sulfonate is 1:0.1, and stir continuously for 1 h until an emulsion is formed; Y3, adding the urea-formaldehyde prepolymer obtained in step Y1 to the emulsion obtained in step Y2 and stirring for 25 min, wherein the volume ratio of the urea-formaldehyde prepolymer to the emulsion is 1:6, to form a mixed solution, and maintaining the pH value of the mixed solution at 2.5 by adding 2-3 drops of 1.0 mol / L sulfuric acid; Y4, gradually heating the mixed solution obtained in step Y3 to 70 °C and maintaining the stirring speed at 900 rpm for 4 h to obtain prefabricated microcapsules. In this process, a beaker sealing method is used to reduce heat loss; Y5. Cool the prefabricated microcapsules obtained in step Y4 to room temperature, wash them alternately with deionized water and anhydrous ethanol for three times, and dry the prefabricated microcapsules at 40°C for 18 h to obtain urea-formaldehyde microcapsules.

[0022] This embodiment also provides a method for preparing an impact-resistant and wear-resistant coating, and the preparation method specifically comprises the following steps: S1, putting the copper alloy into a ball mill for grinding to obtain a copper alloy mixed powder of 5-8 μm; S2, cleaning the surface of the metal workpiece substrate. Before using the metal workpiece, grind it with 600#, 1000#, and 1500# emery paper, then ultrasonically rinse it with ethanol and deionized water for 5 minutes respectively to ensure that there is no oil or other impurities on the surface of the metal workpiece, and then dry the metal workpiece with nitrogen gas flow; S3, taking 70 parts of the ball-milled copper alloy mixed powder, 30 parts of urea-formaldehyde microcapsules and 0.1 parts of silane coupling agent and dissolving them together in 60 parts of organic solvent, dissolving the mixture with a constant temperature stirrer, setting the temperature of the constant temperature stirrer to 60 ° C, the stirring speed to 600 rpm, the stirring time to 1 h, and putting it into an 80 ° C oven for 12 h to dry to obtain a prefabricated coating; S4, plating the metal workpiece by plasma spraying, pouring the prefabricated coating prepared in step S3 into the hopper of the spray gun, and spraying it onto the metal workpiece cleaned in step S2, wherein the working voltage of the spraying device is 100-200 V, the working current is 200-800 mA, the spraying temperature is 120-200 ° C, the operating pressure is 4-40 Kpa, and the spraying speed is 50-200 m / s, and then the sprayed metal workpiece is left at room temperature overnight for preliminary drying, and then the coating is cured in an oven at 80 ° C for 6 hours, and the first layer of coating, i.e., a dense coating, is plated on the surface of the metal workpiece; S5, dissolve 5-10 parts of organic compound in 90 parts of anhydrous ethanol by ultrasonic method to form solution A, and the ultrasonic dissolution is completed in an ultrasonic cleaning machine, the ultrasonic power is set to 240 W, and the time is set to 30 min. Add 0.2 parts of inhibitor and 0.3 parts of photocatalyst to solution A, stir and heat at 60 ° C for 90 min to obtain solution B, and stir solution B continuously at 60 ° C for 19 h with a condensation reflux device, and then adjust the pH of solution B to 4 with HAc to obtain white SiO2 sol and form a super hydrophobic film; S6, using an immersion extraction speed of 600 mm / min, vertically immerse the metal workpiece coated with a dense coating in step S4 into the white SiO2 sol obtained in step S5, solvothermally heat at 80°C for 8 h, and then anneal the coated metal workpiece at 120°C for 4 h to solidify the coating and remove the unreacted solvent.

[0023] Example 2: This example proposes an impact-resistant and wear-resistant coating, which is composed of the following raw materials in parts by weight: 80 parts of copper alloy, 20 parts of urea-formaldehyde microcapsules, 8 parts of organic compounds, 1.2 parts of silane coupling agents, 80 parts of organic solvents, 1.5 parts of inhibitors and 0.7 parts of photocatalysts.

[0024] The preparation and steps of the urea-formaldehyde microcapsules are consistent with those in Example 1.

[0025] This embodiment also provides a method for preparing an impact-resistant and wear-resistant coating, and the preparation method specifically comprises the following steps: S1, putting the copper alloy into a ball mill for grinding to obtain a copper alloy mixed powder of 5-8 μm; S2, cleaning the surface of the metal workpiece substrate. Before using the metal workpiece, grind it with 600#, 1000#, and 1500# emery paper, then ultrasonically rinse it with ethanol and deionized water for 5 minutes respectively to ensure that there is no oil or other impurities on the surface of the metal workpiece, and then dry the metal workpiece with nitrogen gas flow; S3, taking 80 parts of the ball-milled copper alloy mixed powder, 20 parts of urea-formaldehyde microcapsules and 1.5 parts of silane coupling agent and dissolving them together in 80 parts of an organic solvent, dissolving them with a constant temperature stirrer to obtain a mixture, the temperature of the constant temperature stirrer was set to 70 °C, the stirring speed was set to 800 rpm, and the stirring time was 1.5 h; S4, plating the metal workpiece by plasma spraying, pouring the prefabricated coating prepared in step S3 into the hopper of the spray gun, and spraying it onto the metal workpiece cleaned in step S2, wherein the working voltage of the spraying device is 100-200 V, the working current is 200-800 mA, the spraying temperature is 120-200 ° C, the operating pressure is 4-40 Kpa, and the spraying speed is 50-200 m / s, and then the sprayed metal workpiece is left at room temperature overnight for preliminary drying, and then the coating is cured in an oven at 80 ° C for 6 hours, and the first layer of coating, i.e., a dense coating, is plated on the surface of the metal workpiece; S5, 5-10 parts of organic compound are ultrasonically dissolved in 90 parts of anhydrous ethanol to form solution A, and the ultrasonic dissolution is completed in an ultrasonic cleaning machine, the ultrasonic power is set to 240 W, and the time is set to 30 min. 1.5 parts of inhibitor and 0.7 parts of photocatalyst are added to solution A, and stirred and heated at 60 ° C for 90 min to obtain solution B, and solution B is continuously stirred at 60 ° C for 19 h using a condensation reflux device, and then the pH of solution B is adjusted to 4 with HAc to obtain a white SiO2 sol to form a super hydrophobic film; S6, using an immersion extraction speed of 600 mm / min, vertically immerse the metal workpiece coated with a dense coating in step S4 into the white SiO2 sol obtained in step S5, solvothermally heat at 80°C for 8 h, and then anneal the coated metal workpiece at 120°C for 4 h to solidify the coating and remove the unreacted solvent.

[0026] Example 3: This example proposes an impact-resistant and wear-resistant coating, which is composed of the following raw materials in parts by weight: 90 parts of copper alloy, 10 parts of urea-formaldehyde microcapsules, 10 parts of organic compounds, 2 parts of silane coupling agents, 100 parts of organic solvents, 2 parts of inhibitors and 1 part of photocatalysts.

[0027] The preparation and steps of the urea-formaldehyde microcapsules are consistent with those in Example 1.

[0028] This embodiment also provides a method for preparing an impact-resistant and wear-resistant coating, and the preparation method specifically comprises the following steps: S1, putting the copper alloy into a ball mill for grinding to obtain a copper alloy mixed powder of 5-8 μm; S2, cleaning the surface of the metal workpiece substrate. Before using the metal workpiece, grind it with 600#, 1000#, and 1500# emery paper, then ultrasonically rinse it with ethanol and deionized water for 5 minutes respectively to ensure that there is no oil or other impurities on the surface of the metal workpiece, and then dry the metal workpiece with nitrogen gas flow; S3, 90 parts of the ball-milled copper alloy mixed powder, 10 parts of urea-formaldehyde microcapsules and 2 parts of silane coupling agent were dissolved in 100 parts of an organic solvent, and a mixture was obtained by dissolving the mixture using a constant temperature stirrer, the temperature of the constant temperature stirrer was set to 80 °C, the stirring speed was set to 1000 rpm, and the stirring time was 2 h; S4, plating the metal workpiece by plasma spraying, pouring the prefabricated coating prepared in step S3 into the hopper of the spray gun, and spraying it onto the metal workpiece cleaned in step S2, wherein the working voltage of the spraying device is 100-200 V, the working current is 200-800 mA, the spraying temperature is 120-200 ° C, the operating pressure is 4-40 Kpa, and the spraying speed is 50-200 m / s, and then the sprayed metal workpiece is left at room temperature overnight for preliminary drying, and then the coating is cured in an oven at 80 ° C for 6 hours, and the first layer of coating, i.e., a dense coating, is plated on the surface of the metal workpiece; S5, 10 parts of organic compound were ultrasonically dissolved in 90 parts of anhydrous ethanol to form solution A, and the ultrasonic dissolution was completed in an ultrasonic cleaning machine, the ultrasonic power was set to 240 W, and the time was set to 30 min. 2 parts of inhibitor and 1 part of photocatalyst were added to solution A, and stirred and heated at 60 ° C for 90 min to obtain solution B, and solution B was continuously stirred at 60 ° C for 19 h using a condensation reflux device, and then the pH of solution B was adjusted to 4 with HAc to obtain a white SiO2 sol to form a super hydrophobic film; S6, using an immersion extraction speed of 600 mm / min, vertically immerse the metal workpiece coated with a dense coating in step S4 into the white SiO2 sol obtained in step S5, solvothermally heat at 80°C for 8 h, and then anneal the coated metal workpiece at 120°C for 4 h to solidify the coating and remove the unreacted solvent.

[0029] Comparative Example 1: Compared with Example 2, Comparative Example 1 eliminates the addition of urea-formaldehyde microcapsules, and the remaining preparation methods and steps are consistent with Example 2.

[0030] Comparative Example 2: Compared with Example 2, Comparative Example 2 eliminates the addition of organic compounds, and the remaining preparation methods and steps are consistent with Example 2.

[0031] Comparative Example 3: Compared with Example 2, Comparative Example 3 eliminates the addition of photocatalyst, and the rest of the preparation methods and steps are consistent with Example 2.

[0032] Comparative Example 4: Compared with Example 2, Comparative Example 4 eliminates the addition of organic compounds and photocatalysts, and the rest of the preparation methods are consistent with Example 2.

[0033] Experimental example: Impact resistance test Sample plates with standard dimensions of 50 mm×120 mm×0.3 mm were prepared using the impact-resistant and wear-resistant coatings of Examples 1-3 and Comparative Examples 1-4, and the impact resistance of the samples was tested using the national standard GB / T 1732-93 on the determination method for impact resistance of paint films. The test was performed using an impact tester, and the coating sample plate was placed flat on an anvil, with the impacted portion of the sample 20 mm away from the edge. The weight was fixed at 25 cm from the slide by a control device, and the weight was pressed so that it fell freely on the punch. The weight was lifted and the sample was taken out. The presence or absence of cracks, wrinkles and peeling of the impact-resistant and wear-resistant coatings of Examples 1-3 and Comparative Examples 1-4 is recorded in Table 1.

[0034] Wear resistance test According to GB / T 23988-2009, the wear resistance of the prepared coating was tested by the falling sand method. The coatings for impact-resistant and wear-resistant coatings of Examples 1-3 and Comparative Examples 1-4 were sprayed on metal workpieces to prepare two test plates with a size of 70 mm × 150 mm, and the test was carried out using a wear-resistant falling sand experimental device. On each sample, a circular area with a diameter of about 25 mm was marked. Each circular area required 3 test points, and the average measured value of the coating thickness on each circular area was recorded. The sample was fixed on the tester, the switch was turned on, and the sand passed through the conduit and hit the test plate. The container installed at the bottom of the tester collected the falling sand, and the above operation was repeated until the coating was damaged.

[0035] Wear resistance includes the amount of abrasive used and the thickness of the coating. The wear resistance of the test coating is calculated using the formula A=V / T, where A is the wear resistance, V is the amount of abrasive used, and T is the coating thickness. The test results are shown in Table 1.

[0036] Self-healing performance test The materials used for the impact-resistant and wear-resistant coatings in Examples 1-3 and Comparative Examples 1-4 were used to prepare sample plates with a size of 12 mm×6 mm×0.6 mm. Scratches were made on the samples with a new razor. The depth of the scratches was about 70 μm to ensure that the coating was cut through. In order to induce the self-repairing effect of the coating, the damaged coating was heated in an oven at 50 °C for 12 h. The strain-stress test was performed by a tensile machine (EZ-LX, SHIMADZU, Japan). The test was carried out at room temperature at a speed of 0.5 N·min -1 The ratio of the force was increased until the sample produced a self-healing effect. The tensile test was used to quantitatively evaluate the self-healing effect. The formula was: healing rate % = healed tensile strength / original tensile strength × 100%, where the original tensile strength and the healed tensile strength were the tensile strengths obtained before and after the scratch was healed, respectively. The calculated healing rate is recorded in Table 1.

[0037] Self-cleaning performance test The prepared sample samples were tested for photocatalytic self-cleaning performance according to GB / T 23764-2009. The materials for impact-resistant and wear-resistant coatings of Examples 1-3 and Comparative Examples 1-4 were cut into standard sizes of 100 mm ± 2 mm. During the cutting process, care was taken to prevent contamination by organic pollutants such as oil and cross-infection between samples. The illumination on the sample surface was adjusted to 2.0 Mw / cm using an ultraviolet irradiation device. 2 , 25 h of ultraviolet irradiation, and then oleic acid was coated on the surface of the sample using the pulling method, that is, the sample was immersed in an oleic acid n-heptane solution. Pulling at a speed of 60 cm / min, and drying at 70 °C for 15 min. Then the black light was turned on to measure the minimum contact angle of water. The test results are recorded in Table 1.

[0038] Corrosion resistance test The corrosion resistance of the coating was tested by salt spray test. The samples were prepared by using the impact-resistant and wear-resistant coating materials of Examples 1-3 and Comparative Examples 1-4. The prepared coating surface was scratched with a scalpel, left to stand for 24 hours, and then placed in a salt spray test box to observe the corrosion behavior. During the test, the corrosion condition of the coating surface was checked regularly, and the corrosion area was rated according to the national standard GB / T 6464-2002. The corrosion rating of the metal was calculated according to the percentage of the total area occupied by the corrosion defects according to the following formula: Rp=3×(2-LogA), where Rp is the corrosion rating number, A is the percentage of the total area occupied by the metal corrosion, and the corrosion results are recorded as shown in Table 1.

[0039] Table 1 Performance test results

[0040] It can be seen from the performance test data in the table that the impact-resistant and wear-resistant coating provided by this scheme has good impact-resistant and wear-resistant properties, self-repairing properties, self-cleaning function and corrosion resistance. It uses low-cost copper alloy and urea-formaldehyde microcapsules as the main materials. The prepared urea-formaldehyde microcapsules can release the healing agent inside the capsule to self-repair and heal the cracks when cracks occur in the coating, thereby significantly increasing the service life of the coating. By adding hydrophobic SiO2 and photocatalyst CeO2, a dense silica skeleton is formed to accelerate the inhibition of coating corrosion, and the self-cleaning and corrosion resistance of the coating are significantly improved through the surface hydrophobicity and photocatalytic activity, and the stability of the coating in various environments is improved, so that the coating can be widely used in various fields.

[0041] Figure 1 It is a cross-sectional view of the impact-resistant and wear-resistant coating model prepared by the present invention and a partially enlarged schematic diagram. From the cross-sectional view of the model, it can be seen that the urea-formaldehyde microcapsules are uniformly dispersed in the copper alloy, the urea-formaldehyde microcapsules can be tightly combined with the copper alloy, SiO2 and the inhibitor 8-hydroxyquinoline are uniformly adsorbed on the surface of the copper alloy coating, and the materials are tightly combined to form a composite coating. In addition, the partially enlarged view of the urea-formaldehyde microcapsules and the copper alloy can further show that the two are tightly cross-linked together, making the formed coating more dense and uniform, and the materials can achieve coordinated repair when damaged or cracked.

[0042] Figure 2 This is a diagram of the main self-repairing process of the impact-resistant and wear-resistant coating prepared by the present invention when cracks appear. When cracks appear in the coating, the urea-formaldehyde microcapsules are caused to rupture, releasing the healing agent dicyclopentadiene, thereby repairing the cracks.

[0043] Figure 3The hydrophobic stability diagram of Example 2 and Comparative Examples 1-4 prepared by the present invention when immersed in a 3.5 wt% NaCl solution shows that the stability of Comparative Example 1 is lower than that of Example 2, indicating that the added urea-formaldehyde microcapsules enhance the stability of the super-hydrophobic coating. Figure 3 As shown, the stability of Comparative Example 3 is also reduced compared with Example 2, indicating that the stability of the super-hydrophobic film formed with the assistance of the added photocatalyst is enhanced, and the materials influence each other and work together to enhance the self-cleaning and corrosion resistance of the coating.

[0044] In summary, through the verification of the embodiments and comparative examples, it can be known that the present invention prepares an impact-resistant and wear-resistant coating with self-repairing, self-cleaning and corrosion-resistant properties by mixing copper alloy and urea-formaldehyde microcapsules and utilizing plasma spraying technology. The urea-formaldehyde microcapsules and SiO2 incorporated in the present invention have the effect of significantly improving the self-repairing of the coating, and the addition of the photocatalyst CeO2 can effectively degrade the organic pollutants generated on the surface of the coating, thereby enhancing the self-cleaning effect of the super-hydrophobic SiO2 film. The present invention also has good corrosion resistance, and the coating of the present invention can be applied in the marine field and some wider fields.

[0045] The present invention and its embodiments are described above. The described embodiments are only some embodiments of the present invention, not all embodiments. The drawings are only one of many embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but only represents the selected embodiments of the present invention. Based on this, other specific embodiments of the present invention obtained by those skilled in the art under the inspiration of the technical solution without creative labor should fall within the protection scope of the present invention.

Claims

1. A method for preparing an impact-resistant and wear-resistant coating, characterized in that: The impact-resistant and wear-resistant coating includes a dense coating and a super-hydrophobic film from the inside to the outside, wherein the dense coating is prepared from the following components in parts by weight: 70-90 parts of copper alloy, 10-30 parts of urea-formaldehyde microcapsules, 60-100 parts of organic solvents and 0.1-2 parts of silane coupling agents; the super-hydrophobic film is prepared from the following components in parts by weight: 5-10 parts of organic compounds, 0.2-2 parts of inhibitors and 0.3-1 parts of photocatalysts; The method specifically comprises the following steps: S1, grinding the copper alloy to obtain a copper alloy mixed powder; S2, cleaning and drying the surface of the metal workpiece substrate; S3, dissolving the copper alloy mixed powder, urea-formaldehyde microcapsules and silane coupling agent in an organic solvent, stirring to obtain a mixture and drying to obtain a mixed coating; S4, coating the metal workpiece by spraying, spraying the mixed coating prepared in step S3 onto the metal workpiece to form a dense coating on the surface of the metal workpiece; S5, dissolving the organic compound in anhydrous ethanol to form solution A, adding an inhibitor and a photocatalyst to solution A, stirring and heating to obtain solution B, adjusting the pH to obtain a white SiO2 sol, and forming a super-hydrophobic film; S6, vertically immersing the metal workpiece coated with the dense coating in step S4 into the white SiO2 sol obtained in step S5, and performing solvent heating and annealing to solidify the coating to form an impact-resistant and wear-resistant coating.

2. The method for preparing an impact-resistant and wear-resistant coating according to claim 1, characterized in that: The urea-formaldehyde microcapsules are prepared from the following raw materials: urea, formaldehyde, sodium dodecylbenzene sulfonate and a healing agent; The preparation of the urea-formaldehyde microcapsules comprises the following steps: Y1, dissolving urea in formaldehyde to form a solution, adjusting the pH, heating and stirring to obtain a urea-formaldehyde prepolymer; Y2, dissolving sodium dodecylbenzene sulfonate in distilled water, stirring and mixing to form a solution, emulsifying the solution after it is completely dissolved, and then adding a healing agent, stirring continuously until an emulsion is formed; Y3, adding the urea-formaldehyde prepolymer obtained in step Y1 to the emulsion obtained in step Y2 and stirring to form a mixed solution, and maintaining the pH value of the mixed solution at 2.5 with sulfuric acid; Y4, heating and stirring the mixed solution obtained in step Y3 to obtain prefabricated microcapsules; Y5, cooling the prefabricated microcapsules obtained in step Y4 to room temperature, washing and drying to obtain urea-formaldehyde microcapsules.

3. The method for preparing an impact-resistant and wear-resistant coating according to claim 1, characterized in that: The chemical components of the copper alloy are as follows: Cu 60-90%, Sn 8-30% and Si 2-10% by weight.

4. The method for preparing an impact-resistant and wear-resistant coating according to claim 1, characterized in that: The organic solvent is xylene, and the silane coupling agent is A151.

5. The method for preparing an impact-resistant and wear-resistant coating according to claim 1, characterized in that: The organic compounds are TEOS and PFDS, and the volume ratio of TEOS to PFDS is 2:

1.

6. The method for preparing an impact-resistant and wear-resistant coating according to claim 1, characterized in that: The inhibitor is 8-hydroxyquinoline, and the photocatalyst is CeO2.

7. The method for preparing an impact-resistant and wear-resistant coating according to claim 1, characterized in that: In step S4, the spraying method adopts plasma spraying, the working voltage of the spraying device is 100-200 V, the working current is 200-800 mA, the spraying temperature is 120-200 ° C, the operating pressure is 4-40 Kpa, and the spraying speed is 50-200 m / s.

8. The method for preparing an impact-resistant and wear-resistant coating according to claim 2, characterized in that: The healing agent is dicyclopentadiene.

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