Wear-resistant coating for machine tool cutter and preparation method of wear-resistant coating

Abstract

The invention discloses a wear-resistant coating for a machine tool cutter. The wear-resistant coating comprises the following components in parts by weight: 2-5 parts of modified nano silicon carbide, 15-25 parts of modified inorganic silica sol, 30-40 parts of cardanol modified epoxy resin, 2-4 parts of modified montmorillonite, 2-4 parts of titanium dioxide, 0.5-1.0 part of a defoaming agent, 0.5-1.5 parts of a dispersing agent, 0.4-0.8 part of a dipropylene glycol butyl ether coalescing agent and 4-8 parts of deionized water. The preparation method comprises the following steps: mixing modified inorganic silica sol, modified montmorillonite and deionized water, carrying out ultrasonic treatment, adding cardanol modified epoxy resin, and stirring to obtain a premix; adding modified nano silicon carbide and titanium dioxide into the premix, dispersing at a high speed, and performing ultrasonic treatment; and adding a defoaming agent, a dispersing agent and a coalescing agent, and stirring to obtain the wear-resistant coating.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coating, in particular to a machine tool cutter wear-resistant coating and a preparation method thereof. BACKGROUND

[0002] Machine tool cutter is the core tool of machining, and its wear resistance directly determines the machining efficiency, workpiece precision and cutter service life. With the increasing demand for difficult-to-machine materials such as titanium alloy, high-temperature alloy and composite material in the fields of aerospace and automobile manufacturing, traditional cutters (such as uncoated cemented carbide and high-speed steel cutters) cannot meet the requirements of high-speed, high-efficiency and high-precision cutting, so it is necessary to improve the performance of cutters by coating wear-resistant coatings on the surface. The cutter faces multiple challenges such as high temperature (800-1000℃), high friction and microbial corrosion (bacteria breeding caused by long-term storage or coolant pollution) during cutting. The wear resistance of the coating is related to the hardness and toughness of the coating, and the coating with high hardness and high toughness often has good wear resistance.

[0003] Although the traditional wear-resistant coating (such as TiAlN and AlCrN) has certain hardness, when the cutting temperature exceeds 700℃, the TiAlN coating is easily oxidized to form a loose Al2O3 layer, resulting in a sharp drop in coating hardness and an accelerated wear rate, which makes it difficult to adapt to high-speed cutting of materials such as titanium alloy and high-temperature alloy. In addition, under intermittent cutting or impact load, cracks may easily propagate, leading to coating peeling and other problems. Moreover, the coating lacks antibacterial and flame-retardant functions, and the cutter may be easily corroded by bacteria during long-term storage, leading to coating peeling. If the cutter comes into contact with flammable coolant or debris during machining, there is a risk of fire. The existing antibacterial coatings are mostly organic materials, which lack wear resistance and high-temperature stability, and cannot adapt to high-speed cutting conditions. Therefore, the existing cutter wear-resistant coatings still have shortcomings in the synergistic improvement of high-temperature stability, hardness, toughness and bonding strength.

[0004] Therefore, there is an urgent need to develop a new type of wear-resistant cutter coating with high hardness, excellent high-temperature stability and strong bonding force, as well as an efficient preparation method thereof. SUMMARY

[0005] The present application aims to provide a machine tool cutter wear-resistant coating and a preparation method thereof to solve the problem of the synergistic improvement of high-temperature stability, hardness, toughness and bonding strength of the existing cutter wear-resistant coating as mentioned in the background.

[0006] In a first aspect, the present application provides a machine tool wear-resistant coating, comprising the following components by weight: 2-5 parts of modified nano silicon carbide, 15-25 parts of modified inorganic silica sol, 30-40 parts of cashew phenol modified epoxy resin, 2-4 parts of modified montmorillonite, 2-4 parts of titanium white, 0.5-1.0 parts of BYK-066N defoamer, 0.5-1.5 parts of BYK-163 dispersant, 0.4-0.8 parts of dipropylene glycol butyl ether film-forming aid, and 4-8 parts of deionized water.

[0007] As a preferred technical solution of the present application, the preparation method of the modified nano silicon carbide is as follows: nano silicon carbide with an average particle size of 50-80 nm is added into a mixed solution of ethanol and water, then 1-3% silane coupling agent KH-570 by mass of the nano silicon carbide is added, stirring and reaction is carried out at 60-80℃ for 2-3h, then centrifugation is carried out at 3000-5000rpm for 10-20min, the supernatant is discarded, and the bottom precipitate is placed in a drying oven and dried at 60-80℃ for 1-2h to obtain the modified nano silicon carbide. The mass ratio of ethanol to water is 2-3:1, and the mass ratio of the mixed solution of ethanol and water to nano silicon carbide is 1:15-17.

[0008] As a preferred technical solution of the present application, the preparation method of the modified inorganic silica sol is as follows: S1. 45-50 parts by weight of tetraethyl orthosilicate, 15-20 parts by weight of silane coupling agent KH-560, and 98-100 parts by weight of anhydrous ethanol are mixed, stirring is carried out in a 60℃ water bath, a catalytic solution is added, and stirring reaction is continued for 4-4.5h to obtain a silica sol base solution; S2. 5-10 parts by weight of nano diamond, 3-5 parts by weight of nano zirconium dioxide, and 2-3 parts by weight of nano aluminum oxide are added to the silica sol base solution, 0.5-1.5 parts by weight of dispersant BYK-163 is added, then ultrasonic dispersion is carried out in an ultrasonic device to obtain a uniform and stable modified inorganic silica sol.

[0009] As a preferred technical solution of the present application, the stirring rate in S1 is 200-300rpm; the catalytic solution is composed of 0.1-0.2mol / L hydrochloric acid and deionized water in a mass ratio of 1:3, and the addition amount of the catalytic solution is 0.5-1% of the mass of the silane coupling agent KH-560.

[0010] As a preferred technical solution of the present application, the particle size of the nano diamond in S2 is 20-50nm, the particle size of the nano zirconium dioxide is 30-50nm, and the particle size of the nano aluminum oxide is 20-40nm; the power of the ultrasonic device is 900-1000W, and the ultrasonic time is 1-1.5h.

[0011] As a preferred technical scheme of the present application, the preparation method of the cardanol-modified epoxy resin is as follows: cardanol and epichlorohydrin are mixed at a molar ratio of 1:1.2~1.5, a 30% NaOH solution is added, then the mixture is reacted at 75~85℃ for 3~5h, excess epichlorohydrin is removed by vacuum distillation, the mixture is cooled to room temperature and washed with anhydrous ethanol for 3~5 times, and then the cardanol-modified epoxy resin is obtained after drying; As a preferred technical scheme of the present application, the amount of the 30% NaOH solution added is 20~30% of the mass of the cardanol; The vacuum degree of the vacuum distillation is 0.08~0.1MPa, the distillation temperature is 50~70℃, and the time is 2~4h; The drying temperature is 60~80℃, and the time is 2~3h.

[0012] As a preferred technical scheme of the present application, the preparation method of the modified montmorillonite is as follows: montmorillonite and deionized water are mixed at a solid-liquid ratio of 1:20~30, and then dispersed by using an ultrasonic device, wherein the ultrasonic power of the ultrasonic device is 500~800W, and the ultrasonic time is 30~45min, then 5~8% of the silane coupling agent KH-560 by mass of the montmorillonite is added, and the mixture is stirred and reacted at 70~80℃ for 2~3h, then centrifuged at 5000~5500rpm for 15~20min, the supernatant is discarded, and the bottom precipitate is placed in a drying oven and dried at 50~60℃ for 2~2.5h to obtain the modified montmorillonite.

[0013] In a second aspect, the present application further provides a preparation method of a wear-resistant coating for machine tool cutters, which comprises the following steps: S1. Pre-mixing, mixing the modified inorganic silica sol, the modified montmorillonite and deionized water, and then ultrasonicating at 200~300W for 8~10min, then adding the cardanol-modified epoxy resin, and stirring at 35℃ for 8~10min to obtain a pre-mixed mixture; S2. Dispersing the reinforcing phase, adding the modified nano-silicon carbide and titanium white powder to the pre-mixed mixture, and dispersing at a speed of 3000~4000rpm for 25~30min, and then ultrasonicating at a power of 300~400W for 8~10min; S3. Adding additives, adding the BYK-066N defoaming agent, the BYK-163 dispersing agent and the dipropylene glycol butyl ether film-forming aid, and stirring at a speed of 500~800rpm at 30~32℃ for 10~12min to obtain the wear-resistant coating.

[0014] Compared with the prior art, the present application has the following advantages: 1. This invention, through targeted modification design, constructs a dual interfacial bonding mechanism of "chemical bonding + physical anchoring," achieving a leap in interfacial strength. By modifying nano-silicon carbide with the silane coupling agent KH-570 (containing methacryloxy group), the siloxy groups of KH-570 can react with the hydroxyl groups on the silicon carbide surface to form covalent bonds, while the double bonds can chemically react with the epoxy groups in the cashew phenol-modified epoxy resin. This allows the inorganic particles to be tightly connected to the organic matrix through "chemical bonding." Simultaneously, this modification forms Si-OC bonds on the surface of nano-silicon carbide, significantly improving its dispersibility in the resin matrix and avoiding performance degradation caused by agglomeration. In the preparation of modified montmorillonite, the layered structure is first ultrasonically exfoliated, and then KH-560 modification (containing epoxy group) is introduced. This not only inserts into the interlayer space of montmorillonite to expand the interlayer spacing but also undergoes a ring-opening reaction with the hydroxyl groups of the epoxy resin, forming a "network cross-linked" interface between the montmorillonite sheets and the matrix, which enhances mechanical properties and inhibits crack propagation.

[0015] 2. In this invention, the inorganic silica sol is modified with silane coupling agent KH-560 and a ternary system of nano-diamond, nano-zirconium dioxide, and nano-alumina hard particles is introduced. Nano-diamond acts as "hard particles" to improve the wear resistance of the coating surface; nano-zirconium dioxide inhibits oxidative wear during high-temperature cutting; and nano-alumina alleviates stress concentration during impact, reducing the risk of brittle fracture. The three types of nanoparticles achieve dense filling through a particle size gradient, significantly reducing porosity compared to traditional single-particle systems, thus significantly improving wear life. Furthermore, it greatly enhances the coating's hardness and wear resistance, making it suitable for high-wear cutting tool conditions. It also enhances compatibility with other components, preventing delamination, while improving the adhesion between the coating and the tool substrate, reducing peeling, and imparting good high-temperature resistance to cope with cutting temperature rises.

[0016] 3. In this invention, the cashew phenol-modified epoxy resin possesses both strong adhesion and toughness. It retains the strong bonding ability of epoxy resin to various fillers, ensuring the integrity of the coating, while the long alkyl chain of cashew phenol improves the brittleness of pure epoxy resin, reducing cracking caused by cutting vibration. The cashew phenol raw material is naturally sourced, offering both environmental and cost advantages. Furthermore, after modification, it exhibits good compatibility with other components, contributing to the formation of a uniform coating and synergistically enhancing the wear resistance and impact resistance of the modified inorganic silica sol. In addition, the cashew phenol-modified epoxy resin (organic phase) and the modified inorganic silica sol (inorganic phase) form an interpenetrating network structure. The epoxy resin provides flexibility and adhesion, while the silica sol forms an inorganic skeleton to increase hardness. Together, they achieve a "hard but not brittle" result.

[0017] 4、The present application realizes "efficient preparation + stable performance" by step-by-step dispersion, and innovatively adopts the sequence of "first ultrasonic dispersion of inorganic phase, and then mixing with organic phase". The montmorillonite layers are fully peeled off and uniformly dispersed in the silica sol through ultrasonic treatment, avoiding agglomeration caused by sudden increase in viscosity when directly mixed with the resin. The initial agglomeration of the particles is broken by mechanical dispersion during the dispersion of the reinforcing phase, and the ultrasonic treatment realizes nanoscale dispersion through cavitation effect, so that the dispersion particle size of the modified nanoscale silicon carbide and titanium white powder is controlled within 100 nm, the total dispersion time is shortened, and the energy consumption is reduced. When the additives are added, low-speed stirring at low temperature is adopted, which not only avoids the failure of the additives caused by high temperature, but also reduces the introduction of new bubbles, ensuring that the coating has no pinholes and shrinkage. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The preparation flow chart of the machine tool tool wear-resistant coating of the present application. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0020] Nanoscale silicon carbide (SiC) itself has high hardness, high wear resistance and high temperature resistance, and is an ideal wear-resistant reinforcing phase. However, unmodified nanoscale silicon carbide has strong surface polarity, is easy to agglomerate, and has poor compatibility with the organic matrix, so it is difficult to play a role. After modification, the siloxane groups of KH-570 react with the hydroxyl groups on the surface of silicon carbide to form covalent bonds, and the methacryloyloxy groups (containing double bonds) at the other end can chemically react with the epoxy groups in the cashew phenol modified epoxy resin, realizing the chemical bonding of "inorganic particles-organic matrix".

[0021] Montmorillonite is a layered silicate mineral. When unmodified, the interlayer force is strong, and it is difficult to play a reinforcing role. Moreover, sodium ions exist between the layers, the interlayer distance is small, and the surface is hydrophilic, so it has poor compatibility with the hydrophobic organic matrix and is easy to agglomerate into blocks. The ultrasonic cavitation effect is used to break the interlayer force, so that the interlayer distance is expanded. Then, the silane coupling agent KH-560 (containing epoxy groups) is introduced, which not only inserts into the interlayer of montmorillonite to further expand the layers, but also reacts with the hydroxyl groups of the cashew phenol modified epoxy resin through ring-opening reaction, realizing the chemical bonding of "montmorillonite layer-organic matrix", so that the montmorillonite is uniformly dispersed in the coating in the form of "single layer", forming a three-dimensional nanoscale reinforcing network.

[0022] Cardanol is derived from cashew nut shell liquid (a natural renewable resource), rather than the traditional epoxy resin relying on petroleum-based raw materials. The long-chain alkyl group (-C 15 H 31 ) with 15 carbons in the cardanol molecule will be embedded in the molecular chain of epoxy resin after chemical modification, which is equivalent to introducing "flexible segments" into the rigid epoxy backbone. This structure allows the coating to relieve stress concentration through rotation and sliding of long-chain alkyl groups when stressed (such as impact during cutting), significantly improving impact strength and preventing brittle cracking and peeling. At the same time, the phenolic hydroxyl group of cardanol can react with the epoxy group of epoxy resin to form a more dense crosslinking network, retaining the original high adhesion and chemical resistance of epoxy resin, ensuring that the coating does not peel off or degrade under cutting fluid immersion. In the modified epoxy resin molecule, in addition to retaining the epoxy group (which can react with the hydroxyl and amino groups on the surface of inorganic phases), the long-chain alkyl group of cardanol can also form "physical anchoring" with the organic modified groups on the surface of montmorillonite layers and nanoparticles through van der Waals forces, reducing interfacial voids. This dual action of "chemical bonding + physical anchoring" allows inorganic particles to disperse more uniformly in the organic matrix, avoiding local stress concentration caused by uneven dispersion and thus improving the overall wear resistance of the coating.

[0023] Inorganic silica sol is modified by silane coupling agent KH-560 and introduced into a ternary system of nano-diamond, nano-zirconia, and nano-alumina hard particles. Nano-diamond acts as a "hard point" to improve the surface wear resistance of the coating, nano-zirconia inhibits oxidation wear at high temperature cutting, and nano-alumina relieves stress concentration and reduces the risk of brittle fracture when the coating is impacted. The three types of nanoparticles are densely packed through a particle size gradient, resulting in a significant reduction in porosity compared to traditional single-particle systems, significantly improving wear life. In addition, it also significantly improves the hardness and wear resistance of the coating, adapts to high wear conditions of the tool, enhances the compatibility with other components, avoids delamination, improves the adhesion of the coating to the tool substrate, reduces peeling, and endows the coating with good high-temperature resistance to cope with cutting temperature rise.

[0024] For example Figure 1As shown, a method for preparing a machine tool cutter wear-resistant coating comprises the following steps: S1. Pre-mixing, mixing modified inorganic silica sol, modified montmorillonite and deionized water, ultrasonic 8-10 min under 200-300 W, then adding cashew phenol modified epoxy resin, stirring 8-10 min at 35℃, obtaining a pre-mixed mixture. S2. Strengthening phase dispersion, adding modified nano silicon carbide and titanium dioxide to the pre-mixed mixture, dispersing at a speed of 3000-4000 rpm for 25-30 min, and then ultrasonic dispersing at a power of 300-400 W for 8-10 min. S3. Additives, add BYK-066N defoamer, BYK-163 dispersant and dipropylene glycol butyl ether film forming aid, stir at a speed of 500-800 rpm for 10-12 min at 30-32℃ to obtain a wear-resistant coating.

[0025] The raw materials used in the present application are all commercially available.

[0026] Example one:

[0027] A machine tool cutter wear-resistant coating comprises the following components by weight: modified nano silicon carbide 5 parts, modified inorganic silica sol 25 parts, cashew phenol modified epoxy resin 40 parts, modified montmorillonite 4 parts, titanium dioxide 4 parts, BYK-066N defoamer 1 part, BYK-163 dispersant 1.5 parts, dipropylene glycol butyl ether film forming aid 0.8 parts, deionized water 8 parts.

[0028] The modified nano silicon carbide is prepared by the following method: take nano silicon carbide with an average particle size of 80 nm and add it to a mixture of ethanol and water (the mass ratio of ethanol to water is 3:1, and the mass ratio of the mixture of ethanol and water to nano silicon carbide is 1:17), then add 3% silane coupling agent KH-570 of the mass of nano silicon carbide, stir and react at 80℃ for 3h, then centrifuge at 5000rpm for 20min, discard the supernatant, and place the bottom precipitate in a drying oven at 80℃ for 2h to obtain modified nano silicon carbide.

[0029] The modified inorganic silica sol is prepared by the following method: S1. 50 parts by weight of tetraethyl orthosilicate, 20 parts by weight of silane coupling agent KH-560 and 100 parts by weight of anhydrous ethanol are mixed, stirred at 300 rpm in a 60°C water bath, and a catalyst solution (consisting of 0.2 mol / L hydrochloric acid and deionized water in a mass ratio of 1:3, added in an amount of 1% of the mass of the silane coupling agent KH-560) is added, and stirring is continued at 300 rpm for 4.5 h to obtain a silica sol base solution. S2. 6 parts by weight of nanodiamond (particle size 20-50 nm), 5 parts by weight of nanometer zirconium dioxide (particle size 30-50 nm) and 3 parts by weight of nanometer alumina (particle size 20-40 nm) are added to the silica sol base solution, and 1.5 parts by weight of dispersant BYK-163 is added, and then ultrasonic dispersion is carried out in an ultrasonic device for 1.5 h, and the power of the ultrasonic device is 1000 W, and then a uniform and stable modified inorganic silica sol is obtained.

[0030] The cashew phenol modified epoxy resin is prepared by the following method: cashew phenol and epichlorohydrin are mixed in a molar ratio of 1:1.5, a 30% NaOH solution (added in an amount of 30% of the mass of cashew phenol) is added, and then reacted at 85°C for 5 h, the excess epichlorohydrin is removed by reduced pressure distillation (vacuum degree 0.1 MPa, distillation temperature 70°C, time 4 h), and after cooling to room temperature, washed with anhydrous ethanol 5 times, and dried at 80°C for 3 h to obtain the cashew phenol modified epoxy resin.

[0031] The modified montmorillonite is prepared by the following method: montmorillonite and deionized water are mixed in a solid-liquid ratio of 1:30, dispersed using an ultrasonic device, wherein the ultrasonic power of the ultrasonic device is 800 W and the ultrasonic time is 45 min, then 8% silane coupling agent KH-560 of the mass of the montmorillonite is added, stirred and reacted at 80°C for 3 h, then centrifuged at 5500 rpm for 20 min, the supernatant is discarded, and the bottom sediment is placed in a drying oven and dried at 60°C for 2.5 h to obtain the modified montmorillonite.

[0032] A preparation method of a machine tool tool wear-resistant coating, comprising the following steps: S1. Pre-mixing, mixing the modified inorganic silica sol, the modified montmorillonite and deionized water, ultrasonic dispersion at 300 W for 10 min, then adding the cashew phenol modified epoxy resin, stirring at 35°C for 10 min to obtain a pre-mixed mixture; S2. Dispersing the reinforcing phase, adding the modified nanometer silicon carbide and titanium white powder to the pre-mixed mixture, dispersing at a speed of 4000 rpm for 30 min, and then ultrasonic dispersing at a power of 400 W for 10 min; S3. Additives were added, BYK-066N defoaming agent, BYK-163 dispersant and dipropylene glycol butyl ether film forming agent, and the abrasion resistant coating was obtained after stirring at 32℃ for 12min at 800rpm.

[0033] Example two:

[0034] An abrasion resistant coating for machine tool cutters, comprising the following components by weight: 2 parts of modified nano silicon carbide, 15 parts of modified inorganic silica sol, 30 parts of cardanol modified epoxy resin, 2 parts of modified montmorillonite, 2 parts of titanium white, 0.5 parts of BYK-066N defoaming agent, 0.5 parts of BYK-163 dispersant, 0.4 parts of dipropylene glycol butyl ether film forming agent, and 4 parts of deionized water.

[0035] The modified nano silicon carbide was prepared as follows: nano silicon carbide with an average particle size of 50nm was added to a mixture of ethanol and water (mass ratio of ethanol to water was 2:1, mass ratio of the mixture of ethanol and water to nano silicon carbide was 1:15), then 1% silane coupling agent KH-570 by mass of nano silicon carbide was added, stirred and reacted at 60℃ for 2h, then centrifuged at 3000rpm for 10min, the supernatant was discarded, and the bottom sediment was placed in a drying oven and dried at 60℃ for 1h to obtain modified nano silicon carbide.

[0036] The modified inorganic silica sol was prepared as follows: S1. 45 parts by weight of tetraethyl orthosilicate, 15 parts by weight of silane coupling agent KH-560 and 98 parts by weight of anhydrous ethanol were mixed, stirred at 200rpm in a 60℃ water bath, and a catalytic solution (consisting of 0.1mol / L hydrochloric acid and deionized water in a mass ratio of 1:3, added amount was 0.5% of the mass of silane coupling agent KH-560) was added, and the stirring was continued at 200rpm for 4h to obtain a silica sol base solution. S2. 3 parts by weight of nano diamond (particle size 20-50nm), 3 parts by weight of nano zirconium dioxide (particle size 30-50nm) and 2 parts by weight of nano alumina (particle size 20-40nm) were added to the silica sol base solution, and 0.5 parts by weight of dispersant BYK-163 was added, then ultrasonic dispersion was carried out in an ultrasonic device for 1h, and the power of the ultrasonic device was 900W, then a uniform and stable modified inorganic silica sol was obtained.

[0037] The cardanol modified epoxy resin was prepared as follows: cardanol and epichlorohydrin were mixed in a molar ratio of 1:1.2, 30% NaOH solution (added amount was 20% of the mass of cardanol) was added, then reacted at 75℃ for 3h, excess epichlorohydrin was removed by vacuum distillation (vacuum degree was 0.08MPa, distillation temperature was 50℃, time was 2h), cooled to room temperature, washed with anhydrous ethanol for 3 times, dried at 60℃ for 2h to obtain cardanol modified epoxy resin.

[0038] The modified montmorillonite is prepared by the following method: montmorillonite is mixed with deionized water at a solid-liquid ratio of 1:20, and an ultrasonic device is used for dispersion, wherein the ultrasonic power of the ultrasonic device is 500 W, and the ultrasonic time is 30 min, then 5% silane coupling agent KH-560 by mass of the montmorillonite is added, stirring and reacting at 70℃ for 2 h, then centrifuging at 5000 rpm for 15 min, discarding the supernatant, and placing the bottom precipitate in a drying oven, drying at 50℃ for 2 h to obtain the modified montmorillonite.

[0039] A preparation method of a machine tool tool wear-resistant coating, comprising the following steps: S1. Pre-mixing, mixing modified inorganic silica sol, modified montmorillonite and deionized water, ultrasonic at 200 W for 8 min, then adding cashew phenol modified epoxy resin, stirring at 35℃ for 8 min to obtain a pre-mixed mixture; S2. Dispersing the reinforcing phase, adding modified nano silicon carbide and titanium dioxide to the pre-mixed mixture, dispersing at a speed of 3000 rpm for 25 min, then ultrasonic dispersing at a power of 300 W for 8 min; S3. Additives, add BYK-066N defoamer, BYK-163 dispersant and dipropylene glycol butyl ether film forming aid, stir at a speed of 500 rpm at 30℃ for 10 min to obtain the wear-resistant coating.

[0040] Example three:

[0041] A machine tool tool wear-resistant coating, comprising the following components by weight: modified nano silicon carbide 3 parts, modified inorganic silica sol 20 parts, cashew phenol modified epoxy resin 35 parts, modified montmorillonite 3 parts, titanium dioxide 3 parts, BYK-066N defoamer 0.7 parts, BYK-163 dispersant 1 part, dipropylene glycol butyl ether film forming aid 0.6 parts, deionized water 6 parts.

[0042] The modified nano silicon carbide is prepared by the following method: nano silicon carbide with an average particle size of 80 nm is added to a mixture of ethanol and water (the mass ratio of ethanol to water is 2.5:1, and the mass ratio of the mixture of ethanol and water to nano silicon carbide is 1:16), then 2% silane coupling agent KH-570 by mass of the nano silicon carbide is added, stirring and reacting at 70℃ for 2.5 h, then centrifuging at 4000 rpm for 15 min, discarding the supernatant, and placing the bottom precipitate in a drying oven, drying at 70℃ for 1.5 h to obtain the modified nano silicon carbide.

[0043] The modified inorganic silica sol is prepared by the following method: S1. 47 parts by weight of tetraethyl orthosilicate, 17 parts by weight of silane coupling agent KH-560 and 99 parts by weight of anhydrous ethanol are mixed, stirred at a speed of 250 rpm in a water bath at 60°C, and a catalytic liquid (consisting of 0.15 mol / L hydrochloric acid and deionized water in a mass ratio of 1:3, and the addition amount is 0.7% of the mass of the silane coupling agent KH-560) is added, and the stirring is continued at a speed of 250 rpm for 4.2 hours to obtain a silica sol base solution. S2. 5 parts by weight of nano diamond (particle size of 20-50 nm), 4 parts by weight of nano zirconium dioxide (particle size of 30-50 nm) and 2.5 parts by weight of nano alumina (particle size of 20-40 nm) are added to the silica sol base solution, and 1 part by weight of dispersant BYK-163 is added, and then ultrasonic dispersion is carried out in an ultrasonic device for 1.2 hours, and the power of the ultrasonic device is 950W, and then a uniform and stable modified inorganic silica sol is obtained.

[0044] The cardanol-modified epoxy resin is prepared by the following method: cardanol and epichlorohydrin are mixed in a molar ratio of 1:1.3, a 30% NaOH solution (the addition amount is 25% of the mass of cardanol) is added, and then the mixture is reacted at 80°C for 4 hours. The excess epichlorohydrin is removed by vacuum distillation (vacuum degree is 0.09 MPa, distillation temperature is 60°C, and time is 3 hours). After cooling to room temperature, the mixture is washed with anhydrous ethanol for 4 times. The cardanol-modified epoxy resin is obtained after drying at 70°C for 2.5 hours.

[0045] The modified montmorillonite is prepared by the following method: montmorillonite and deionized water are mixed in a solid-liquid ratio of 1:25, and dispersed using an ultrasonic device, wherein the ultrasonic power of the ultrasonic device is 650W, and the ultrasonic time is 37min. Then, 6.5% of the mass of the montmorillonite is added to the mixture as silane coupling agent KH-560, and the mixture is stirred at 75°C for 2.5 hours. Then, the mixture is centrifuged at 5200 rpm for 17 minutes, the supernatant is discarded, and the bottom sediment is placed in a drying oven and dried at 55°C for 2.2 hours to obtain the modified montmorillonite.

[0046] A method for preparing a wear-resistant coating for a machine tool cutter, comprising the following steps: S1. Pre-mixing, mixing the modified inorganic silica sol, the modified montmorillonite and deionized water, ultrasonic dispersion at 250W for 9min, then adding the cardanol-modified epoxy resin, stirring at 35°C for 9min to obtain a pre-mixed mixture; S2. Dispersing the reinforcing phase, adding the modified nano silicon carbide and titanium white powder to the pre-mixed mixture, dispersing at a speed of 3500 rpm for 27min, and then ultrasonic dispersing at a power of 350W for 9min; S3. Additives were added, BYK-066N defoaming agent, BYK-163 dispersant and dipropylene glycol butyl ether film forming aid, and the anti-wear coating was obtained after stirring at 31℃ for 11 min at a rotation speed of 650 rpm.

[0047] Comparative Example 1: The difference from Example 1 is that polyurethane is used instead of cardanol-modified epoxy resin.

[0048] Comparative Example 2: The difference from Example 1 is that the modified inorganic silica sol is removed.

[0049] Comparative Example 3: The difference from Example 1 is that the silicon carbide is directly added without modification.

[0050] Comparative Example 4: The difference from Example 1 is that the montmorillonite is directly added without modification.

[0051] The anti-wear coatings prepared in Examples 1, 2, 3 and Comparative Examples 1, 2, 3 and 4 were tested for performance.

[0052] The anti-wear coatings prepared in Examples 1, 2, 3 and Comparative Examples 1, 2, 3 and 4 were tested for performance.

[0053] Table 1: Measurement of related indexes of anti-wear coatings prepared in Examples and Comparative Examples

[0054] From the table, it can be seen that the anti-wear coatings prepared in the examples of the present application are significantly higher in high-temperature oxidation resistance, hardness and bonding strength than the comparative examples, and also have good flame retardation effect and wear resistance.

[0055] The long-chain aliphatic hydrocarbon structure of the cashew phenol modified epoxy resin as a coating matrix endows the coating with excellent flexibility and internal plasticizing effect, effectively alleviates the curing stress, thereby significantly improving the bonding strength of the coating and the tool substrate, avoids the peeling problem caused by insufficient adhesion, and simultaneously, the phenolic ring structure and crosslinked network in the molecule provide excellent high-temperature oxidation resistance, so that the coating can maintain structural integrity and is not easy to decompose and fail at high temperature generated by high-speed cutting. The modified inorganic silica sol (loaded with nanometer diamond, zirconium dioxide and alumina) forms a solid inorganic skeleton network during the curing process, greatly improving the hardness and wear resistance of the coating. The nanometer diamond provides superhard points, the nanometer zirconium dioxide inhibits crack propagation through the phase change toughening mechanism, and the nanometer alumina further enhances the high-temperature stability and anti-creep ability of the coating. The inorganic phase and the organic resin phase are combined to form a synergistic organic-inorganic interpenetrating network, which is the key to the high hardness and toughness of the coating. Meanwhile, the SiO2 inorganic skeleton formed by the modified inorganic silica sol can block oxygen, and the modified silicon carbide with high temperature resistance can inhibit the oxidative degradation of the coating at high temperature. After removing the silica sol, the coating is easy to heat deform. The modified nanometer silicon carbide and the modified montmorillonite are the core reinforcing phase. The KH-570 modification enables the nanometer silicon carbide to be uniformly dispersed in the system, and its high hardness directly contributes to the wear resistance. The modified montmorillonite is treated by silane coupling agent, and the layered structure is partially exfoliated in the system. Not only can it effectively improve the flame retardation effect of the coating, but also can delay thermal decomposition and flame propagation by forming a physical barrier, and can also be closely combined with the resin to hinder dislocation movement and crack propagation, further improving the bonding strength, hardness and toughness of the coating. Therefore, the combined action of these surface modified components solves the contradiction between hardness, toughness, bonding force and temperature resistance of traditional coatings.

[0056] In summary, the wear-resistant coating prepared by the present application not only has excellent wear resistance, but also has excellent high-temperature oxidation resistance, high hardness, strong bonding strength and good flame retardation effect.

[0057] The above is only a specific embodiment of the present application, but the technical features of the present application are not limited thereto. Any simple change, equivalent replacement or modification made on the basis of the present application to solve the same technical problem and achieve the same technical effect is covered by the protection scope of the present application.

Claims

1. A wear-resistant coating for machine tool cutting tools, characterized in that, The product comprises the following components in parts by weight: 2-5 parts modified nano-silicon carbide, 15-25 parts modified inorganic silica sol, 30-40 parts cashew phenol modified epoxy resin, 2-4 parts modified montmorillonite, 2-4 parts titanium dioxide, 0.5-1.0 parts BYK-066N defoamer, 0.5-1.5 parts BYK-163 dispersant, 0.4-0.8 parts dipropylene glycol butyl ether film-forming aid, and 4-8 parts deionized water.

2. The wear-resistant coating for machine tool cutting tools according to claim 1, characterized in that, The modified nano-silicon carbide is prepared as follows: nano-silicon carbide with an average particle size of 50-80 nm is added to a mixture of ethanol and water, and then 1-3% of silane coupling agent KH-570 (by mass of nano-silicon carbide) is added. The mixture is stirred at 60-80℃ for 2-3 h, and then centrifuged at 3000-5000 rpm for 10-20 min. The supernatant is discarded, and the bottom precipitate is placed in a drying oven and dried at 60-80℃ for 1-2 h to obtain modified nano-silicon carbide. The mass ratio of ethanol to water in the ethanol-water mixture is 2-3:1, and the mass ratio of the ethanol-water mixture to nano-silicon carbide is 1:15-17.

3. The wear-resistant coating for machine tool cutting tools according to claim 1, characterized in that, The modified inorganic silica sol is prepared by: S1. Mix 45-50 parts by weight of tetraethyl orthosilicate, 15-20 parts by weight of silane coupling agent KH-560 and 98-100 parts by weight of anhydrous ethanol, stir in a water bath at 60°C, add a catalyst solution, and continue stirring for 4-4.5 hours to obtain a silica sol base solution. S2. Add 3-6 parts by weight of nano-diamond, 3-5 parts by weight of nano-zirconia and 2-3 parts by weight of nano-alumina to the silica sol base solution, and add 0.5-1.5 parts by weight of dispersant BYK-163. Then, ultrasonically disperse the solution in an ultrasonic device to obtain a uniform and stable modified inorganic silica sol.

4. The wear-resistant coating for machine tool cutting tools according to claim 3, characterized in that, The stirring speed in S1 is 200-300 rpm; the catalyst solution is composed of 0.1-0.2 mol / L hydrochloric acid and deionized water in a mass ratio of 1:3, and the amount of catalyst solution added is 0.5-1% of the mass of silane coupling agent KH-560.

5. The wear-resistant coating for machine tool cutting tools according to claim 3, characterized in that, The nanodiamond in S2 has a particle size of 20-50 nm, the nanozirconium dioxide has a particle size of 30-50 nm, and the nanoalumina has a particle size of 20-40 nm; the ultrasonic device has a power of 900-1000 W and an ultrasonic time of 1-1.5 h.

6. The wear-resistant coating for machine tool cutting tools according to claim 1, characterized in that, The preparation method of the cashew nut phenol modified epoxy resin is as follows: cashew nut phenol and epichlorohydrin are mixed at a molar ratio of 1:1.2~1.5, and a 30% NaOH solution is added. The mixture is then reacted at 75~85℃ for 3~5 hours. Excess epichlorohydrin is removed by vacuum distillation. After cooling to room temperature, the mixture is washed 3~5 times with anhydrous ethanol and dried at 60~80℃ for 2~3 hours to obtain the cashew nut phenol modified epoxy resin.

7. The wear-resistant coating for machine tool cutting tools according to claim 6, characterized in that: The amount of the 30% NaOH solution added is 20-30% of the mass of cashew phenol; The vacuum degree of the vacuum distillation is 0.08~0.1MPa, the distillation temperature is 50~70℃, and the time is 2~4h.

8. The wear-resistant coating for machine tool cutting tools according to claim 1, characterized in that, The modified montmorillonite is prepared as follows: montmorillonite and deionized water are mixed at a solid-liquid ratio of 1:20-30, and dispersed using an ultrasonic device with an ultrasonic power of 500-800W and an ultrasonic time of 30-45min. Then, 5-8% of the mass of montmorillonite as silane coupling agent KH-560 is added, and the mixture is stirred and reacted at 70-80℃ for 2-3h. Afterward, the mixture is centrifuged at 5000-5500rpm for 15-20min, the supernatant is discarded, and the bottom precipitate is placed in a drying oven and dried at 50-60℃ for 2-2.5h to obtain the modified montmorillonite.

9. The method for preparing a wear-resistant coating for machine tool cutting tools according to claim 1, characterized in that, Includes the following steps: S1. Premixing: Modified inorganic silica sol, modified montmorillonite and deionized water are mixed and ultrasonicated at 200~300W for 8~10min. Then cashew phenol modified epoxy resin is added and stirred at 35℃ for 8~10min to obtain a premixed mixture. S2. Enhance phase dispersion: Add modified nano-silicon carbide and titanium dioxide to the premixed mixture, disperse at 3000~4000 rpm for 25~30 min, and then ultrasonically disperse at an ultrasonic power of 300~400W for 8~10 min. S3. Additives: Add BYK-066N defoamer, BYK-163 dispersant and dipropylene glycol butyl ether film-forming aid, and stir at 30~32℃ and 500~800rpm for 10~12min to obtain a wear-resistant coating.

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