Preparation method of wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings

Abstract

The present invention relates to the field of coating technology, and specifically to a method for preparing a wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings. The present invention overcomes the problem of short service life of repaired hardware castings. The method for preparing the wear-resistant and corrosion-resistant coating material in the present invention comprises: subjecting modified phenolic resin, modified dispersant and other materials to stirring treatment to obtain a first component, subjecting composite ceramic powder, modified titanium dioxide and other materials to grinding treatment to obtain a second component, subjecting modified curing agent, composite defoaming agent and other materials to ultrasonic treatment to obtain a third component, and finally subjecting all the treated components and composite active agent to mixing treatment to obtain a wear-resistant and corrosion-resistant coating material. The coating material prepared by the present invention enables the repaired hardware castings to have excellent wear resistance and corrosion resistance, and has high hardness and compressive strength, and the coating material has strong adhesion to the hardware castings, and has significant application value in repairing defects in hardware castings.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to a method for preparing a wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings. Background Art

[0002] With the continuous development of industrial technology, metal castings are being used more and more widely in various fields. In industrial production, damage to metal castings is a common problem. Metal corrosion can cause damage to equipment, components or products and reduce their service life. Generally speaking, damage to metal castings during their service life is caused by the formation of surface defects (such as corrosion or wear). These defects reduce the friction resistance, wear resistance and corrosion resistance of metal castings. Repairing defects through some surface treatment, coating and other methods can solve the problems that arise today. Therefore, new coating materials are gradually being used in defect repair. However, there is a fatal disadvantage for metal castings. The repaired metal castings are still susceptible to wear and corrosion, resulting in failure to meet safety requirements in harsh environments such as high temperature, high load and high pressure.

[0003] Numerous experiments have proven that epoxy resin-based coating materials have excellent anti-corrosion properties and are one of the main types of anti-corrosion coatings. Epoxy resin-based coating materials have good tolerance to chemicals such as acids, alkalis, and salts, and can protect metal castings from corrosion in harsh chemical environments. They can effectively prevent chemical erosion of metal castings and extend the service life of metal castings. Epoxy resin-based coating materials also have excellent water resistance and are not easily penetrated or dissolved by water. They can maintain good performance in humid or underwater environments, and can prevent water from eroding and damaging metal castings. They are also resistant to the influence of natural environmental factors such as ultraviolet rays and temperature changes, and are not prone to aging, fading, and powdering. They have a long service life in outdoor environments. However, the wear resistance and impact resistance of epoxy resin-based coating materials after coating and curing are poor.

[0004] With the development of science and technology and the advancement of technology, many hardware castings now have defects that need to be repaired with coating materials. However, today's coating materials still have problems with poor wear resistance and corrosion resistance, resulting in a short service life of the repaired hardware castings, limiting their application in industry.

[0005] Therefore, a preparation method of wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings is proposed. Summary of the Invention

[0006] The purpose of the present invention is to design a preparation method of a wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings. The preparation method of the wear-resistant and corrosion-resistant coating material in the present invention is as follows: modified phenolic resin, modified dispersant and other materials are subjected to stirring treatment to obtain a first component, composite ceramic powder, modified titanium dioxide and other materials are subjected to grinding treatment to obtain a second component, modified curing agent, composite defoaming agent and other materials are subjected to ultrasonic treatment to obtain a third component, and finally all the treated components and composite active agent are mixed to obtain a wear-resistant and corrosion-resistant coating material. The coating material prepared by the present invention makes the repaired hardware castings have excellent wear resistance and corrosion resistance, and has high hardness and compressive strength, and the coating material has strong adhesion to the hardware castings, and has significant application value in repairing defects in hardware castings.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a method for preparing a wear-resistant and anti-corrosion coating material for repairing defects in hardware castings. The method for preparing the wear-resistant and anti-corrosion coating material comprises the following steps:

[0009] The modified phenolic resin, the first portion of epoxy resin E-51, and the modified dispersant are stirred to obtain a first component;

[0010] The composite ceramic powder, modified titanium dioxide and modified coupling agent are ground to obtain a second component;

[0011] The second portion of epoxy resin E-51, modified curing agent, and composite defoamer are ultrasonically treated to obtain a third component;

[0012] The first component, the second component, the third component and the composite active agent are mixed to obtain a wear-resistant and corrosion-resistant coating material.

[0013] Preferably, the specific steps of the stirring treatment are: 17 parts of modified phenolic resin, 25 parts of the first epoxy resin E-51, 5 parts of zinc phosphate and 6 parts of modified dispersant are put into a stirring tank, and stirred at a speed of 1500rpm-1900rpm and a temperature of 60℃-80℃ for 2h to obtain the first component.

[0014] Preferably, the preparation method of the modified phenolic resin is as follows: 4-6 parts of 3-fluorophenol and 25 parts of formaldehyde are put into 30 parts of toluene solution, stirred at a pH of 10 for pre-reaction, the stirring temperature is controlled to 55°C, and the stirring time is 3 hours to obtain a fluorine-containing precursor; 28 parts of phenol and 3 parts of sodium hydroxide are added to the fluorine-containing precursor, and the mixture is stirred for 1 hour and then transferred into a hydrothermal reactor, heated to 90°C, and reacted under autogenous pressure for 6 hours to 8 hours. After the reaction is completed, the mixture is centrifuged at 8000 rpm to obtain a solid product, and the solid product is vacuum dried at 60°C for 12 hours to obtain the modified phenolic resin.

[0015] Preferably, the preparation method of the modified dispersant is: 7 parts of sodium tripolyphosphate and 6-10 parts of triethanolamine are mixed to obtain a mixture A; 2 parts of hydrochloric acid are slowly dripped into the mixture A for 30 minutes to obtain a mixture B; 3 parts of maleic anhydride are added to the mixture B, and the mixture is stirred for 30 minutes and then transferred to a hydrothermal reactor, reacted at 120°C for 4h-6h, and centrifugally dried after the reaction to obtain the modified dispersant.

[0016] Preferably, the specific steps of the grinding treatment are: 9 parts of composite ceramic powder, 2 parts of glass fiber, 1-3 parts of modified titanium dioxide and 3 parts of modified coupling agent are placed in a ball mill, deionized water is used as the medium, and grinding is carried out for 10min-30min, and the particle size is 30μm-50μm to obtain a second component; the composite ceramic powder is composed of silicon carbide and aluminum oxide, and the weight ratio of the silicon carbide to the aluminum oxide is 1:1-3.

[0017] Preferably, the preparation method of modified titanium dioxide is as follows: 8 parts of tetrabutyl titanate are slowly added to 10 parts of anhydrous ethanol and stirred to form a solution A; 1 part of chromium nitrate is dissolved in 5 parts of deionized water to form a solution B; under stirring, the solution B is slowly added dropwise to the solution A, and 0.5 parts of glacial acetic acid is added as an inhibitor, and stirring is continued for 2 hours to form a uniform sol; the sol is allowed to stand at 60°C to allow it to undergo a gelation process to form a wet gel; the wet gel is dried at 40°C to remove the solvent and moisture therein to obtain a dry gel; and the dry gel is then calcined in a muffle furnace at 450°C-550°C for 2 hours under a nitrogen atmosphere with a heating rate of 10°C / min to obtain modified titanium dioxide.

[0018] Preferably, the preparation method of the modified coupling agent is as follows: dissolving 20 parts of γ-aminopropyltriethoxysilane in 10 parts of toluene to obtain solution C; dissolving 12 parts of epoxy resin E-44 and 0.5 parts of glacial acetic acid in 10 parts of toluene to obtain solution D; slowly adding the solution D dropwise to the solution C, followed by stirring at 60°C-76°C for 90min-130min, washing with ethanol after the reaction is completed and drying in a vacuum drying oven at 60°C for 12h to obtain the modified coupling agent.

[0019] Preferably, the specific steps of ultrasonic treatment are: putting the second portion of epoxy resin, modified curing agent and composite defoaming agent into a beaker and then putting it into an ultrasonic machine, ultrasonicating at 70°C-90°C for 5 hours at a power of 120W to obtain a third component; the composite defoaming agent is a mixture of DF-455 and SH-201, and the weight ratio of the DF-455 to the SH-201 is 2-4:3.

[0020] Preferably, the preparation method of the modified curing agent is as follows: under nitrogen protection, 6 parts of toluene diisocyanate are added to a reaction vessel, the temperature is stirred and raised to 40°C, 2 parts of butyl acetate solution are added dropwise, the temperature is controlled between 40°C and 80°C, and the reaction is kept warm for 6 hours. When the -NCO content is 8.1%-8.5%, 1 part of benzoyl chloride is added to terminate the reaction, and the modified curing agent is obtained by centrifugation.

[0021] Preferably, the specific steps of the mixing treatment are: putting the first component, the second component, the third component and the composite active agent into a mixer, mixing them at 150°C at a speed of 850rpm-1050rpm for 11min-15min to obtain a wear-resistant and anti-corrosion coating material; the composite active agent is a mixture of ethylenediamine, stearic acid and n-dodecyl mercaptan, and the weight ratio of the ethylenediamine, the stearic acid and the n-dodecyl mercaptan is 2:1:1-3.

[0022] Preferably, the wear-resistant and corrosion-resistant coating material is used in repairing defects in hardware castings.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention uses the first component of epoxy resin E-51 as the base material, adds a modified phenolic resin and a modified dispersant, and stirs the mixture to improve the corrosion resistance of repaired hardware castings. The phenolic resin is fluorine-modified to obtain a modified phenolic resin with good chemical stability. The modified phenolic resin can form a dense protective film on the surface of the hardware casting, preventing chemicals such as acids, alkalis, and salts from contacting the hardware casting, thereby extending the service life of the hardware casting in harsh chemical environments. The sodium tripolyphosphate and triethanolamine are acid-base modified to obtain a modified dispersant that can evenly disperse the materials, making the coating material more dense, effectively preventing corrosive media such as water, oxygen, and ions from penetrating the surface of the hardware casting, improving the corrosion resistance of the hardware casting and extending its service life. The modified phenolic resin and the modified dispersant synergistically form a dense film on the surface of the hardware casting, thereby improving its corrosion resistance, with a corrosion depth of only 18.7 μm.

[0025] 2. The present invention adds composite ceramic powder and modified titanium dioxide to the second component for grinding. The two materials can work synergistically to improve the impact strength of the repaired hardware casting. After the composite ceramic powder is combined with the hardware casting, its overall strength can be enhanced. When subjected to external force impact, the ceramic phase can absorb and disperse energy, thereby improving the impact resistance of the hardware casting, preventing the coating material from cracking or falling off, and allowing the hardware casting to maintain good performance when subjected to dynamic loads or impact loads. The modified titanium dioxide prepared using chromium-doped titanium dioxide has high strength and can play a reinforcing role when uniformly dispersed in the coating material, thereby improving the impact strength of the coating material and extending the service life of the hardware casting. The composite ceramic powder can fill the larger pores in the coating material, while the modified titanium dioxide has a smaller particle size and can fill the tiny gaps between the coating materials. The two work together to make the coating material more dense and improve the impact strength of the repaired hardware casting. The final impact strength is 94Kg.cm.

[0026] 3. In the third component, the present invention uses the second component of epoxy resin E-51 as the matrix material, adds a modified curing agent and a composite defoamer, and performs ultrasonic treatment to improve the hardness of the repaired hardware casting. After the composite defoamer eliminates bubbles, the porosity and defects in the coating material are reduced. The modified curing agent, modified with epoxy groups, promotes the full crosslinking and curing of the epoxy resin and other components in the coating material, forming a denser three-dimensional network structure. This synergistic effect greatly improves the density of the coating material. After the composite defoamer eliminates bubbles, it prevents structural damage caused by bubbles, making the coating material repaired on the hardware casting more uniform and complete. This allows the mechanical properties imparted by the modified curing agent to be better utilized, and the hardness of the repaired hardware casting is increased, reaching a Vickers hardness of 986 HV.

[0027] 4. The present invention incorporates a modified coupling agent into the second component. This material strengthens the bond between the first, second, and third components, thereby improving the adhesion between the coating material and the metal casting. The modified coupling agent, prepared by trimerization of toluene diisocyanate, reacts chemically with the hydroxyl groups on the surface of the modified titanium dioxide at one end and cross-links with the epoxy resin in the coating material at the other end, thereby tightly bonding the metal casting to the coating material. This significantly improves the adhesion of the coating material and makes it less likely to fall off the metal casting surface. Furthermore, an activation treatment can be performed on the metal casting surface to increase its surface roughness and active sites, allowing the coating material to better contact and bond with the metal casting surface, further enhancing adhesion, with a bonding strength of 56.7 MPa.

[0028] 5. The present invention adds a composite active agent during the mixing process of the first, second, and third components, improving the wear resistance of the repaired hardware casting. The composite active agent promotes the formation of a denser and more stable passivation film on the surface of the hardware casting and participates in the curing reaction of the coating material, promoting the formation of a more complete cross-linked network structure within the coating material, thereby increasing the hardness of the coating and thus improving its wear resistance. Heat and mixing all the treated components in a mixer effectively disperses the components and allows the different functional components to fully contact and interact, thereby enhancing their synergistic effects. The final wear loss is 0.48 mg / h. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow chart of the preparation method of the present invention.

[0030] Figure 2 This is a graph of the wear amount of Example 37, Examples 40-45 and Comparative Examples 17-20 of the present invention. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 making creative efforts are within the scope of protection of the present invention.

[0032] Specific reference Figures 1 to 2 The present invention provides a method for preparing a wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings. The technical solution is as follows:

[0033] The substance information involved in the present invention is as follows:

[0034] DF-455: purchased from Dongguan Defeng Defoaming Agent Co., Ltd.; SH-201: purchased from Hubei Longsheng Sihai New Materials Co., Ltd.

[0035] Example 1

[0036] Preparation of modified phenolic resin:

[0037] 4 parts of 3-fluorophenol and 25 parts of formaldehyde are placed in 30 parts of toluene solution, stirred for pre-reaction at a pH of 10, the stirring temperature is controlled to 55° C., and the stirring time is 3 hours to obtain a fluorine-containing precursor; 28 parts of phenol and 3 parts of sodium hydroxide are added to the fluorine-containing precursor, and the mixture is stirred for 1 hour, then transferred into a hydrothermal reactor, heated to 90° C., and reacted under autogenous pressure for 6 hours. After the reaction is completed, the mixture is centrifuged at 8000 rpm to obtain a solid product, and the solid product is vacuum dried at 60° C. for 12 hours to obtain a modified phenolic resin.

[0038] Preparation of modified dispersant:

[0039] 7 parts of sodium tripolyphosphate and 6 parts of triethanolamine were mixed to obtain a mixture A; 2 parts of hydrochloric acid were slowly added dropwise to the mixture A for 30 minutes to obtain a mixture B; 3 parts of maleic anhydride were added to the mixture B, and the mixture was stirred for 30 minutes and then transferred to a hydrothermal reactor, reacted at 120° C. for 4 hours, and centrifugally dried after the reaction to obtain a modified dispersant.

[0040] Preparation of modified titanium dioxide:

[0041] 8 parts of tetrabutyl titanate are slowly added to 10 parts of anhydrous ethanol and stirred evenly to form solution A; 1 part of chromium nitrate is dissolved in 5 parts of deionized water to form solution B; under stirring conditions, the solution B is slowly added dropwise to the solution A, and 0.5 parts of glacial acetic acid is added as an inhibitor, and stirring is continued for 2 hours to form a uniform sol; the sol is allowed to stand at 60°C to allow it to undergo a gelation process to form a wet gel; the wet gel is dried at 40°C to remove the solvent and moisture therein to obtain a dry gel; then the dry gel is calcined in a muffle furnace at 450°C for 2 hours under a nitrogen atmosphere with a heating rate of 10°C / min to obtain modified titanium dioxide.

[0042] Preparation of modified coupling agent:

[0043] 20 parts of γ-aminopropyltriethoxysilane were dissolved in 10 parts of toluene to obtain solution C; 12 parts of epoxy resin E-44 and 0.5 parts of glacial acetic acid were dissolved in 10 parts of toluene to obtain solution D; the solution D was slowly added dropwise to the solution C, followed by stirring at 60°C for 90 minutes. After the reaction was completed, the mixture was washed with ethanol and dried in a vacuum drying oven at 60°C for 12 hours to obtain a modified coupling agent.

[0044] Preparation of modified curing agent:

[0045] Under nitrogen protection, 6 parts of toluene diisocyanate were added to the reaction vessel, the temperature was stirred and raised to 40°C, 2 parts of butyl acetate solution were added dropwise, the temperature was controlled at 40°C, and the reaction was kept warm for 6 hours. When the -NCO content was 8.1%, 1 part of benzoyl chloride was added to terminate the reaction, and the modified curing agent was obtained by centrifugation.

[0046] Preparation of wear-resistant and anti-corrosion coating materials:

[0047] 17 parts of modified phenolic resin, 25 parts of the first epoxy resin E-51, 5 parts of zinc phosphate and 6 parts of modified dispersant were added to a stirring kettle, and stirred at a speed of 1500 rpm and a temperature of 60° C. for 2 hours to obtain a first component;

[0048] 9 parts of composite ceramic powder, 2 parts of glass fiber, 1 part of modified titanium dioxide and 3 parts of modified coupling agent were placed in a ball mill and ground with deionized water for 10 minutes to obtain a particle size of 30 μm, thereby obtaining a second component; the composite ceramic powder is composed of silicon carbide and aluminum oxide, and the weight ratio of the silicon carbide to the aluminum oxide is 1:1;

[0049] The second portion of epoxy resin, modified curing agent, and composite defoamer were placed in a beaker and then placed in an ultrasonic machine. Ultrasonication was performed at 70°C for 5 hours at a power of 120 W to obtain a third component. The composite defoamer was prepared by mixing DF-455 and SH-201, with the weight ratio of DF-455 to SH-201 being 2:3.

[0050] The first component, the second component, the third component and the composite active agent are put into a mixer and mixed at a speed of 850 rpm at 150°C for 11 minutes to obtain a wear-resistant and anti-corrosion coating material; the composite active agent is a mixture of ethylenediamine, stearic acid and n-dodecyl mercaptan, and the weight ratio of the ethylenediamine, the stearic acid and the n-dodecyl mercaptan is 2:1:1.

[0051] Example 2-13

[0052] With reference to the parameter conditions of the preparation method in Example 1, the specific differences are shown in Table 1.

[0053] Table 1 Parameter conditions of Examples 1-13

[0054]

[0055] Comparative Example 1 refers to the parameters and conditions of the preparation method in Example 1, except that no modified phenolic resin is added.

[0056] Comparative Example 2 refers to the parameter conditions of the preparation method in Example 1, except that 3-fluorophenol is not added to the synthetic phenolic resin.

[0057] Comparative Example 3 refers to the parameter conditions of the preparation method in Example 1, except that no modified dispersant is added.

[0058] Comparative Example 4 refers to the parameter conditions of the preparation method in Example 1, except that the triethanolamine is not modified.

[0059] Example 14 Anticorrosion Ability

[0060] According to the standard GB / T 7998-2005, an intergranular corrosion test (IGC) was performed to test the final corrosion depths of Examples 1-13 and Comparative Examples 1-4. The results are shown in Table 2.

[0061] Table 2 Anticorrosion ability of Examples 1-13 and Comparative Examples 1-4

[0062] Example Corrosion depth / μm Example 1 35.4 Example 2 32.6 Example 3 34.9 Example 4 29.2 Example 5 31.5 Example 6 26.7 Example 7 28.5 Example 8 24.1 Example 9 26.5 Example 10 21.6 Example 11 23.4 Example 12 18.7 Example 13 21.3 Comparative Example 1 61.7 Comparative Example 2 54.3 Comparative Example 3 59.6 Comparative Example 4 51.2

[0063] As can be seen from Table 2, in Comparative Examples 1-2, if the modified phenolic resin is not added, the corrosion resistance of the repaired hardware casting is the worst. When only the phenolic resin is added, although the corrosion resistance is improved, the corrosion is still very deep, indicating that the addition of the modified phenolic resin can promote the improvement of the corrosion resistance of the coating material. In Comparative Examples 3-4, without the addition of the modified dispersant or the modification of the triethanolamine, the corrosion resistance of the repaired hardware casting is poorer than that of the embodiment. This shows that the modified dispersant plays an important role in the first component. If it is not added, it will cause agglomeration between the components, thereby affecting the reaction between the materials, thereby reducing the corrosion resistance of the repaired hardware casting. In Examples 1-5, some parameters in the synthetic modified phenolic resin were changed. The anti-corrosion performance of Example 4 was the best, with a corrosion depth of 29.2 μm. This is because the modified phenolic resin has good chemical stability and can form a dense protective film on the surface of the hardware casting, preventing chemicals such as acids, alkalis, and salts from contacting the hardware casting, thereby extending the service life of the hardware casting in harsh chemical environments. In Examples 6-9, some preparation parameters in the synthetic modified dispersant were changed. The anti-corrosion performance of the repaired hardware casting was the best when the amount of triethanolamine was 8 parts and the reaction time was 5 hours. The corrosion depth of Example 8 was only 24.1 μm. This is because the modified dispersant can make the material Uniform dispersion makes the coating material denser, which can effectively prevent corrosive media such as water, oxygen, and ions from penetrating into the surface of hardware castings, improve the corrosion resistance of hardware castings, and extend the service life of hardware castings; in Examples 10-13, the parameter conditions in the stirring treatment are changed, and Example 12 has the best anti-corrosion performance and the smallest corrosion depth of 18.7 μm, because the stirring treatment can make the modified phenolic resin, modified dispersant and epoxy resin fully contact and interpenetrate with each other to form a uniform multi-component system, and the modified phenolic resin and modified dispersant can synergistically form a dense film on the surface of the hardware casting, thereby improving its corrosion resistance and extending the service life of the hardware casting.

[0064] Examples 15-24

[0065] The parameter conditions of the preparation method in Example 12 are referred to, except that the preparation parameters of the composite ceramic powder and modified titanium dioxide and the process parameters of the grinding treatment are changed, as shown in Table 3.

[0066] Table 3 Parameters and conditions of Example 12 and Examples 15-24

[0067]

[0068] Comparative Example 5 refers to the parameter conditions of the preparation method in Example 12, except that no composite ceramic powder is added.

[0069] Comparative Example 6 refers to the parameter conditions of the preparation method in Example 12, except that only silicon carbide is added.

[0070] Comparative Example 7 refers to the parameter conditions of the preparation method in Example 12, except that only aluminum oxide is added.

[0071] Comparative Example 8 refers to the parameter conditions of the preparation method in Example 12, except that modified titanium dioxide is not added.

[0072] Comparative Example 9 refers to the parameters and conditions of the preparation method in Example 12, except that only titanium dioxide is added.

[0073] Example 25 Impact Strength Test

[0074] Fix Example 12, Examples 15-24 and Comparative Examples 5-9 on a fixture. According to the coating material properties and the expected impact strength, select a suitable weight and drop height. Release the weight to allow it to fall freely and impact the repaired surface. Observe and record the results. The results are shown in Table 4.

[0075] Table 4 Impact strength test of Example 12, Examples 15-24 and Comparative Examples 5-9

[0076] Example Impact strength / Kg.cm Example 12 75 Example 15 79 Example 16 76 Example 17 83 Example 18 80 Example 19 86 Example 20 82 Example 21 90 Example 22 88 Example 23 94 Example 24 91 Comparative Example 5 56 Comparative Example 6 61 Comparative Example 7 62 Comparative Example 8 59 Comparative Example 9 66

[0077] As can be seen from Table 4, in Comparative Examples 5-7, when no composite ceramic powder was added, the impact resistance of the repaired hardware castings was poor, which would shorten their service life. When only one ceramic powder was added, although the impact resistance was improved, it was still lower than that of the comparative example, because a single ceramic powder could not provide sufficient strength to withstand the impact, resulting in a decrease in the impact resistance of the repaired hardware castings. In Comparative Examples 8-9, no modified titanium dioxide was added or unmodified titanium dioxide was added, and the impact resistance of the repaired hardware castings was also significantly reduced, indicating that the presence of modified titanium dioxide can promote the improvement of impact resistance. In Examples 12 and 15-20, the preparation parameters of the composite ceramic powder and modified titanium dioxide were changed. The performance of Example 19 was the best, which was 86Kg.cm. This is because the composite ceramic powder can enhance the overall strength of the hardware casting after being combined with the hardware casting. When subjected to external force impact, the ceramic phase can absorb and disperse energy, improve the impact resistance of the hardware casting, prevent the coating material from cracking or falling off, and enable the hardware casting to maintain good performance when subjected to dynamic loads or impact loads. The modified titanium dioxide has a higher strength and can be evenly dispersed in the coating material to play a reinforcing role, thereby improving the impact strength of the coating material and extending the life of the hardware casting. Service life; In Examples 21-24, the parameter conditions of the grinding treatment are controlled, among which Example 23 has the best impact resistance, which is 94Kg.cm, because through the grinding treatment, larger particles can be refined to make the particle size distribution more uniform, which helps to achieve more uniform dispersion in the coating material, thereby improving the performance of the coating material; the composite ceramic powder can fill the larger pores in the coating material, and the modified titanium dioxide has a smaller particle size and can fill the tiny gaps between the coating materials. The two cooperate with each other to make the coating material denser, improve the impact strength of the repaired hardware castings, and extend the service life of the repaired hardware castings.

[0078] Examples 26-33

[0079] Referring to the parameter conditions of the preparation method in Example 23, the difference is that the preparation parameters of the modified curing agent and the composite defoaming agent and the process parameters of the ultrasonic treatment are changed, as shown in Table 5.

[0080] Table 5 Parameters and conditions of Example 23 and Examples 26-33

[0081]

[0082] Comparative Example 10 refers to the parameter conditions of the preparation method in Example 23, except that no modified curing agent is added.

[0083] Comparative Example 11 refers to the parameter conditions of the preparation method in Example 23, except that only toluene diisocyanate is added as a curing agent.

[0084] Comparative Example 12 refers to the parameter conditions of the preparation method in Example 23, except that no composite defoaming agent is added.

[0085] Comparative Example 13 refers to the parameter conditions of the preparation method in Example 23, except that only DF-455 is added.

[0086] Comparative Example 14 refers to the parameters and conditions of the preparation method in Example 23, except that only SH-201 is added.

[0087] Example 34 Vickers Hardness Test

[0088] The Vickers hardness of Example 23, Examples 26-33 and Comparative Examples 10-14 was tested by a Vickers hardness test, and the results are shown in Table 6.

[0089] Table 6 Vickers hardness test of Example 23, Examples 26-33 and Comparative Examples 10-14

[0090] Example Vickers hardness / HV Example 23 872 Example 26 893 Example 27 877 Example 28 929 Example 29 902 Example 30 958 Example 31 936 Example 32 986 Example 33 961 Comparative Example 10 756 Comparative Example 11 813 Comparative Example 12 784 Comparative Example 13 845 Comparative Example 14 836

[0091] It can be found from Table 6 that in Comparative Examples 10-11, when no modified curing agent was added or only toluene diisocyanate was added as a curing agent, it can be found that the hardness of the repaired hardware casting was not high, which shows that the modified curing agent can significantly improve the performance of the coating material, and the modification of toluene diisocyanate can improve its curing performance; in Comparative Examples 12-14, when no composite defoaming agent was added or only one defoaming agent was added, the hardness of the repaired hardware casting was still lower than that of the embodiment, indicating that the composite defoaming agent plays a more significant role in the coating material. In Examples 23 and 26-29, the parameter conditions for synthesizing the modified curing agent are controlled. At this time, the hardness of Example 28 is the highest, which is 929HV. This is because the modified curing agent can make the curing reaction more complete, increase the cross-linking density of the coating material, and form a more complete three-dimensional network structure, thereby improving the hardness of the repaired hardware casting; in Examples 30-31, the weight ratio of DF-455 and SH-201 is changed. The hardness of Example 30 is 958HV. Because the performance of a single defoaming agent is poor, the composite defoaming agent can eliminate internal bubbles before the coating material is cured, so that the coating material forms a uniform and dense structure, thereby improving the hardness of the repaired hardware casting; in Examples 32-33, controlling the temperature of the ultrasonic treatment can provide more energy for the molecules involved in the synthesis reaction, make the molecular motion more intense, increase the collision frequency and effective collision probability between molecules, thereby accelerating the chemical reaction rate. At this time, the Vickers hardness of Example 32 is 986HV. After the composite defoaming agent eliminates the bubbles, the pores and defects in the coating material are reduced, and the modified curing agent can promote the epoxy resin and other components in the coating material to fully cross-link and cure, forming a denser three-dimensional network structure. This synergistic effect greatly improves the density of the coating material; and after the bubbles are eliminated, the damage to the structure by the bubbles is avoided, making the coating material repaired on the hardware casting more uniform and complete, so that the mechanical properties given by the modified curing agent can be better exerted, and the hardness of the repaired hardware casting is improved.

[0092] Examples 35-38

[0093] Refer to the parameter conditions of the preparation method in Example 32, except that the preparation parameters of the modified coupling agent are changed, as shown in Table 7.

[0094] Comparative Example 15 refers to the parameter conditions of the preparation method in Example 32, except that no modified coupling agent is added.

[0095] Comparative Example 16 refers to the parameter conditions of the preparation method in Example 32, except that only γ-aminopropyltriethoxysilane is added as a coupling agent.

[0096] Example 39 Adhesion Test

[0097] The bonding strength of Example 32, Examples 35-38 and Comparative Examples 15-16 was tested by a pull-off test, and the results are shown in Table 7.

[0098] Table 7 Adhesion test of Example 32, Examples 35-38 and Comparative Examples 15-16

[0099]

[0100] It can be seen from Table 7 that in Example 32, Examples 35-38 and Comparative Examples 15-16, the coating material has poor adhesion and is easy to fall off after repair, thereby affecting the service life of the repaired hardware casting. However, the addition of the modified coupling agent can make the combination between the first component, the second component and the third component more compact, thereby improving the adhesion of the coating material and the hardware casting, and one end of the modified coupling agent molecule can bind to the hydroxyl group on the surface of the modified titanium dioxide. A chemical reaction occurs, and the other end can undergo a cross-linking reaction with the epoxy resin in the coating material, thereby tightly combining the hardware casting and the coating material, greatly improving the adhesion of the coating material, and making it less likely to fall off on the surface of the hardware casting; the surface of the hardware casting can also be activated to increase the roughness and active sites of the surface of the hardware casting, so that the coating material can better contact and combine with the surface of the hardware casting, further enhancing the adhesion. The bonding strength of Example 37 is 56.7MPa, which extends the service life of the repaired hardware casting.

[0101] Examples 40-45

[0102] Referring to the parameter conditions of the preparation method in Example 37, the difference is that the preparation parameters of the composite active agent and the process parameters of the mixing treatment are changed, as shown in Table 8.

[0103] Comparative Example 17 refers to the parameter conditions of the preparation method in Example 37, except that no composite active agent is added.

[0104] Comparative Example 18 refers to the parameter conditions of the preparation method in Example 37, except that only n-dodecyl mercaptan is added.

[0105] Comparative Example 19 refers to the parameters and conditions of the preparation method in Example 37, except that only ethylenediamine is added.

[0106] Comparative Example 20 refers to the parameter conditions of the preparation method in Example 37, except that only stearic acid is added.

[0107] Example 46 Wear Test

[0108] The wear test was carried out on Example 37, Examples 40-45 and Comparative Examples 17-20, and the mass change before and after wear was measured to calculate the wear rate. The results are shown in Table 8 and Figure 2 shown.

[0109] Table 8 Wear test of Example 37, Examples 40-45 and Comparative Examples 17-20

[0110]

[0111]

[0112] From Table 8 and Figure 2 It can be found that in Comparative Examples 17-20, Examples 37, and Examples 40-41, no composite active agent was added or only a single active agent was added. The wear resistance of the repaired hardware castings was poor and the problem of short life still existed. When the composite active agent was added, its presence could promote the formation of a denser and more stable passivation film on the surface of the hardware castings, and participate in the curing reaction of the coating material with the modified curing agent, promote the formation of a more complete cross-linked network structure inside the coating material, and improve the hardness of the coating, thereby improving its wear resistance. In Examples 42-45, the speed and time of the mixing process were controlled. Example 44 had the best wear resistance, with a wear loss of only 0.48 mg / h. This is because all the components after treatment were placed in a mixer for heating and mixing. When the speed was moderate, the reactants were able to fully contact, the reaction rate was accelerated, and it was beneficial to improve the synthesis efficiency. When the mixing time was too short, the components did not have time to fully mix and the expected uniformity could not be achieved. As the mixing time was extended, the components had more time to diffuse, penetrate, and evenly distribute with each other, and the mixing effect gradually improved, thereby better exerting the synergistic effect between them.

[0113] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings, characterized in that: The preparation method of the wear-resistant and anti-corrosion coating material comprises the following steps, measured by weight: The modified phenolic resin, the first portion of epoxy resin E-51, and the modified dispersant are stirred to obtain a first component; The composite ceramic powder, modified titanium dioxide and modified coupling agent are ground to obtain a second component; The second portion of epoxy resin E-51, modified curing agent, and composite defoamer are ultrasonically treated to obtain a third component; Mixing the first component, the second component, the third component and a composite active agent to obtain the wear-resistant and corrosion-resistant coating material; The modified phenolic resin is prepared by: adding 4-6 parts of 3-fluorophenol and 25 parts of formaldehyde to 30 parts of toluene solution, stirring at a pH of 10 for pre-reaction, controlling the stirring temperature to 55° C. and the stirring time to 3 hours, to obtain a fluorine-containing precursor; adding 28 parts of phenol and 3 parts of sodium hydroxide to the fluorine-containing precursor, stirring for 1 hour, and then transferring the mixture into a hydrothermal reactor, heating it to 90° C., reacting it under autogenous pressure for 6-8 hours, and after the reaction is completed, centrifuging it at 8000 rpm to obtain a solid product, and vacuum drying the solid product at 60° C. for 12 hours to obtain the modified phenolic resin; The modified dispersant is prepared by mixing 7 parts of sodium tripolyphosphate and 6-10 parts of triethanolamine to obtain a mixture A; slowly dripping 2 parts of hydrochloric acid into the mixture A for 30 minutes to obtain a mixture B; adding 3 parts of maleic anhydride to the mixture B, stirring for 30 minutes, and then transferring the mixture to a hydrothermal reactor, reacting at 120° C. for 4-6 hours, and centrifugally drying after the reaction to obtain the modified dispersant; The composite ceramic powder is composed of silicon carbide and aluminum oxide, and the weight ratio of the silicon carbide to the aluminum oxide is 1:1-3; The modified titanium dioxide preparation method comprises: slowly adding 8 parts of tetrabutyl titanate to 10 parts of anhydrous ethanol and stirring uniformly to form solution A; dissolving 1 part of chromium nitrate in 5 parts of deionized water to form solution B; slowly adding solution B dropwise to solution A under stirring conditions, adding 0.5 parts of glacial acetic acid as an inhibitor, and continuing stirring for 2 hours to form a uniform sol; standing the sol at 60° C. to allow it to undergo a gelation process to form a wet gel; drying the wet gel at 40° C. to remove the solvent and moisture therein to obtain a dry gel; and then calcining the dry gel in a muffle furnace at 450° C.-550° C. for 2 hours under a nitrogen atmosphere at a heating rate of 10° C. / min to obtain the modified titanium dioxide; The modified coupling agent is prepared by dissolving 20 parts of γ-aminopropyltriethoxysilane in 10 parts of toluene to obtain a solution C; dissolving 12 parts of epoxy resin E-44 and 0.5 parts of glacial acetic acid in 10 parts of toluene to obtain a solution D; slowly adding the solution D dropwise to the solution C, followed by stirring at 60° C. to 76° C. for 90 min to 130 min, washing with ethanol after the reaction is completed, and drying in a vacuum drying oven at 60° C. for 12 h to obtain the modified coupling agent; The preparation method of the modified curing agent comprises: adding 6 parts of toluene diisocyanate to a reaction vessel under nitrogen protection, heating the reaction vessel to 40° C. with stirring, adding 2 parts of butyl acetate solution dropwise, controlling the temperature between 40° C. and 80° C., and keeping the temperature to react for 6 hours. When the -NCO content reaches 8.1% to 8.5%, adding 1 part of benzoyl chloride to terminate the reaction, and centrifuging to obtain the modified curing agent; The composite defoamer is prepared by mixing DF-455 and SH-201, wherein the weight ratio of the DF-455 to the SH-201 is 2-4:3; The composite active agent is a mixture of ethylenediamine, stearic acid and n-dodecyl mercaptan, and the weight ratio of the ethylenediamine, the stearic acid and the n-dodecyl mercaptan is 2:1:1-3.

2. The method for preparing the wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings according to claim 1, characterized in that: The specific steps of the stirring treatment are: 17 parts of the modified phenolic resin, 25 parts of the first epoxy resin E-51, 5 parts of zinc phosphate and 6 parts of the modified dispersant are put into a stirring tank, and stirred at a speed of 1500 rpm-1900 rpm and a temperature of 60°C-80°C for 2 hours to obtain the first component.

3. The method for preparing the wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings according to claim 1, characterized in that: The specific steps of the grinding treatment are: putting 9 parts of the composite ceramic powder, 2 parts of glass fiber, 1-3 parts of the modified titanium dioxide and 3 parts of the modified coupling agent into a ball mill, using deionized water as the medium, grinding for 10 minutes to 30 minutes, and the particle size is 30μm-50μm to obtain the second component.

4. The method for preparing the wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings according to claim 1, characterized in that: The specific steps of the ultrasonic treatment are: putting the second epoxy resin, the modified curing agent and the composite defoaming agent into a beaker and then putting it into an ultrasonic machine, ultrasonicating at 70° C.-90° C. for 5 hours at a power of 120 W to obtain the third component.

5. The method for preparing the wear-resistant and corrosion-resistant coating material for repairing defects in hardware castings according to claim 1, characterized in that: The specific steps of the mixing treatment are: putting the first component, the second component, the third component and the composite active agent into a mixer, mixing them at 150° C. at a speed of 850 rpm-1050 rpm for 11 min-15 min to obtain the wear-resistant and anti-corrosion coating material.

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