WC-CoCr wear-resistant coating and preparation method thereof

Abstract

The invention relates to a WC-CoCr wear-resistant coating and a preparation method thereof. The WC-CoCr wear-resistant coating comprises an organic silicon resin layer and a WC-CoCr layer from top to bottom, the organic silicon resin layer comprises the following components in parts by mass: 40-80 parts of silicone oil, 5-15 parts of modified organic silicon resin, 1-5 parts of an auxiliary agent and a solvent; wherein the modified organic silicon resin is obtained by reacting tungsten carbide, a silane coupling agent, butanetetracarboxylic acid, epoxy resin, ethanolamine and amino silicon oil. According to the invention, the compatibility among different materials is effectively improved, various properties such as wear resistance, corrosion resistance and durability of the coating are enhanced, the protective function can be durably played in various environments, the problems in the prior art are solved, the application range of the WC-CoCr coating is expanded, and the WC-CoCr coating has a good application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to a WC-CoCr wear-resistant coating and a preparation method thereof. Background Art

[0002] WC-CoCr is a composite material composed of tungsten carbide hard phase and cobalt and chromium bonding phase. It is widely used in surface wear resistance, corrosion protection or remanufacturing repair of mechanical parts due to its high hardness, high toughness and excellent wear and corrosion resistance. WC-CoCr coating is usually sprayed by supersonic flame spraying (HVOF) and other processes. The higher flame velocity and lower flame temperature help to reduce the degree of oxidation and decarburization of WC particles, thereby preparing a coating with excellent performance.

[0003] In view of the growing performance requirements of coatings in various complex working environments, especially in the face of multiple extreme conditions such as high temperature, heavy load and highly corrosive media, developing high-performance WC-CoCr coatings and enhancing the comprehensive capabilities of WC-CoCr coatings have become key tasks that need to be urgently addressed in the fields of new material exploration, surface engineering technology advancement and remanufacturing.

[0004] Although the current WC-CoCr coating has good hardness, wear resistance, corrosion resistance and other properties, the single metal coating has defects in water resistance, fineness and durability, and the raw material cost is high, which limits the application scope of this type of material. The prior art also has a solution of further coating organic resin or lubricant on the outside of the WC coating, which can improve the waterproof, oil-proof and anti-sticking ability of the base material, but the organic resin has poor affinity with the WC-CoCr material, and the bonding degree between multiple coatings is low, which affects the original performance of the coating, resulting in reduced wear resistance, corrosion resistance and other properties, and it is difficult to meet the high requirements of market applications.

[0005] In summary, it is urgent to develop a new technical solution to solve the problems existing in the existing technology and meet the needs of current practical applications. Summary of the invention

[0006] Based on this, it is necessary to provide a WC-CoCr wear-resistant coating. The present invention further prepares a silicone resin layer on the surface of the WC-CoCr layer. By adding a modified silicone resin as a component, the compatibility between different materials is effectively improved, and the various properties of the coating, such as wear resistance, corrosion resistance and durability, are enhanced. The coating can exert its protective function for a long time in various environments, solves the problems existing in the prior art, expands the application scope of the WC-CoCr coating, and has good application prospects.

[0007] An object of the present invention is to provide a WC-CoCr wear-resistant coating, wherein the WC-CoCr wear-resistant coating comprises a silicone resin layer and a WC-CoCr layer from top to bottom;

[0008] The silicone resin layer comprises the following components in parts by weight:

[0009] Silicone oil 40-80 parts

[0010] Modified silicone resin 5-15 parts

[0011] 1-5 parts of additives

[0012] Solvents;

[0013] in,

[0014] The modified organic silicon resin is obtained by reacting tungsten carbide, silane coupling agent, butane tetracarboxylic acid, epoxy resin, ethanolamine and amino silicone oil.

[0015] Furthermore, the preparation method of the modified silicone resin comprises the following steps:

[0016] S1, mixing tungsten carbide and a silane coupling agent, heating for reaction, adding butane tetracarboxylic acid and an activator, and reacting under the protection of an inert gas to obtain an intermediate product 1;

[0017] S2, mixing the intermediate product 1, epoxy resin and catalyst, heating to react, then adding ethanolamine and solvent, and heating to react to obtain the intermediate product 2;

[0018] S3, mixing the intermediate product 2 and amino silicone oil, heating and reacting to obtain a modified silicone resin.

[0019] Furthermore, in step S1, the temperature of the heating reaction is 50-80°C.

[0020] Furthermore, in step S2, the temperature of the heating reaction is 80-90°C, and the temperature of the temperature-raising reaction is 120-140°C.

[0021] Furthermore, in step S3, the temperature of the heating reaction is 120-160°C.

[0022] Furthermore, the silicone oil includes hydroxy silicone oil and dimethyl silicone oil.

[0023] Furthermore, the auxiliary agent is selected from one or more of a cross-linking agent, a catalyst, a dispersant, and a film-forming auxiliary agent.

[0024] Another object of the present invention is to provide a method for preparing the above-mentioned WC-CoCr wear-resistant coating, comprising the following steps:

[0025] L1, spraying WC-CoCr mixed powder on the substrate surface, and baking to obtain a WC-CoCr layer;

[0026] L2. Coating a silicone resin layer on the surface of the WC-CoCr layer to obtain a WC-CoCr wear-resistant coating.

[0027] Furthermore, the spraying method is supersonic plasma spraying.

[0028] The present invention has the following beneficial effects:

[0029] The WC-CoCr wear-resistant coating of the present invention comprises a WC-CoCr bottom layer and an organosilicon resin layer, wherein the organosilicon resin layer is compounded with modified organosilicon resin and silicone oil and other components. The modified organosilicon resin first reacts tungsten carbide with an aminosilane coupling agent to introduce active amino groups on the surface, then reacts with a polycarboxylic acid to obtain an intermediate product 1 having a large number of carboxyl groups, then reacts with a bisphenol epoxy resin to introduce highly active epoxy groups, and then further polycondenses with ethanolamine using propylene glycol methyl ether as a solvent to obtain an intermediate product 2 with amino polyether grafted on the surface, and finally undergoes a grafting reaction with aminosilane to obtain a modified organosilicon resin. The organosilicon resin has both a tungsten carbide core and a high affinity with the WC-CoCr layer with WC as the main body, and also has a siloxane segment and good compatibility with components such as silicone oil, thereby effectively improving the bonding effect between the multiple layers, which is beneficial to improving the overall performance of the protective layer.

[0030] At the same time, the modified silicone resin of the present invention has better stability and mechanical properties due to the introduction of structures such as tungsten carbide and benzene rings. At the same time, the component also has a large number of active groups such as amino, carboxyl, and epoxy groups. Under the action of cross-linking agents and catalysts, it can form a network cross-linking structure and intermolecular forces with itself and silicone oil, thereby achieving higher strength and stability and further enhancing the performance of the silicone coating.

[0031] Therefore, the present invention prepares an organic silicon coating on the basis of a conventional WC-CoCr coating to form a multi-layer protective structure. The two can form a synergistic effect, improve the wear resistance, corrosion resistance, stability, durability and other properties of the coating, overcome the defects in the prior art, and have important significance for the development and application of WC-CoCr coatings. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0033] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0034] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers expressing, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all instances by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0035] The hydroxy silicone oil in the embodiment of the present invention is Haiduo Silicone Material H-202 high hydrogen silicone oil.

[0036] The amino silicone oil in the embodiment of the present invention is DY-N322.

[0037] The auxiliary agent in the embodiment of the present invention is a cross-linking agent (methyl tributylidene oxime silane), a PL-3 platinum catalyst, and dibutyltin dilaurate in a mass ratio of 4:0.7:0.3.

[0038] The solvent in the embodiment of the present invention is 120# solvent oil.

[0039] In the WC-CoCr in the embodiment of the present invention, WC:Co:Cr=86:5.6:8.4, m / m / m, and the average particle size is 200 nm.

[0040] The preparation method of the modified silicone resin in the embodiment of the present invention comprises the following steps:

[0041] S1. Using tetrahydrofuran as solvent, tungsten carbide and 3-aminopropyltriethoxysilane in a mass ratio of 1:2 are mixed, reacted at 60° C. for 6 h, and cooled and dried to obtain amino tungsten carbide;

[0042] Tetrahydrofuran is used as a solvent, butanetetracarboxylic acid and an activator solution (N,N'-carbonyldiimidazole-tetrahydrofuran solution with a mass concentration of 24.5%) are added, and the reaction is carried out at room temperature for 5 hours under nitrogen protection, and then the amino tungsten carbide (amino tungsten carbide: butanetetracarboxylic acid: N,N'-carbonyldiimidazole = 1:2.3:1.6, m / m / m) is added, and the reaction is continued for 6 hours. After centrifugation, washing and drying, an intermediate product 1 is obtained;

[0043] S2, the intermediate product 1, E-51 epoxy resin and triphenylphosphine in a mass ratio of 1:20:0.1 were blended, ultrasonically treated for 2 hours, and then reacted at 85°C for 24 hours, followed by addition of ethanolamine and propylene glycol methyl ether (intermediate product: ethanolamine: propylene glycol methyl ether = 1:6:40, m / m / m), and reacted at 140°C for 3 hours under nitrogen protection;

[0044] Then, propylene glycol methyl ether of the same mass as in the previous step was added, and the mixture was reacted at 140°C for 3 hours. After extraction, the mixture was washed with propylene glycol methyl ether and dried to obtain the intermediate product 2.

[0045] S3, mixing the intermediate product 2 and amino silicone oil in a mass ratio of 2:1, stirring for 2 hours, and then reacting at 150° C. for 3 hours, filtering, washing, and drying to obtain a modified silicone resin.

[0046] The "parts" in the embodiments of the present invention refer to parts by mass.

[0047] Example 1

[0048] A WC-CoCr wear-resistant coating, comprising a silicone resin layer and a WC-CoCr layer from top to bottom;

[0049] The silicone resin layer comprises the following components in parts by weight:

[0050]

[0051] The preparation method of the WC-CoCr wear-resistant coating comprises the following steps:

[0052] L1, spray WC-CoCr mixed powder on the substrate surface by supersonic plasma spraying, and bake at 100°C for 4h to obtain a WC-CoCr layer (thickness 100μm);

[0053] L2. Apply a silicone resin layer (50 μm thick) on the surface of the WC-CoCr layer, and obtain a WC-CoCr wear-resistant coating after curing.

[0054] Example 2

[0055] A WC-CoCr wear-resistant coating, comprising a silicone resin layer and a WC-CoCr layer from top to bottom;

[0056] The silicone resin layer comprises the following components in parts by weight:

[0057]

[0058]

[0059] The preparation method of the WC-CoCr wear-resistant coating comprises the following steps:

[0060] L1, spray WC-CoCr mixed powder on the substrate surface by supersonic plasma spraying, and bake at 100°C for 4h to obtain a WC-CoCr layer (thickness 100μm);

[0061] L2. Apply a silicone resin layer (50 μm thick) on the surface of the WC-CoCr layer, and obtain a WC-CoCr wear-resistant coating after curing.

[0062] Example 3

[0063] A WC-CoCr wear-resistant coating, comprising a silicone resin layer and a WC-CoCr layer from top to bottom;

[0064] The silicone resin layer comprises the following components in parts by weight:

[0065]

[0066] The preparation method of the WC-CoCr wear-resistant coating comprises the following steps:

[0067] L1, spray WC-CoCr mixed powder on the substrate surface by supersonic plasma spraying, and bake at 100°C for 4h to obtain a WC-CoCr layer (thickness 100μm);

[0068] L2. Apply a silicone resin layer (50 μm thick) on the surface of the WC-CoCr layer, and obtain a WC-CoCr wear-resistant coating after curing.

[0069] Comparative Example

[0070] A coating, the difference between this comparative example and Example 1 is that the preparation method of the modified silicone resin is replaced by:

[0071] Using tetrahydrofuran as solvent, tungsten carbide and 3-aminopropyltriethoxysilane in a mass ratio of 1:2 were mixed, reacted at 60°C for 6 hours, and then cooled and dried to obtain amino tungsten carbide;

[0072] The amino tungsten carbide and amino silicone oil in a mass ratio of 2:1 were mixed and stirred for 2 hours to obtain a modified silicone resin;

[0073] The other components and preparation methods are the same as those in Example 1.

[0074] Test Case

[0075] The coatings prepared in the examples and comparative examples were subjected to performance tests.

[0076] Test method:

[0077] The wear resistance test was carried out using a linear wear tester with a constant load of 20N, a swing stroke of 5mm, a sliding speed of 0.02m / s, and a sliding time of 1h. The weight change of each sample after wear was statistically analyzed.

[0078] Refer to GB / T 1771-2007 for salt spray resistance test.

[0079] The test results are shown in Table 1.

[0080] Table 1 Performance test results of coatings prepared in Example 1 and Comparative Examples 1-2

[0081] project Example 1 Example 2 Example 3 Comparative Example Weight reduction (mg) 7.2 6.6 6.4 25.5 Salt spray resistance (144h) No rust No rust No rust A little rust

[0082] According to Table 1, it can be concluded that the WC-CoCr wear-resistant coating prepared in the embodiment of the present invention has excellent wear resistance and corrosion resistance, extremely low weight loss due to wear, and no rust phenomenon occurs in a salt spray environment for a long time. However, in the comparative example, the modified silicone resin is replaced with a mixture of silane coupling agent-modified tungsten carbide and silicone oil, resulting in unsatisfactory compatibility improvement effect between the components, poor bonding effect between the multilayer coatings, and different degrees of reduction in the stability, wear resistance, and corrosion resistance of the coating, failing to achieve ideal performance improvement.

[0083] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0084] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A WC-CoCr wear-resistant coating, characterized in that: The WC-CoCr wear-resistant coating comprises a silicone resin layer and a WC-CoCr layer from top to bottom; The silicone resin layer comprises the following components in parts by weight: Silicone oil 40-80 parts Modified silicone resin 5-15 parts 1-5 parts of additives Solvents; in, The modified organic silicon resin is obtained by reacting tungsten carbide, silane coupling agent, butane tetracarboxylic acid, epoxy resin, ethanolamine and amino silicone oil.

2. The WC-CoCr wear-resistant coating according to claim 1, characterized in that: The preparation method of the modified silicone resin comprises the following steps: S1, mixing tungsten carbide and a silane coupling agent, heating for reaction, adding butane tetracarboxylic acid and an activator, and reacting under the protection of an inert gas to obtain an intermediate product 1; S2, mixing the intermediate product 1, epoxy resin and catalyst, heating to react, then adding ethanolamine and solvent, and heating to react to obtain the intermediate product 2; S3, mixing the intermediate product 2 and amino silicone oil, heating and reacting to obtain a modified silicone resin.

3. The WC-CoCr wear-resistant coating according to claim 2, characterized in that: In step S1, the temperature of the heating reaction is 50-80°C.

4. The WC-CoCr wear-resistant coating according to claim 2, characterized in that: In step S2, the temperature of the heating reaction is 80-90°C, and the temperature of the temperature-raising reaction is 120-140°C.

5. The WC-CoCr wear-resistant coating according to claim 2, characterized in that: In step S3, the temperature of the heating reaction is 120-160°C.

6. The WC-CoCr wear-resistant coating according to claim 1, characterized in that: The silicone oil includes hydroxy silicone oil and dimethyl silicone oil.

7. The WC-CoCr wear-resistant coating according to claim 1, characterized in that: The auxiliary agent is selected from one or more of a cross-linking agent, a catalyst, a dispersant, and a film-forming auxiliary agent.

8. The method for preparing the WC-CoCr wear-resistant coating according to any one of claims 1 to 7, characterized in that: The steps include: L1, spraying WC-CoCr mixed powder on the substrate surface, and obtaining a WC-CoCr layer after baking; L2. Coating a silicone resin layer on the surface of the WC-CoCr layer to obtain a WC-CoCr wear-resistant coating.

9. The method for preparing the WC-CoCr wear-resistant coating according to claim 8, characterized in that: The spraying method is supersonic plasma spraying.

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