Protective coating for titanium alloy hanger and preparation method of protective coating

Abstract

The invention discloses a protective coating for a titanium alloy hanger and a preparation method of the protective coating, and belongs to the technical field of coating preparation. Epoxy-siloxane hybrid resin and polysilazane are mixed to serve as a main resin system, so that the high adhesive force of the coating and a titanium alloy interface can be guaranteed, the high heat resistance of the system can be improved, and the service life of the coating is prolonged. The composite wear-resistant particles, the composite heat-conducting particles and the corrosion inhibitor are added into the system, the components interact with one another, the coating can be endowed with remarkable performance, and the composite wear-resistant particles and the composite heat-conducting particles do not need to be subjected to surface modification treatment before use and still have excellent compatibility with system resin; according to the present invention, the coating has characteristics of significant high temperature stability, significant wear resistance, significant corrosion resistance, easy prolonging of the service life of the titanium alloy hanger, and the overall preparation method of the protection coating material has advantages of simpleness, environmental protection, large-scale production, and high application value.

Description

Technical Field

[0001] The present invention relates to the field of coating preparation, and in particular, to a protective coating for titanium alloy hangers and a preparation method thereof. Background Art

[0002] Due to its excellent specific strength, corrosion resistance and biocompatibility, titanium alloy is widely used in fields such as aerospace, medical devices, ocean engineering and chemical equipment. However, titanium alloy still has the following problems in high-temperature, high-humidity, high-salt or strongly corrosive environments: 1. High-temperature oxidation: When serving for a long time above 500 °C, an oxide layer is easily formed on the surface, resulting in the degradation of mechanical properties; 2. Friction and wear: With relatively low hardness, it is easily worn under sliding or impact conditions; 3. Local corrosion: Pitting or stress corrosion cracking may occur in an environment containing halogen ions such as Cl-. Therefore, when using titanium alloy as a titanium alloy hanger for a large-scale coating line, it is difficult to balance the requirements of high-temperature stability, wear resistance, corrosion resistance and low-cost industrial application. Therefore, coating a protective coating on the surface of the titanium alloy hanger to improve the high-temperature stability, wear resistance and corrosion resistance of the titanium alloy hanger and enable it to have better applications is the main research direction at present.

[0003] There are also protective coatings for titanium alloys in the prior art. For example, the patent with Chinese patent application number CN201010617891.7 discloses a silicon carbide-doped glass-ceramic coating for titanium alloys. This coating is a coating slurry formed by mixing silicate glass powder passed through a 200-700 mesh sieve, silicon carbide powder passed through a 200-700 mesh sieve, and an organic binder. By further enhancing the high-temperature oxidation resistance effect of the coating on the basis of silicate glass powder, the service temperature of the coating is increased. Another example is that the Chinese patent application number CN200810010437.8 discloses a graphite mold coating for casting titanium and titanium alloys. This patent adds refractory aggregate powder, and the refractory aggregate is composed of at least one of yttrium oxide powder, yttrium rare earth oxide powder, and zirconium oxide powder. The particle size of the refractory material powder is less than 0.053 mm. This patent can effectively improve the filling ability of titanium liquid, reduce defects such as misruns, cold shuts, and cracks caused by graphite chilling; can significantly improve the surface finish of castings; has high thermal stability, and the thickness of the casting pollution layer is significantly lower than that of ordinary machined graphite molds; can improve the collapsibility of graphite molds during solidification and reduce the hindrance of the mold to the shrinkage of castings. Another example is that the Chinese patent number CN201410143170.5 discloses a surface protection coating for hot working of titanium alloys and its application. The surface protection coating for hot working of titanium alloys in this patent is prepared by mixing 10 parts of sodium silicate binder, 5-10 parts of industrial waste, and 4.5-10 parts of auxiliary filler by weight ratio. It can form a continuous protective coating under high-temperature action, effectively reducing the high-temperature oxidation and burning loss of titanium alloys during hot working without changing the original properties of the titanium alloy workpiece matrix. However, the protective coatings for titanium alloy fixtures in the prior art still have the problem of being difficult to balance high-temperature stability, wear resistance, and corrosion resistance. Summary of the Invention

[0004] Based on this, in order to solve the problem that the protective coatings for titanium alloy fixtures in the prior art still have the problem of being difficult to balance high-temperature stability, wear resistance, and corrosion resistance, the present invention provides a protective coating for titanium alloy fixtures and its preparation method. The specific technical solutions are as follows:

[0005] A protective coating for titanium alloy fixtures, the protective coating comprises the following components in parts by weight:

[0006] 50-60 parts of epoxy-siloxane hybrid resin, 15-20 parts of polysilazane, 5-20 parts of composite wear-resistant particles, 1-5 parts of composite heat-conducting particles, 1-7 parts of corrosion inhibitor, 7-9 parts of cross-linking agent, 0.5-2 parts of curing agent, 0.1-2 parts of leveling agent, and 0.5-3 parts of defoaming agent.

[0007] Further, the preparation method of the epoxy-siloxane hybrid resin is as follows:

[0008] Add a silicone precursor to an aqueous solution of isopropanol, add a catalyst, and magnetically stir at 40 °C to 50 °C for 1 h to 2 h, controlling the pH to be 8 to 9 to obtain a silicone prepolymer with a solids content of 20% to 30%.

[0009] Let the silicone prepolymer stand and age for 20 h to 24 h, then add epoxy resin, and mechanically stir at a temperature of 60 °C to 70 °C at a speed of 500 r / min to 1000 r / min for 3 h to 5 h, and then perform vacuum distillation to obtain an epoxy-silicone hybrid resin.

[0010] Further, the catalyst is tetramethylammonium hydroxide.

[0011] Further, the silicone precursor is at least one of γ-glycidoxypropyltrimethoxysilane and γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0012] Further, the weight ratio of the silicone precursor, the aqueous solution of isopropanol, the catalyst, and the epoxy resin is (8 to 10):(40 to 50):(0.5 to 2):(10 to 20).

[0013] Further, the composite wear-resistant particles are obtained by mixing nanodiamond, zirconia nanocrystals, and albite in a mass ratio of (1 to 5):(1 to 3):(1 to 12).

[0014] Further, the composite heat-conducting particles are obtained by mixing montmorillonite and hexagonal boron nitride nanosheets in a mass ratio of (1 to 6):(1 to 7).

[0015] Further, the corrosion inhibitor is at least one of benzotriazole microcapsules and chromium oxide.

[0016] Further, the cross-linking agent is at least one of amino silane and isocyanate.

[0017] In addition, the present invention also provides a preparation method of a protective coating for a titanium alloy fixture, and the preparation method includes the following steps:

[0018] Add the epoxy-silicone hybrid resin and polysilazane to a reaction kettle, stir at 40 °C to 60 °C at a speed of 200 r / min to 500 r / min for 30 min to 60 min, then add a cross-linking agent and a curing agent, and continue to stir for 15 min to 20 min to obtain a mixture A;

[0019] Slowly add the composite wear-resistant particles to the mixture A, and after the addition of the composite wear-resistant particles is completed, stir at a speed of 2000 r / min to 5000 r / min for 10 min to 15 min to obtain a mixture B;

[0020] Mix the heat-conducting particles and the corrosion inhibitor, disperse them, and then slowly add the mixture to Mixture B. Then add a leveling agent and an antifoaming agent, stir at a speed of 100 r / min to 300 r / min for 20 min to 30 min, and then perform vacuum defoaming treatment to obtain a protective coating for a titanium alloy fixture.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention mixes an epoxy-siloxane hybrid resin and a polysilazane as the main resin system, which can not only ensure strong adhesion between the coating and the titanium alloy interface, but also help improve the high heat resistance of the system. Composite wear-resistant particles, composite heat-conducting particles and a corrosion inhibitor are added to the system, and the components interact with each other, endowing the coating with remarkable properties. Moreover, the composite wear-resistant particles and the composite heat-conducting particles do not need to be surface-modified before use and still have excellent compatibility with the system resin, making the coating have remarkable high-temperature stability, wear resistance and corrosion resistance.

[0023] 2. The composite wear-resistant particles in the present invention are compounded with nanodiamond, zirconia nanocrystals and albite. The components act synergistically, which can not only significantly improve the surface wear resistance of the coating formed by the coating. Among them, the zirconia nanocrystals absorb impact energy through phase transformation toughening, and albite fills microcracks at high temperatures, which helps to extend the service life of the titanium alloy fixture.

[0024] 3. The composite heat-conducting particles of the present invention are compounded with montmorillonite and hexagonal boron nitride nanosheets. Among them, the layered structure of montmorillonite provides a lateral heat diffusion path, reducing local thermal stress. The axial thermal conductivity of the hexagonal boron nitride nanosheets is excellent, and a three-dimensional heat conduction network is formed with montmorillonite, which can effectively prevent the titanium alloy fixture from deforming due to local overheating and further improve the service life of the titanium alloy.

[0025] 4. The overall preparation method of the protective coating of the present invention is simple, environmentally friendly, can be mass-produced, and has high application value. Specific Embodiments

[0026] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with its embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and do not limit the protection scope of the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0028] A protective coating for a titanium alloy fixture in an embodiment of the present invention, the protective coating comprising the following components in parts by weight:

[0029] 50 to 60 parts of epoxy-siloxane hybrid resin, 15 to 20 parts of polysilazane, 5 to 20 parts of composite wear-resistant particles, 1 to 5 parts of composite heat-conducting particles, 1 to 7 parts of corrosion inhibitor, 7 to 9 parts of cross-linking agent, 0.5 to 2 parts of curing agent, 0.1 to 2 parts of leveling agent, and 0.5 to 3 parts of defoaming agent.

[0030] In one embodiment, the preparation method of the epoxy-siloxane hybrid resin is as follows:

[0031] Add a siloxane precursor to an aqueous solution of isopropyl alcohol, add a catalyst, magnetically stir at 40°C to 50°C for 1 h to 2 h, control the pH at 8 to 9, and obtain a siloxane prepolymer with a solid content of 20% to 30%;

[0032] Let the siloxane prepolymer stand and age for 20 h to 24 h, then add epoxy resin, mechanically stir at a temperature of 60°C to 70°C at a rotation speed of 500 r / min to 1000 r / min for 3 h to 5 h, and then perform vacuum distillation to obtain an epoxy-siloxane hybrid resin.

[0033] In one embodiment, the catalyst is tetramethylammonium hydroxide.

[0034] In one embodiment, the siloxane precursor is at least one of γ-glycidoxypropyltrimethoxysilane and γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0035] In one embodiment, the weight ratio of the siloxane precursor, the aqueous solution of isopropyl alcohol, the catalyst, and the epoxy resin is (8 to 10):(40 to 50):(0.5 to 2):(10 to 20).

[0036] In one embodiment, in the aqueous solution of isopropyl alcohol, the volume ratio of isopropyl alcohol to water is 1:(10 to 15).

[0037] In one embodiment, the temperature of the vacuum distillation is 95°C to 100°C.

[0038] In one embodiment, the composite wear-resistant particles are obtained by mixing nanodiamond, zirconia nanocrystals, and albite in a mass ratio of (1-5):(1-3):(1-12).

[0039] In one embodiment, the composite heat-conducting particles are obtained by mixing montmorillonite and hexagonal boron nitride nanosheets in a mass ratio of (1-6):(1-7).

[0040] In one embodiment, the corrosion inhibitor is at least one of benzotriazole microcapsules and chromium oxide.

[0041] In one embodiment, the crosslinking agent is at least one of aminosilane and isocyanate.

[0042] In one embodiment, the curing agent is at least one of methylhexahydrophthalic anhydride, dicyandiamide, and 2-methylimidazole.

[0043] In one embodiment, the leveling agent is polyether-modified silicone.

[0044] In one embodiment, the defoaming agent is BYK-066N.

[0045] In addition, the present invention also provides a method for preparing a protective coating for a titanium alloy fixture, and the preparation method includes the following steps:

[0046] Add epoxy-siloxane hybrid resin and polysilazane into a reaction kettle, stir at a speed of 200 r / min - 500 r / min for 30 min - 60 min at 40°C - 60°C, then add a crosslinking agent and a curing agent, and continue to stir for 15 min - 20 min to obtain mixture A;

[0047] Slowly add the composite wear-resistant particles into mixture A. After the addition of the composite wear-resistant particles is completed, stir at a speed of 2000 r / min - 5000 r / min for 10 min - 15 min to obtain mixture B;

[0048] Mix the heat-conducting particles and the corrosion inhibitor, after dispersion treatment, slowly add them into mixture B, then add a leveling agent and a defoaming agent, stir at a speed of 100 r / min - 300 r / min for 20 min - 30 min, and then perform vacuum defoaming treatment to obtain the protective coating for the titanium alloy fixture.

[0049] In one embodiment, the dispersion treatment is: adding the heat-conducting particles and the corrosion inhibitor into an ethanol solution, and performing ultrasonic treatment for 20 min - 60 min under the condition of 40 kHz - 50 kHz.

[0050] In the above solution, by optimizing the components and their ratios, and through the interaction of the components, the coating can be endowed with remarkable properties, making the coating have remarkable high-temperature stability, wear resistance and corrosion resistance.

[0051] The implementation scheme of the present invention will be described in detail below in conjunction with specific embodiments.

[0052] Example 1:

[0053] A preparation method of a protective coating for a titanium alloy fixture, the preparation method comprising the following steps:

[0054] By weight ratio, 9 parts of γ-glycidoxypropyltrimethoxysilane are added to an aqueous solution of 45 parts of isopropanol (the volume ratio of isopropanol to water is 1:10), 0.5 part of tetramethylammonium hydroxide is added, and magnetic stirring is carried out at 40 °C for 1 h, and the pH is controlled at 8-9 to obtain a silicone prepolymer with a solid content of 20%; then the silicone prepolymer is allowed to stand and age for 20 h, and then 18 parts of epoxy resin are added, and mechanical stirring is carried out at a temperature of 65 °C at a speed of 500 r / min for 4 h, and then vacuum distillation is carried out at a temperature of 95 °C to obtain an epoxy-siloxane hybrid resin;

[0055] By weight ratio, 50 parts of the epoxy-siloxane hybrid resin and 18 parts of polysilazane are added to a reaction kettle, and stirring treatment is carried out at 50 °C at a speed of 200 r / min for 35 min, then 7 parts of aminosilane and 1 part of methylhexahydrophthalic anhydride are added, and stirring is continued for 15 min to obtain a mixture A;

[0056] 9 parts of composite wear-resistant particles (obtained by mixing nanodiamond, zirconia nanocrystals and albite in a mass ratio of 4:2:3) are slowly added to the mixture A, and after the addition of the composite wear-resistant particles is completed, stirring treatment is carried out at a speed of 2000 r / min for 15 min to obtain a mixture B;

[0057] 4 parts of heat-conducting particles (obtained by mixing montmorillonite and hexagonal boron nitride nanosheets in a mass ratio of 2:2) and 5 parts of chromium oxide are mixed, added to an ethanol solution, ultrasonic treatment is carried out at 40 kHz for 30 min, then slowly added to the mixture B, then 0.2 part of polyether-modified silicone and 0.5 part of BYK-066N are added, stirring treatment is carried out at a speed of 200 r / min for 25 min, and then vacuum defoaming treatment is carried out to obtain a protective coating for a titanium alloy fixture.

[0058] Example 2:

[0059] A preparation method of a protective coating for a titanium alloy fixture, the preparation method comprising the following steps:

[0060] By weight percentage, 10 parts of γ-glycidoxypropyltrimethoxysilane were added to an aqueous solution of 48 parts of isopropanol (the volume ratio of isopropanol to water was 1:10), 0.8 part of tetramethylammonium hydroxide was added, and magnetic stirring was carried out at 45 °C for 1 h, with the pH controlled at 8-9 to obtain a silicone oligomer with a solid content of 20%; then the silicone oligomer was allowed to stand and age for 22 h, and then 20 parts of epoxy resin were added, and mechanical stirring was carried out at a temperature of 70 °C and a rotation speed of 600 r / min for 4 h, and then vacuum distillation was carried out at a temperature of 95 °C to obtain an epoxy-silicone hybrid resin;

[0061] By weight parts, 55 parts of the epoxy-silicone hybrid resin and 18 parts of polysilazane were added to a reaction kettle, and stirring treatment was carried out at 55 °C and a rotation speed of 300 r / min for 40 min, then 8 parts of aminosilane and 1 part of methylhexahydrophthalic anhydride were added, and stirring was continued for 20 min to obtain mixture A;

[0062] 10 parts of composite wear-resistant particles (obtained by mixing nanodiamond, zirconia nanocrystals, and albite in a mass ratio of 3:2:5) were slowly added to the mixture A, and after the addition of the composite wear-resistant particles was completed, stirring treatment was carried out at a rotation speed of 2000 r / min for 15 min to obtain mixture B;

[0063] 4 parts of heat-conducting particles (obtained by mixing montmorillonite and hexagonal boron nitride nanosheets in a mass ratio of 1:3) and 6 parts of chromium oxide were mixed, added to an ethanol solution, ultrasonic treatment was carried out at 42 kHz for 35 min, then slowly added to the mixture B, then 0.3 part of polyether-modified silicone and 1 part of BYK-066N were added, stirring treatment was carried out at a rotation speed of 300 r / min for 25 min, and then vacuum degassing treatment was carried out to obtain a protective coating for a titanium alloy fixture.

[0064] Example 3:

[0065] A preparation method of a protective coating for a titanium alloy fixture, the preparation method comprising the following steps:

[0066] By weight percentage, 9 parts of γ-glycidoxypropyltrimethoxysilane were added to an aqueous solution of 50 parts of isopropanol (the volume ratio of isopropanol to water was 1:10), 1 part of tetramethylammonium hydroxide was added, and magnetic stirring was carried out at 45 °C for 2 h, with the pH controlled at 8-9 to obtain a silicone oligomer with a solid content of 20%; then the silicone oligomer was allowed to stand and age for 24 h, and then 20 parts of epoxy resin were added, and mechanical stirring was carried out at a temperature of 70 °C and a rotation speed of 600 r / min for 5 h, and then vacuum distillation was carried out at a temperature of 95 °C to obtain an epoxy-silicone hybrid resin;

[0067] By weight ratio, 54 parts of epoxy-siloxane hybrid resin and 16 parts of polysilazane are added into a reaction kettle, stirred at 60 °C for 50 min at a rotation speed of 200 r / min, then 9 parts of aminosilane and 1 part of methylhexahydrophthalic anhydride are added, and stirring is continued for 20 min to obtain mixture A;

[0068] 11 parts of composite wear-resistant particles (obtained by mixing nanodiamond, zirconia nanocrystals and albite in a mass ratio of 3:3:5) are slowly added into the mixture A. After the addition of the composite wear-resistant particles is completed, stirring is carried out at a rotation speed of 2000 r / min for 15 min to obtain mixture B;

[0069] 4 parts of heat-conducting particles (obtained by mixing montmorillonite and hexagonal boron nitride nanosheets in a mass ratio of 3:1) and 7 parts of chromium oxide are mixed, added to an ethanol solution, ultrasonically treated at 45 kHz for 35 min, then slowly added into the mixture B, then 0.4 part of polyether-modified silicone and 0.8 part of BYK-066N are added, stirred at a rotation speed of 300 r / min for 30 min, and then subjected to vacuum defoaming treatment to obtain a protective coating for titanium alloy hangers.

[0070] Comparative Example 1:

[0071] Compared with Example 3, in Comparative Example 1, epoxy resin is used to replace epoxy-siloxane hybrid resin, and the others are the same as in Example 3.

[0072] Comparative Example 2:

[0073] Compared with Example 3, in Comparative Example 2, polysilazane is not added, and the others are the same as in Example 3.

[0074] Comparative Example 3:

[0075] Compared with Example 3, in Comparative Example 3, single nanodiamond is added as the wear-resistant particle, and the others are the same as in Example 3.

[0076] Comparative Example 4:

[0077] Compared with Example 3, in Comparative Example 4, single zirconia nanocrystals are added as the wear-resistant particles, and the others are the same as in Example 3.

[0078] Comparative Example 5:

[0079] Compared with Example 3, in Comparative Example 5, single albite is added as the wear-resistant particle, and the others are the same as in Example 3.

[0080] Comparative Example 6:

[0081] Compared with Example 3, in Comparative Example 6, composite wear-resistant particles are not added, and the others are the same as in Example 3.

[0082] Comparative Example 7:

[0083] Compared with Example 3, in Comparative Example 7, single-component montmorillonite is used as the heat-conducting particles, and the others are the same as in Example 3.

[0084] Comparative Example 8:

[0085] Compared with Example 3, in Comparative Example 8, single-component hexagonal boron nitride nanosheets are used as the heat-conducting particles, and the others are the same as in Example 3.

[0086] Comparative Example 9:

[0087] Compared with Example 3, in Comparative Example 9, no composite heat-conducting particles are added, and the others are the same as in Example 3.

[0088] Comparative Example 10:

[0089] Compared with Example 3, in Comparative Example 10, no corrosion inhibitor is added, and the others are the same as in Example 3.

[0090] The protective coating samples for titanium alloy fixtures prepared in Examples 1 to 3 and the comparative samples of the protective coatings for titanium alloy fixtures prepared in Comparative Examples 1 to 10 were subjected to performance tests under the same test conditions, and the results are shown in Table 1 below.

[0091] Among them, the test conditions are as follows:

[0092] The heat resistance was referred to GB / T1735-2009, 400 °C, 2 h; the adhesion test was referred to GB / T5210-2006, and it was tested after the heat resistance test at 400 °C for 2 h; the salt spray resistance test was referred to GB / T1771-2007, 1000 h; the abrasion resistance test was referred to GB / T1768-89, 500 g, 500 r, and it was tested after the heat resistance test at 400 °C for 2 h.

[0093] Table 1: Performance test results

[0094]

[0095]

[0096] From the data analysis in Table 1, it can be seen that after optimizing the components and their ratios, the present invention can not only ensure strong adhesion at the interface between the coating and the titanium alloy, but also contribute to improving the high heat resistance of the system. The overall compatibility is excellent, and the high-temperature stability, wear resistance, and corrosion resistance of the coating are excellent. From the data of Comparative Examples 1-2, it can be seen that the addition of epoxy-siloxane hybrid resin and polysilazane in the present invention has an obvious effect on the adhesion and heat resistance of the coating; from the data of Comparative Examples 3-6, it can be clearly known that the compounding of nanodiamond, zirconia nanocrystals, and albite as composite wear-resistant particles, with the components acting synergistically, can significantly improve the wear resistance of the coating; from the data analysis of Comparative Examples 7-9, it can be known that the compounding of montmorillonite and hexagonal boron nitride nanosheets as composite heat-conducting particles, where the layered structure of montmorillonite provides a lateral heat diffusion path to reduce local thermal stress, and the axial thermal conductivity of hexagonal boron nitride nanosheets is excellent and forms a three-dimensional heat-conducting network with montmorillonite, can effectively prevent the titanium alloy fixture from deforming due to local overheating; in Comparative Example 10, no corrosion inhibitor was added, resulting in problems such as blistering, slight cracking, and slight peeling of the coating during the salt spray test, indicating that the addition of an appropriate amount of corrosion inhibitor has a significant improvement effect on the corrosion resistance of the coating.

[0097] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0098] The above-described embodiments only represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. A protective coating for a titanium alloy fixture, characterized in that, The protective coating comprises the following components in parts by weight: 50 to 60 parts of epoxy-siloxane hybrid resin, 15 to 20 parts of polysilazane, 5 to 20 parts of composite wear-resistant particles, 1 to 5 parts of composite heat-conducting particles, 1 to 7 parts of corrosion inhibitor, 7 to 9 parts of crosslinking agent, 0.5 to 2 parts of curing agent, 0.1 to 2 parts of leveling agent, and 0.5 to 3 parts of defoaming agent.

2. The protective coating according to claim 1, characterized in that, The preparation method of the epoxy-siloxane hybrid resin is as follows: Add the siloxane precursor to an aqueous solution of isopropanol, add a catalyst, and magnetically stir at 40°C to 50°C for 1 h to 2 h, with the pH controlled at 8 to 9, to obtain a siloxane prepolymer with a solid content of 20% to 30%; Let the siloxane prepolymer stand and age for 20 h to 24 h, then add epoxy resin, and mechanically stir at a temperature of 60°C to 70°C and a speed of 500 r / min to 1000 r / min for 3 h to 5 h, and then perform vacuum distillation to obtain the epoxy-siloxane hybrid resin.

3. The protective coating according to claim 2, characterized in that, The catalyst is tetramethylammonium hydroxide.

4. The protective coating according to claim 3, characterized in that, The siloxane precursor is at least one of γ-glycidoxypropyltrimethoxysilane and γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

5. The protective coating according to claim 3, characterized in that, The weight ratio of the siloxane precursor, the aqueous solution of isopropanol, the catalyst, and the epoxy resin is (8 to 10):(40 to 50):(0.5 to 2):(10 to 20).

6. The protective coating according to claim 1, characterized in that, The composite wear-resistant particles are obtained by mixing nanodiamond, zirconia nanocrystals, and albite in a mass ratio of (1 to 5):(1 to 3):(1 to 12).

7. The protective coating according to claim 1, characterized in that, The composite heat-conducting particles are obtained by mixing montmorillonite and hexagonal boron nitride nanosheets in a mass ratio of (1 to 6):(1 to 7).

8. The protective coating according to claim 1, characterized in that, The corrosion inhibitor is at least one of benzotriazole microcapsules and chromium oxide.

9. The protective coating according to claim 1, characterized in that, The crosslinking agent is at least one of aminosilane and isocyanate.

10. A preparation method of a protective coating for a titanium alloy fixture, characterized in that, The preparation method is used to prepare the protective coating for the titanium alloy fixture as described in any one of claims 1 to 9, and the preparation method comprises the following steps: Add the epoxy-siloxane hybrid resin and polysilazane to a reaction kettle, stir at 40°C to 60°C and a speed of 200 r / min to 500 r / min for 30 min to 60 min, then add the crosslinking agent and the curing agent, and continue stirring for 15 min to 20 min to obtain mixture A; Slowly add the composite wear-resistant particles to mixture A, and after the addition of the composite wear-resistant particles is completed, stir at a speed of 2000 r / min to 5000 r / min for 10 min to 15 min to obtain mixture B; Mix the heat-conducting particles and the corrosion inhibitor, perform dispersion treatment, then slowly add them to mixture B, then add the leveling agent and the defoaming agent, stir at a speed of 100 r / min to 300 r / min for 20 min to 30 min, perform reduced-pressure distillation, and then perform vacuum defoaming treatment to obtain the protective coating for the titanium alloy fixture.

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