A drawing-resistant coating for titanium alloy wire, its preparation method and application

Abstract

The present invention provides a drawing-resistant coating for titanium alloy wire. By weight, the raw materials for preparing the coating include 30-50 parts of binder, 20-40 parts of lubricant, 20-30 parts of solvent, 2-5 parts of dispersant, and 3-8 parts of curing agent. In the present invention, by using epoxy resin and acrylic resin as binders, the toughness and tensile resistance of the coating are effectively improved; by using a specific molybdenum disulfide material and using it together with materials such as binders and curing agents, the lubricating material is kept stably dispersed in the system, and the obtained drawing-resistant coating has excellent lubricity and drawing-resistant effect. When the coating is used, it can be evenly and stably coated on the surface of the titanium alloy wire, has good adhesion to the wire, is not easy to fall off and crack during the drawing of the titanium alloy wire, and has excellent lubricating and protecting effects on the material.

Description

Technical Field

[0001] The present invention relates to the technical field of titanium alloy processing, and particularly relates to a draw-resistant coating for titanium alloy wire, a preparation method thereof, and an application thereof. Background Art

[0002] Titanium alloy materials have a series of advantages such as high specific strength, low density, and high temperature resistance, and are widely used in modern aviation and aerospace industries. However, they also have characteristics such as high chemical activity and easy adhesion, and in the production process, it is extremely easy to avoid problems such as die adhesion and material wear. Titanium alloy drawing is a commonly used wire processing method, which has the advantages of high dimensional accuracy, high surface finish, and high efficiency. However, at the same time, since the billet needs to pass through the die during drawing, and the diameter and structure of the wire will change during drawing, problems such as surface wear and uneven wire dimensions are likely to occur.

[0003] In the prior art, a lubricating coating is often applied to the surface of titanium alloy materials to protect the titanium alloy materials. As an effective lubrication means, a solid lubricating coating has a low friction coefficient, can withstand a large load, and can be used in a wide temperature range. By using a bonded solid lubricating coating, the solid lubricant can be firmly bonded to the surface of the substrate, so that the friction becomes the friction between lubricating films. The base oil of the existing oil-based lubricating medium is usually mechanical oil, hydraulic oil, etc., which has poor adhesion and a small applicable temperature range. Especially during the drawing process, if the pass reduction rate of the material is large, the coating is prone to cracking, causing the material to directly contact the die and unable to provide good protection for the material. Summary of the Invention

[0004] In view of the above problems, on the one hand, the present invention provides a draw-resistant coating for titanium alloy wire. By weight, the raw materials of the coating include 30-50 parts of a binder, 20-40 parts of a lubricant, 20-30 parts of a solvent, 2-5 parts of a dispersant, and 3-8 parts of a curing agent.

[0005] Preferably, the binder is one or more mixtures of epoxy resin or acrylic resin.

[0006] Preferably, the epoxy equivalent of the epoxy resin is 100-250 g / eq, and the viscosity at 40 °C is 1000-2500 mPa·S. In the present invention, the epoxy resin is preferably epoxy resin E51.

[0007] Preferably, the acrylic resin is polyacrylic acid, and the weight-average molecular weight of the polyacrylic acid is 500-5000.

[0008] To improve the toughness and tensile resistance of the coating, more preferably, the binder is epoxy resin and acrylic resin; the mass ratio of the epoxy resin to the acrylic resin is 2 - 5:1. For example, 2:1, 3:1, 4:1, 5:1 can be enumerated, but it is not limited to the enumerated values, and other unenumerated values within this numerical range are equally applicable. More preferably, in the present invention, the mass ratio of the epoxy resin to the acrylic resin is 4:1.

[0009] Epoxy resin has the advantages of high bonding strength and low shrinkage rate, but it has high rigidity and poor toughness. The coating made from it is more brittle and has poor toughness during use. Especially when the coating is used for the drawing of titanium alloy wire and the like, coating cracking and other phenomena are likely to occur. In the present invention, epoxy resin and acrylic resin are used in combination. Especially when the mass ratio of epoxy resin to acrylic resin is 2 - 5:1, the epoxy equivalent of the epoxy resin is 100 - 250 g / eq, and the viscosity at 40 °C is 1000 - 2500 mPa·S, it can effectively improve the toughness and tensile properties of the coating; and it is more likely to combine with components such as lubricants in the system, keep the lubricating material stably dispersed in the system, and have better adhesion to the wire, thus achieving excellent lubrication effects. If the epoxy equivalent is too high, it may cause excessive cross-linking of the components in the system, resulting in agglomeration phenomena, affecting the uniform dispersion of other components in the system, and instead affecting the performance of the coating.

[0010] Preferably, the lubricant is one or a combination of molybdenum disulfide, graphite, graphene oxide, nano-yttrium oxide, talc powder, hexagonal boron nitride or tungsten disulfide.

[0011] Preferably, the lubricant is molybdenum disulfide. More preferably, the particle size of the molybdenum disulfide is 1 - 100 μm.

[0012] Molybdenum disulfide is a hexagonal crystal. Its special layered structure makes the layers slide between each other when subjected to friction, thus having excellent lubrication performance. In the present invention, a specific amount of molybdenum disulfide is used, and the particle size of molybdenum disulfide is limited to 1 - 100 μm. Under this condition, molybdenum disulfide can be more uniformly dispersed in the system, achieving the best lubrication effect. Molybdenum disulfide with too small particle size tends to agglomerate extremely, affecting the use of the coating; when the content of molybdenum disulfide is too low, it cannot form an effective lubricating layer on the material surface, resulting in adhesive wear on the material surface; but if the content is too high, its binding force with the resin becomes poor, and more abrasive particles will be generated during friction, causing more abrasive particle wear.

[0013] Preferably, the solvent is one or a mixture of acetone, xylene, methyl acetate, butyl acetate, isobutanol, isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether.

[0014] To effectively improve the solubility of the components in the system, preferably, the solvent is butyl acetate, isobutanol, or ethylene glycol monobutyl ether. More preferably, the mass ratio of butyl acetate, isobutanol, and ethylene glycol monobutyl ether is 3 - 5:3 - 5:3.

[0015] In the present invention, the solubility of each raw material is improved by using a combination of multiple solvents. The inventors found that when the mass ratio of butyl acetate, isobutanol, and ethylene glycol monobutyl ether used is 3 - 5:3 - 5:3, the solubility of each raw material is better, enabling the coating to be more evenly applied on the surface of the wire, and playing an excellent lubricating and protective role. Unexpectedly, in the system of the present invention, when several solvents are used together, it can also effectively increase the curing rate of the coating on the surface of the wire. The inventors analyzed that this may be due to the combined action of different solvents, which enables the resin and lubricant to be better dissolved and dispersed. And due to their relatively high polarity, when the coating is sprayed, especially when using electrostatic spraying, the coating can be more evenly dispersed. At the same time, the solvent contains active hydrogen atoms, which play a catalytic role in the cross-linking reaction between the acid anhydride and the resin, effectively increasing the curing rate. However, if there are too many active hydrogen atoms, they will first react with the acid anhydride to undergo an esterification reaction, thus consuming a large amount of acid anhydride curing agent, which will instead affect the curing of the coating.

[0016] Preferably, the dispersant is one or a mixture of several of dialkyl sulfosuccinates, monoglyceryl stearate, sodium polyoxyethylene alkylaryl ether sulfonate, polyoxyethylene alkylphenol ether, Tween - 20, Span - 80, polyethylene glycol, polyvinyl formal, and polyvinyl butyral.

[0017] Preferably, the dispersant is polyethylene glycol and polyvinyl butyral. In the present invention, preferably, the mass ratio of polyethylene glycol and polyvinyl butyral is 8 - 10:1.

[0018] More preferably, the polyethylene glycol is polyethylene glycol 400.

[0019] Preferably, the curing agent is one or a mixture of amine curing agents, phenolic curing agents, and acid anhydride curing agents.

[0020] Preferably, the curing agent is amine curing agent and acid anhydride curing agent. In the present invention, preferably, the mass ratio of amine curing agent and acid anhydride curing agent is 1:4 - 6.

[0021] Preferably, the amine curing agent is an aromatic amine curing agent. More preferably, the amine curing agent in the present invention is dapsone.

[0022] Preferably, the acid anhydride curing agent is one or a mixture of glutaric anhydride, phthalic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. More preferably, the acid anhydride curing agent in the present invention is methylhexahydrophthalic anhydride.

[0023] On the other hand, the present invention provides a method for preparing a draw-resistant coating for a titanium alloy wire, and the specific steps are as follows:

[0024] Add a binder, a dispersant, a solvent, a lubricant, and a curing agent into a reactor in sequence and mix them evenly to obtain the coating.

[0025] On the third aspect, the present invention provides the application of the draw-resistant coating in the processing of titanium alloy wires.

[0026] Beneficial effects:

[0027] (1) By using epoxy resin and acrylic resin as binders, the present invention effectively improves the toughness and tensile resistance of the coating. Combined with components such as lubricants in the system, the lubricating material is stably dispersed in the system, achieving a more excellent lubricating effect.

[0028] (2) By using a specific molybdenum disulfide material and using it together with materials such as binders and curing agents, the obtained draw-resistant coating has excellent lubricity and draw resistance. When the coating is used, it can be evenly and stably coated on the surface of the titanium alloy wire. The coating has good adhesion to the wire. During the drawing of the titanium alloy wire, the coating is not easy to fall off or crack, and has an excellent lubricating and protective effect on the material. Description of the drawings

[0029] Figure 1 is the titanium alloy wire after the coating of Example 1 of the present invention is applied;

[0030] Figure 2 is the surface coating morphology diagram of the titanium alloy wire after the coating of Example 1 of the present invention is applied;

[0031] Figure 3 is the drawing process diagram of the coating of the embodiment of the present invention during eye die drawing;

[0032] Figure 4 is the surface morphology diagram of the wire after drawing the wire coated with the coating of Example 1 of the present invention;

[0033] Figure 5 is the surface morphology diagram of the wire after drawing the wire coated with the coating of Example 3 of the present invention;

[0034] Figure 6 is the surface morphology diagram of the wire after drawing the wire coated with the coating of Example 4 of the present invention;

[0035] Figure 7 is the surface morphology diagram of the wire after drawing the wire coated with the coating of Example 6 of the present invention. Specific embodiments

[0036] The present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0037] Embodiment

[0038] Embodiment 1

[0039] In the first aspect of this embodiment, a drawing-resistant coating for titanium alloy wire is provided. By weight, the raw materials for preparing the coating include 40 parts of binder, 30 parts of lubricant, 25 parts of solvent, 3 parts of dispersant, and 5 parts of curing agent.

[0040] The binder is epoxy resin E51 and polyacrylic resin with a mass ratio of 4:1. The epoxy equivalent of epoxy resin E51 is 190 - 210 g / eq, and the viscosity (mPa·S) at 40 °C ≤ 2500, purchased from Wanqing Chemical Technology Co., Ltd.; the weight-average molecular weight of polyacrylic resin is 3000, purchased from Chengdu McCathy Chemical Co., Ltd.

[0041] The lubricant is molybdenum disulfide with an average particle size of 5 μm, purchased from Nangong Xindun Alloy Welding Materials Spraying Co., Ltd.

[0042] The solvent is butyl acetate, isobutanol, and ethylene glycol monobutyl ether with a mass ratio of 4:4:3.

[0043] The dispersant is polyethylene glycol and polyvinyl butyral with a mass ratio of 9:1. The polyethylene glycol is polyethylene glycol 400, purchased from Shandong Hengqiang Chemical Co., Ltd.; polyvinyl butyral is purchased from Chengdu McCathy Chemical Co., Ltd., with the model M005831.

[0044] The curing agent is dapsone (CAS No. 80 - 08 - 0) and methylhexahydrophthalic anhydride (CAS No. 25550 - 51 - 0) with a mass ratio of 1:5.

[0045] In the other aspect of this embodiment, a method for preparing a drawing-resistant coating for titanium alloy wire is provided. The binder, dispersant, solvent, lubricant, and curing agent are sequentially added to a reactor and stirred at 90 °C for 40 min to obtain the coating.

[0046] Embodiment 2

[0047] This embodiment provides a drawing-resistant coating for titanium alloy wire. By weight, the raw materials for preparing the coating include 30 parts of binder, 20 parts of lubricant, 20 parts of solvent, 2 parts of dispersant, and 3 parts of curing agent.

[0048] The specific sources of raw materials in this example are the same as those in Example 1.

[0049] Example 3

[0050] This example provides a draw-resistant coating for titanium alloy wire. By weight, the raw materials for preparing the coating include 50 parts of binder, 40 parts of lubricant, 30 parts of solvent, 5 parts of dispersant, and 8 parts of curing agent.

[0051] The specific sources of raw materials in this example are the same as those in Example 1.

[0052] Example 4

[0053] This example provides a draw-resistant coating for titanium alloy wire. The specific implementation method is the same as that in Example 1. The difference from Example 1 is that the binder is epoxy resin E51 and polyacrylic resin with a mass ratio of 2:1.

[0054] Example 5

[0055] This example provides a draw-resistant coating for titanium alloy wire. The specific implementation method is the same as that in Example 1. The difference from Example 1 is that the solvent is butyl acetate, isobutanol, and ethylene glycol monobutyl ether with a mass ratio of 3:3:3.

[0056] Comparative Example 1

[0057] This example provides a draw-resistant coating for titanium alloy wire. The specific implementation method is the same as that in Example 1. The difference from Example 1 is that the binder is epoxy resin E51 with a mass ratio.

[0058] Comparative Example 2

[0059] This example provides a draw-resistant coating for titanium alloy wire. The specific implementation method is the same as that in Example 1. The difference from Example 1 is that the binder is epoxy resin E51 and polyacrylic resin with a mass ratio of 1:1.

[0060] Comparative Example 3

[0061] This example provides a draw-resistant coating for titanium alloy wire. The specific implementation method is the same as that in Example 1. The difference from Example 1 is that the solvent is butyl acetate, isobutanol, and ethylene glycol monobutyl ether with a mass ratio of 3:6:3.

[0062] Comparative Example 4

[0063] This example provides a draw-resistant coating for titanium alloy wire. The specific implementation method is the same as that in Example 1. The difference from Example 1 is that the dispersant is polyethylene glycol 400.

[0064] Comparative Example 5

[0065] This embodiment provides a draw-resistant coating for titanium alloy wire. The specific implementation method is the same as that of Embodiment 1, and the difference from Embodiment 1 is that the curing agent is dapsone.

[0066] Comparative Example 6

[0067] This embodiment provides a draw-resistant coating for titanium alloy wire. The specific implementation method is the same as that of Embodiment 1, and the difference from Embodiment 1 is that the curing agent is methylhexahydrophthalic anhydride.

[0068] Performance Test

[0069] 1. Spraying Effect Test

[0070] The coatings of Embodiments 1-5 and Comparative Examples 1-6 were applied to the surface of titanium alloy wire by electrostatic spraying. The sample wires were cleaned, placed into the electrostatic spraying chamber, sprayed with the prepared coating, and then sent into the oven for coating curing. The coating thickness was 8-10 μm, and the coating was considered qualified if it was visually observed to be evenly coated.

[0071] 2. Curing Effect Test

[0072] The coatings of Embodiments 1-5 were applied to the surface of titanium alloy wire. The coating thickness was 8-10 μm, and the curing effect test was carried out. It was measured that the initial drying temperature of the coating was 50-70 °C, the curing temperature was 180 °C, and the curing time was 10-15 min. The coating on the surface of the wire was dense and complete, with a dark gray color, and there was no residue when touched by hand.

[0073]

[0074] 3. Adhesion Test:

[0075] The adhesion of the coatings was tested according to GB / T 9286-1998 "Cross-Cut Test for Paints and Varnishes". The coatings of Embodiments 1-5 and Comparative Examples 1-6 were subjected to the adhesion test, and the measured results are shown in Table 1.

[0076] 4. Draw-Resistant Effect Test

[0077] The coated wire samples of Embodiments 1-5 and Comparative Examples 1-6 were directly drawn using an eye die with a reduction ratio of 10-20%. If they could pass the drawing smoothly and the coating on the surface of the wire sample was intact, it was considered qualified. If there were phenomena such as coating peeling, white exposure, and scratching on the surface of the wire sample after drawing, it was considered unqualified.

[0078] The coatings of Embodiments 1-5 and Comparative Examples 1-6 were subjected to the above performance tests. The measured results are shown in Table 1 below.

[0078] Table 1

[0079] Example Adhesion strength Pull-out resistance effect test Spraying effect Example 1 Grade 0 Qualified Qualified Example 2 Grade 0 edge Qualified Qualified Example 3 Grade 0 edge Qualified Qualified Example 4 Grade 1 Qualified Qualified Example 5 Grade 1 Qualified Qualified Comparative example 1 Grade 1 Unqualified Qualified Comparative example 2 Grade 2 Unqualified Qualified Comparative example 3 Grade 2 Unqualified Qualified Comparative example 4 Grade 1 Unqualified Qualified Comparative example 5 Grade 2 Unqualified Qualified Comparative example 6 Grade 1 Unqualified Qualified

Claims

1. A draw-resistant coating for titanium alloy wire, characterized in that, By weight, the raw materials for preparing the coating include 30 - 50 parts of binder, 20 - 40 parts of lubricant, 20 - 30 parts of solvent, 2 - 5 parts of dispersant, and 3 - 8 parts of curing agent; The binder is epoxy resin and acrylic resin; the mass ratio of the epoxy resin to the acrylic resin is 2 - 5:1; the epoxy equivalent of the epoxy resin is 100 - 250 g / eq, and the viscosity at 40 °C is 1000 - 2500 mPa·s; the acrylic resin is polyacrylic acid, and the weight-average molecular weight of the polyacrylic acid is 500 - 5000; The lubricant is molybdenum disulfide, and the particle size of the molybdenum disulfide is 1 - 100 μm; The solvent is butyl acetate, isobutanol, ethylene glycol monobutyl ether; the mass ratio of butyl acetate, isobutanol, and ethylene glycol monobutyl ether is 3 - 5:3 - 5:3; The curing agent is amine curing agent and acid anhydride curing agent, and the mass ratio of the amine curing agent to the acid anhydride curing agent is 1:4 - 6; the amine curing agent is dapsone, and the acid anhydride curing agent is methylhexahydrophthalic anhydride; The dispersant is polyethylene glycol and polyvinyl butyral, and the mass ratio is 8 - 10:1, and the polyethylene glycol is polyethylene glycol 400.

2. The preparation method of the draw-resistant coating for titanium alloy wire according to claim 1, wherein The specific steps are as follows: Add the binder, dispersant, solvent, lubricant, and curing agent into the reactor in sequence and mix evenly to obtain.

3. The application of the pull-resistant coating according to claim 1 in the production and treatment of titanium alloy wire.

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