High-toughness tungsten carbide nano coating art knife and preparation method thereof

Abstract

The invention discloses a high-toughness tungsten carbide nano-coating art knife and a preparation method thereof, and belongs to the technical field of coated cutters, the high-toughness tungsten carbide nano-coating art knife comprises a blade base body and a nano composite coating arranged on the surface of the blade base body; wherein the nano-composite coating comprises WC, Y, Si, B, C and O, the Y, the Si, the B, the C and the O exist in the nano-composite coating in an amorphous phase form, an sp2 / sp3 mixed hybrid carbon layer is arranged between the blade base body and the nano-composite coating, and the blade base body is made of stainless steel. The high-toughness tungsten carbide nano coating art knife is prepared through blade base body treatment, sp2 / sp3 mixed hybrid carbon layer treatment, nano composite coating treatment and surface repairing treatment, and meanwhile the high-toughness tungsten carbide nano coating art knife has high hardness, high toughness, high binding force and low friction performance; and the technical problems of poor binding force and easy stripping caused by huge physical property difference between the hard coating and the flexible stainless steel substrate are solved.

Description

Technical Field

[0001] This invention relates to the field of coated cutting tool technology, specifically to a high-toughness tungsten carbide nano-coated utility knife and its preparation method. Background Technology

[0002] In modern manufacturing, machining technology is a core foundational process, and its efficiency and quality directly determine the performance and reliability of high-end equipment. Coated cutting tools, as a cutting-edge technology, significantly improve the overall cutting performance, service life, and machining accuracy of cutting tools without sacrificing the toughness of the substrate by depositing one or more layers of thin film materials with high hardness, high wear resistance, chemical stability, and low coefficient of friction on the surface of a tool substrate.

[0003] Despite significant advancements in coating technology, existing techniques still face numerous severe challenges and technical bottlenecks when dealing with difficult-to-machine materials widely used in aerospace, energy, and other fields. Traditional binary nitride coatings, while exhibiting high hardness, are inherently brittle materials, making them highly susceptible to micro-chipping or spalling under the intense impact loads of interrupted cutting or deep-cut machining, leading to catastrophic tool failure. Furthermore, multi-element alloying or multi-layer structures introduced to improve toughness often come at the cost of sacrificing some hardness or high-temperature performance, making it difficult to achieve a perfect balance between the two.

[0004] Reference CN118880264B proposes a method for preparing NbN / CrB2 composite coated cutting tools using high-power pulsed magnetron sputtering. This method reduces internal stress by designing functional layers with gradient thicknesses and utilizes the high-temperature stability of NbN to handle high-temperature alloy machining. While this approach has some innovation, it still has some potential limitations. First, in the functional layers of this invention, the thickness of the NbN and CrB2 sublayers increases with the number of deposition cycles. Although this fine, non-uniform gradient structure can theoretically effectively release stress, in industrial mass production, precisely controlling the constantly changing deposition time within each cycle and ensuring a high degree of consistency in the coating structure of all cutting tools throughout the entire furnace batch places extremely high demands on equipment stability and process control precision. Any slight process fluctuation can lead to significant differences in coating performance, increasing production unreliability. Second, this invention uses pure NbN as the outermost anti-adhesion coating. Although NbN has good high-temperature chemical stability and anti-adhesion properties, Its intrinsic hardness is lower than that of the underlying NbN / CrB2 composite layer and the mainstream TiAlN-based coating. In the early stages of cutting, this relatively soft top layer may be worn away prematurely under strong abrasive wear, thus failing to fully utilize its anti-adhesion advantage and prematurely exposing the underlying functional layer, thereby limiting the overall wear resistance life of the tool. Third, this invention constructs a large number of NbN / CrB2 interfaces. At a deposition temperature as high as 650°C, atoms of different materials may diffuse into each other at the interface or form brittle ternary compounds. These unknown interface phases may become the source of crack initiation, which in turn weakens the overall toughness and bonding strength of the coating. Summary of the Invention

[0005] This invention discloses a high-toughness tungsten carbide nano-coated utility knife and its preparation method, which involves blade substrate treatment and sp... 2 / sp 3 By combining a hybrid carbon layer, a nanocomposite coating, and surface repair treatment, a high-toughness tungsten carbide nanocoated utility knife was prepared. It possesses high hardness, high toughness, high adhesion, and low friction properties, solving the problems of insufficient hardness, easy wear, and short lifespan of traditional utility knife blades in the prior art. At the same time, it overcomes the technical problems of poor adhesion and easy peeling caused by the huge difference in physical properties between the hard coating and the flexible stainless steel substrate.

[0006] This invention protects a high-toughness tungsten carbide nano-coated utility knife, comprising a blade substrate and a nano-composite coating disposed on the surface of the blade substrate; The nanocomposite coating comprises WC, Y, Si, B, C, and O, wherein Y, Si, B, C, and O exist in the nanocomposite coating in an amorphous phase form. An sp is provided between the blade substrate and the nanocomposite coating. 2 / sp3 Hybridized carbon layers; The blade substrate is made of stainless steel.

[0007] Preferably, the blade substrate is prepared by the following method: the utility blade is ultrasonically cleaned in acetone and ethanol at a frequency of 30-40 kHz for 15-20 minutes each, then rinsed with deionized water 3-5 times, placed in tannic acid solution, and soaked in a constant temperature water bath at 23-27°C for 30-40 minutes, then rinsed with deionized water 3-5 times, and purged with nitrogen at 80°C for 10-12 minutes to obtain the blade substrate.

[0008] Preferably, the tannic acid solution is prepared by the following method: dissolving 5-8 parts by weight of tannic acid in 95-100 parts by weight of deionized water, stirring until completely dissolved, and adjusting the pH of the solution to 2.9-3.1 with 0.1M hydrochloric acid solution to obtain the tannic acid solution.

[0009] Preferably, the sp 2 / sp 3 The hybrid carbon layer was created by immersing the blade substrate in a 0.1 wt% nickel acetate-ethanol solution, performing a dip-coating once, then drying it in air at 100-105°C for 5-8 minutes, and finally placing it in a vacuum furnace, where the vacuum level was evacuated to no higher than 5.0 × 10⁻⁶. -4 Pa was heated from room temperature to 550-600℃ at a rate of 10℃ / min, held at that temperature for 55-60 minutes, and then naturally cooled to room temperature in a vacuum to obtain sp. 2 / sp 3 Hybridized carbon layer.

[0010] Preferably, the nanocomposite coating is formed by the following method: using a WC target, a blade substrate with an sp2 / sp3 hybrid carbon layer is fixed on a sample holder, placed in the HiPIMS equipment chamber, heated to 350~360℃ and held for 30~40 minutes, 35~40 sccm of Ar gas is introduced and a high negative bias of -400V is applied for cleaning for 10~12 minutes, then the Ar flow rate is maintained at 35~40 sccm, and C2H2 gas is introduced at a frequency of 1Hz pulse at 0.2 sccm. The HiPIMS power is set to 5kW, the frequency to 200Hz, the pulse width to 100μs, and a negative bias of -60V pulse with a duty cycle of 50% is applied. After deposition, the temperature is raised to 400~420℃ in a vacuum environment and held for 8~10 minutes, and then cooled with the furnace to obtain the nanocomposite coating.

[0011] Preferably, the WC target material is a WC-2at.%Y-2at.%Si-2at.%B4C composite target material.

[0012] This invention also protects a method for preparing the above-mentioned high-toughness tungsten carbide nano-coated utility knife, comprising the following steps: sequentially depositing sp... 2 / sp 3 After mixing the hybrid carbon layer and the nanocomposite coating, a surface repair treatment is performed to obtain a high-toughness tungsten carbide nanocoated utility knife.

[0013] Preferably, the surface repair treatment includes the following steps: transferring the blade substrate with the nanocomposite coating to the PECVD equipment, introducing a mixed gas of methane and hydrogen, adjusting the total working pressure to stabilize at 10~15Pa, heating the substrate to 480~500℃, turning on the 13.56MHz radio frequency power supply, setting the power to 300W, treating for 18~20 minutes, turning off the power supply and gas supply, and allowing it to cool naturally to room temperature.

[0014] Preferably, the volumetric flow rate ratio of methane to hydrogen is 4~5:1.

[0015] The present invention has the following beneficial effects: This invention utilizes blade substrate treatment and sp 2 / sp 3 A high-toughness tungsten carbide nano-coated utility knife was prepared by combining a hybrid carbon layer, a nanocomposite coating, and surface repair treatment. It possesses high hardness, high toughness, high adhesion, and low friction properties.

[0016] (1) The present invention utilizes the fact that under acidic conditions with a pH close to 3, the oxide layer on the surface of stainless steel will slightly dissolve, exposing Fe. 3+ and Cr 3+ When metal ions are present, the two adjacent hydroxyl groups on the catechol group in the tannic acid molecule will undergo coordination reactions with these metal ions to form stable five-membered or six-membered ring chelates, thereby forming a tannic acid-metal complex layer on the substrate surface. In the subsequent pyrolysis step, this complex will serve as an in-situ carbon source and structural template, ensuring that the carbon layer of the pyrolysis product can uniformly cover the substrate surface. At the same time, due to the chemical bonding at its bottom, the final carbon layer has a strong covalent bond with the substrate, thereby enhancing the adhesion of the coating.

[0017] (2) This invention introduces Ni as a catalyst, utilizing its dissolution-precipitation mechanism for carbon at high temperatures. When the temperature is raised to 550℃, carbon atoms have a high diffusion capacity on the surface of Ni particles. Ni particles can significantly reduce the activation energy of graphitization from about 500 kJ / mol to about 250 kJ / mol, thus catalyzing sp. 3 Carbon to thermodynamically more stable sp 2 Graphite phase transformation, thus forming sp 2 / sp 3 Mixed carbon layers. Among them, diamond-like carbon sp...3 Carbon provides high bonding strength and high hardness support between the coating and the substrate, while graphite-like sp 2 Carbon provides good toughness and conductivity, which is beneficial for the application of bias voltage and the uniform growth of nanocomposite coatings during the subsequent HiPIMS deposition process.

[0018] (3) Based on the Zener pinning effect and the Hall-Page effect, the carbon atoms introduced by the C2H2 pulse in this invention segregate at the grain boundaries. C2H2 is then split into C atoms in the plasma. These C atoms are enriched at the WC grain boundaries, increasing the energy barrier for grain boundary migration and effectively inhibiting the growth of WC grains, thus obtaining ultrafine WC nanocrystals and significantly improving the hardness of the coating. Y, Si, and B elements are added to the target material. These are typical amorphous forming elements. Their atomic size and chemical properties differ greatly from those of C and O. They are difficult to form an ordered lattice in the rapid condensation PVD process. During the deposition process, they form a coating around the WC grains with C and the unavoidable residual O. The surrounding amorphous phase, when the coating is subjected to stress, can absorb energy and passivate crack tips through its own slip and deformation, thereby preventing crack propagation between hard WC grains and giving the coating excellent toughness. The HiPIMS technology has extremely high pulse power density and can generate metal plasma with high ionization rate. These high-energy ions bombard the growing film. Under the bombardment of high-energy particle stream and the guidance of substrate bias, various atoms / ions are deposited, migrated and reacted on the substrate surface, and self-organize into the lowest energy nanocrystalline / amorphous composite structure according to thermodynamic and kinetic conditions. This makes the coating structure exceptionally dense and free of pores and defects, thereby improving the coating's corrosion resistance and mechanical properties.

[0019] (4) The hydrogen free radicals generated by H2 in this invention have strong chemical activity. They preferentially etch away carbon atoms with high energy, loose structure or unstable bonding at the edge of defects or the top of nodules, thereby cleaning the micro-defects protruding on the coating surface. The methyl free radicals generated by CH4 tend to be stably adsorbed and polymerized into a film in the low-energy depressions or inside the defects cleaned by hydrogen free radicals, thereby selectively filling the defects and forming a solid hydrogenated amorphous carbon film, thereby slowing down the performance degradation rate of the coating and extending the life of the coating. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cut surface of the high-toughness tungsten carbide nano-coated utility knife of the present invention.

[0021] Figure 2 This is a flowchart illustrating the preparation process of the high-toughness tungsten carbide nano-coated utility knife of the present invention. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] The stainless steel used for the blade substrate in this embodiment is 440C stainless steel.

[0024] like Figure 1 As shown, a high-toughness tungsten carbide nano-coated utility knife of the present invention includes a blade substrate and a nano-composite coating disposed on the surface of the blade substrate; The nanocomposite coating comprises WC, Y, Si, B, C, and O, wherein Y, Si, B, C, and O exist in the nanocomposite coating in an amorphous phase form. An sp is provided between the blade substrate and the nanocomposite coating. 2 / sp 3 Hybridized carbon layers; The blade substrate is made of stainless steel.

[0025] In some embodiments, the blade substrate is prepared by the following method: the utility blade is ultrasonically cleaned in acetone and ethanol at a frequency of 40 kHz for 15 minutes each, then rinsed with deionized water 3 times, placed in tannic acid solution, and soaked in a constant temperature water bath at 23~27℃ for 30 minutes, then taken out and rinsed with deionized water 3 to 5 times, and purged with nitrogen at 80℃ for 10 minutes to obtain the blade substrate.

[0026] It is understood that in the embodiments of this application, tannic acid is a natural polyphenol compound containing a large number of catechol groups in its molecular structure, which are extremely strong metal ion chelating agents. Under acidic conditions with a pH close to 3, the oxide layer on the stainless steel surface will slightly dissolve, exposing Fe. 3+ and Cr 3+ When metal ions are present, the two adjacent hydroxyl groups on the catechol group in the tannic acid molecule will undergo coordination reactions with these metal ions to form stable five-membered or six-membered ring chelates, thereby forming a tannic acid-metal complex layer on the substrate surface. In the subsequent pyrolysis step, this complex will serve as an in-situ carbon source and structural template, ensuring that the carbon layer of the pyrolysis product can uniformly cover the substrate surface. At the same time, due to the chemical bonding at its bottom, the final carbon layer has a strong covalent bond with the substrate, thereby enhancing the adhesion of the coating.

[0027] In some embodiments, the tannic acid solution is prepared by dissolving 5 parts by weight of tannic acid in 95 parts by weight of deionized water, stirring until completely dissolved, and adjusting the pH of the solution to 2.9-3.1 with 0.1M hydrochloric acid solution to obtain the tannic acid solution.

[0028] In some embodiments, the sp 2 / sp 3 The hybrid carbon layer was prepared by immersing the blade substrate in a 0.1 wt% nickel acetate-ethanol solution, performing a dip-coating once, then drying it in air at 100°C for 5 minutes, and finally placing it in a vacuum furnace, where the vacuum level was evacuated to no higher than 5.0 × 10⁻⁶. -4 Pa was heated from room temperature to 550-600℃ at a rate of 10℃ / min, held at that temperature for 60 minutes, and then naturally cooled to room temperature in a vacuum to obtain sp. 2 / sp 3 Hybridized carbon layer.

[0029] It is understood that in the embodiments of this application, Ni is introduced as a catalyst, utilizing its dissolution-precipitation mechanism for carbon at high temperatures. When the temperature is raised to 550°C, carbon atoms have a high diffusion capacity on the surface of Ni particles. Ni particles can significantly reduce the activation energy of graphitization from about 500 kJ / mol to about 250 kJ / mol, thus catalyzing sp. 3 Carbon to thermodynamically more stable sp 2 Graphite phase transformation, thus forming sp 2 / sp 3 Mixed carbon layers. Among them, diamond-like carbon sp... 3 Carbon provides high bonding strength and high hardness support to the matrix, while graphite-like sp 2 Carbon provides good toughness and conductivity, which is beneficial for the application of bias voltage and the uniform growth of nanocomposite coatings during the subsequent HiPIMS deposition process.

[0030] In some embodiments, the nanocomposite coating is formed by the following method: using a WC target, a nanocomposite coating is formed on the target. 2 / sp 3 The blade substrate with hybrid carbon layer was fixed on the sample holder, placed in the HiPIMS equipment chamber, heated to 350℃ and held for 30 minutes, and then purged with 40 sccm of Ar gas and a high negative bias of -400V for 10 minutes. After that, the Ar flow rate was maintained at 40 sccm, and 0.2 sccm of C2H2 gas was pulsed at a frequency of 1Hz. The HiPIMS power was set to 5kW, the frequency to 200Hz, the pulse width to 100μs, and a negative bias of -60V pulse with a duty cycle of 50% was applied. After deposition, the temperature was raised to 400℃ in a vacuum environment and held for 10 minutes. The material was then cooled with the furnace to obtain the nanocomposite coating.

[0031] In some embodiments, the WC target is a WC-2at.%Y-2at.%Si-2at.%B4C composite target.

[0032] Understandably, in the embodiments of this application, based on the Zener pinning effect and the Hall-Page effect, carbon atoms introduced by the C2H2 pulse segregate at the grain boundaries. C2H2 then splits into C atoms in the plasma. These C atoms accumulate at the WC grain boundaries, increasing the energy barrier for grain boundary migration and effectively suppressing WC grain growth, resulting in ultrafine WC nanocrystals and significantly improving the coating hardness. The addition of Y, Si, and B elements to the target material, typical amorphous forming elements, significantly differs from C and O in atomic size and chemical properties. They are difficult to form an ordered lattice during the rapid condensation PVD process and, during deposition, form a coating encapsulation with C and unavoidable residual O. The amorphous phase surrounding the WC grains can absorb energy and passivate crack tips through its own slip and deformation when the coating is under stress, thereby preventing crack propagation between hard WC grains and giving the coating excellent toughness. The HiPIMS technology, with its extremely high pulse power density, can generate metal plasma with high ionization rate. These high-energy ions bombard the growing film. Under the bombardment of high-energy particle streams and the guidance of substrate bias, various atoms / ions are deposited, migrated, and reacted on the substrate surface. According to thermodynamic and kinetic conditions, they self-organize to form a nanocrystalline / amorphous composite structure with the lowest energy, making the coating structure exceptionally dense and free of pores and defects, thereby improving the coating's corrosion resistance and mechanical properties.

[0033] like Figure 2 As shown, one embodiment of this application also discloses a method for preparing the above-mentioned high-toughness tungsten carbide nano-coated utility knife, including the following steps: sequentially depositing sp... 2 / sp 3 After mixing the hybrid carbon layer and the nanocomposite coating, a surface repair treatment is performed to obtain a high-toughness tungsten carbide nanocoated utility knife.

[0034] Preferably, the surface repair treatment includes the following steps: transferring the blade substrate with the nanocomposite coating to the PECVD equipment, introducing a mixed gas of methane and hydrogen, adjusting the total working pressure to stabilize at 10Pa, heating the substrate to 500°C, turning on the 13.56MHz radio frequency power supply, setting the power to 300W, processing for 20 minutes, turning off the power supply and gas supply, and allowing it to cool naturally to room temperature.

[0035] In some embodiments, the volume flow ratio of methane to hydrogen is 4:1.

[0036] It is understood that in the embodiments of this application, the hydrogen free radicals generated by H2 have strong chemical activity. They preferentially etch away carbon atoms with high energy, loose structure, or unstable bonding at defect edges or nodule tops, thereby cleaning the microscopic defects protruding on the coating surface. The methyl free radicals generated by CH4 tend to be stably adsorbed and polymerized into a film in the low-energy depressions or inside the defects cleaned by hydrogen free radicals, achieving selective filling of defects and forming a solid hydrogenated amorphous carbon film, thereby slowing down the performance degradation rate of the coating and extending the coating life.

[0037] Example 1 This embodiment yields a cutting surface of a high-toughness tungsten carbide nano-coated utility knife, comprising a blade substrate and a nano-composite coating disposed on the surface of the blade substrate; The nanocomposite coating comprises WC, Y, Si, B, C, and O, wherein Y, Si, B, C, and O exist in the nanocomposite coating in an amorphous phase form. An sp is provided between the blade substrate and the nanocomposite coating. 2 / sp 3 Hybridized carbon layers; The blade substrate is made of stainless steel.

[0038] In this embodiment, the blade substrate is prepared by the following method: the utility blade is ultrasonically cleaned in acetone and ethanol at a frequency of 40kHz for 15 minutes each, then rinsed with deionized water 3 times, placed in tannic acid solution, and soaked in a constant temperature water bath at 25°C for 30 minutes. After being taken out, it is rinsed with deionized water 3 times and purged with nitrogen at 80°C for 10 minutes to obtain the blade substrate.

[0039] In this embodiment, the tannic acid solution is prepared by the following method: 5 parts by weight of tannic acid are dissolved in 95 parts by weight of deionized water, stirred until completely dissolved, and the pH value of the solution is adjusted to 3.0 with 0.1M hydrochloric acid solution to obtain the tannic acid solution.

[0040] In this embodiment, the sp 2 / sp 3 The hybrid carbon layer was prepared by immersing the blade substrate in a 0.1 wt% nickel acetate-ethanol solution, performing a dip-coating once, drying it in air at 100°C for 5 minutes, and then placing it in a vacuum furnace, where the vacuum level was evacuated to 3.0 × 10⁻⁶. -4 Pa was heated from room temperature to 570°C at a rate of 10°C / min and held at that temperature for 60 minutes. After the holding period, it was naturally cooled to room temperature in a vacuum to obtain sp. 2 / sp 3 Hybridized carbon layer.

[0041] In this embodiment, the nanocomposite coating is formed by the following method: using a WC target, a nanocomposite coating is formed on the target. 2 / sp 3 The blade substrate with hybrid carbon layer was fixed on the sample holder, placed in the HiPIMS equipment chamber, heated to 350℃ and held for 30 minutes, and then purged with 40 sccm of Ar gas and a high negative bias of -400V for 10 minutes. After that, the Ar flow rate was maintained at 40 sccm, and 0.2 sccm of C2H2 gas was pulsed at a frequency of 1Hz. The HiPIMS power was set to 5kW, the frequency to 200Hz, the pulse width to 100μs, and a negative bias of -60V pulse with a duty cycle of 50% was applied. After deposition, the temperature was raised to 400℃ in a vacuum environment and held for 10 minutes. The material was then cooled with the furnace to obtain the nanocomposite coating.

[0042] In this embodiment, the WC target material is a WC-2at.%Y-2at.%Si-2at.%B4C composite target material.

[0043] The preparation method of the high-toughness tungsten carbide nano-coated utility knife in this embodiment includes the following steps: sequentially setting sp... 2 / sp 3 After mixing the hybrid carbon layer and the nanocomposite coating, a surface repair treatment is performed to obtain a high-toughness tungsten carbide nanocoated utility knife.

[0044] In this embodiment, the surface repair treatment includes the following steps: transferring the blade substrate with the nanocomposite coating to the PECVD equipment, introducing a mixed gas of methane and hydrogen, adjusting the total working pressure to stabilize at 10Pa, heating the substrate to 500°C, turning on the 13.56MHz radio frequency power supply, setting the power to 300W, processing for 20 minutes, turning off the power supply and gas source, and allowing it to cool naturally to room temperature.

[0045] In this embodiment, the volume flow ratio of methane to hydrogen is 4:1.

[0046] Example 2 This embodiment yields a cutting surface of a high-toughness tungsten carbide nano-coated utility knife, comprising a blade substrate and a nano-composite coating disposed on the surface of the blade substrate; The nanocomposite coating comprises WC, Y, Si, B, C, and O, wherein Y, Si, B, C, and O exist in the nanocomposite coating in an amorphous phase form. An sp is provided between the blade substrate and the nanocomposite coating. 2 / sp 3 Hybridized carbon layers; The blade substrate is made of stainless steel.

[0047] In this embodiment, the blade substrate is prepared by the following method: the utility blade is ultrasonically cleaned in acetone and ethanol at a frequency of 40kHz for 15 minutes each, then rinsed with deionized water 3 times, placed in tannic acid solution, and soaked in a constant temperature water bath at 23°C for 30 minutes. After being taken out, it is rinsed with deionized water 5 times and purged with nitrogen at 80°C for 10 minutes to obtain the blade substrate.

[0048] In this embodiment, the tannic acid solution is prepared by the following method: 5 parts by weight of tannic acid are dissolved in 95 parts by weight of deionized water, stirred until completely dissolved, and the pH value of the solution is adjusted to 2.9 with 0.1M hydrochloric acid solution to obtain the tannic acid solution.

[0049] In this embodiment, the sp 2 / sp 3 The hybrid carbon layer was prepared by immersing the blade substrate in a 0.1 wt% nickel acetate-ethanol solution, performing a dip-coating once, then drying it in air at 100°C for 5 minutes, and finally placing it in a vacuum furnace, where the vacuum level was evacuated to 5.0 × 10⁻⁶. -4 Pa was heated from room temperature to 600°C at a rate of 10°C / min, held at that temperature for 60 minutes, and then naturally cooled to room temperature in a vacuum to obtain sp. 2 / sp 3 Hybridized carbon layer.

[0050] In this embodiment, the nanocomposite coating is formed by the following method: using a WC target, a nanocomposite coating is formed on the target. 2 / sp 3 The blade substrate with hybrid carbon layer was fixed on the sample holder, placed in the HiPIMS equipment chamber, heated to 350℃ and held for 30 minutes, and then purged with 40 sccm of Ar gas and a high negative bias of -400V for 10 minutes. After that, the Ar flow rate was maintained at 40 sccm, and 0.2 sccm of C2H2 gas was pulsed at a frequency of 1Hz. The HiPIMS power was set to 5kW, the frequency to 200Hz, the pulse width to 100μs, and a negative bias of -60V pulse with a duty cycle of 50% was applied. After deposition, the temperature was raised to 400℃ in a vacuum environment and held for 10 minutes. The material was then cooled with the furnace to obtain the nanocomposite coating.

[0051] In this embodiment, the WC target material is a WC-2at.%Y-2at.%Si-2at.%B4C composite target material.

[0052] The preparation method of the high-toughness tungsten carbide nano-coated utility knife in this embodiment includes the following steps: sequentially setting sp... 2 / sp 3 After mixing the hybrid carbon layer and the nanocomposite coating, a surface repair treatment is performed to obtain a high-toughness tungsten carbide nanocoated utility knife.

[0053] In this embodiment, the surface repair treatment includes the following steps: transferring the blade substrate with the nanocomposite coating to the PECVD equipment, introducing a mixed gas of methane and hydrogen, adjusting the total working pressure to stabilize at 10Pa, heating the substrate to 500°C, turning on the 13.56MHz radio frequency power supply, setting the power to 300W, processing for 20 minutes, turning off the power supply and gas source, and allowing it to cool naturally to room temperature.

[0054] In this embodiment, the volume flow ratio of methane to hydrogen is 4:1.

[0055] Example 3 This embodiment yields a cutting surface of a high-toughness tungsten carbide nano-coated utility knife, comprising a blade substrate and a nano-composite coating disposed on the surface of the blade substrate; The nanocomposite coating comprises WC, Y, Si, B, C, and O, wherein Y, Si, B, C, and O exist in the nanocomposite coating in an amorphous phase form. An sp is provided between the blade substrate and the nanocomposite coating. 2 / sp 3 Hybridized carbon layers; The blade substrate is made of stainless steel.

[0056] In this embodiment, the blade substrate is prepared by the following method: the utility blade is ultrasonically cleaned in acetone and ethanol at a frequency of 40kHz for 15 minutes each, then rinsed with deionized water 3 times, placed in tannic acid solution, and soaked in a constant temperature water bath at 27°C for 30 minutes. After being taken out, it is rinsed with deionized water 4 times and purged with nitrogen at 80°C for 10 minutes to obtain the blade substrate.

[0057] In this embodiment, the tannic acid solution is prepared by the following method: 5 parts by weight of tannic acid are dissolved in 95 parts by weight of deionized water, stirred until completely dissolved, and the pH value of the solution is adjusted to 3.1 with 0.1M hydrochloric acid solution to obtain the tannic acid solution.

[0058] In this embodiment, the sp 2 / sp 3 The hybrid carbon layer was prepared by immersing the blade substrate in a 0.1 wt% nickel acetate-ethanol solution, performing a dip-coating once, drying it in air at 100°C for 5 minutes, and then placing it in a vacuum furnace, where the vacuum level was evacuated to 4.0 × 10⁻⁶. -4 Pa was heated from room temperature to 550°C at a rate of 10°C / min and held at that temperature for 60 minutes. After the holding period, it was naturally cooled to room temperature in a vacuum to obtain sp. 2 / sp 3 Hybridized carbon layer.

[0059] In this embodiment, the nanocomposite coating is formed by the following method: using a WC target, a nanocomposite coating is formed on the target. 2 / sp 3 The blade substrate with hybrid carbon layer was fixed on the sample holder, placed in the HiPIMS equipment chamber, heated to 350℃ and held for 30 minutes, and then purged with 40 sccm of Ar gas and a high negative bias of -400V for 10 minutes. After that, the Ar flow rate was maintained at 40 sccm, and 0.2 sccm of C2H2 gas was pulsed at a frequency of 1Hz. The HiPIMS power was set to 5kW, the frequency to 200Hz, the pulse width to 100μs, and a negative bias of -60V pulse with a duty cycle of 50% was applied. After deposition, the temperature was raised to 400℃ in a vacuum environment and held for 10 minutes. The material was then cooled with the furnace to obtain the nanocomposite coating.

[0060] In this embodiment, the WC target material is a WC-2at.%Y-2at.%Si-2at.%B4C composite target material.

[0061] The preparation method of the high-toughness tungsten carbide nano-coated utility knife in this embodiment includes the following steps: sequentially setting sp... 2 / sp 3 After mixing the hybrid carbon layer and the nanocomposite coating, a surface repair treatment is performed to obtain a high-toughness tungsten carbide nanocoated utility knife.

[0062] In this embodiment, the surface repair treatment includes the following steps: transferring the blade substrate with the nanocomposite coating to the PECVD equipment, introducing a mixed gas of methane and hydrogen, adjusting the total working pressure to stabilize at 10Pa, heating the substrate to 500°C, turning on the 13.56MHz radio frequency power supply, setting the power to 300W, processing for 20 minutes, turning off the power supply and gas source, and allowing it to cool naturally to room temperature.

[0063] In this embodiment, the volume flow ratio of methane to hydrogen is 4:1.

[0064] Comparative Example 1 In this embodiment, sp is not set. 2 / sp 3 The mixed hybrid carbon layer is the same as in Example 1.

[0065] Comparative Example 2 In this embodiment, no nanocomposite coating is provided; otherwise, it is the same as in Embodiment 1.

[0066] Comparative Example 3 In this embodiment, no surface repair treatment is performed; otherwise, it is the same as in Embodiment 1.

[0067] Comparative Example 4 In this embodiment, a regular stainless steel utility knife blade is used instead of the blade base, and the rest is the same as in Embodiment 1.

[0068] The high-toughness tungsten carbide nano-coated utility knives prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance testing. The test results are shown in Table 1 below: Table 1

[0069] As can be seen from Table 1, the microhardness of Examples 1-3 is all above 28.8 GPa. Comparative Example 2, however, only contains sp... 2 / sp 3 The hardness of the hybrid carbon layer without the WC hard layer was corrected to 18.5 GPa, which was much lower than that of the example, but significantly higher than that of the ordinary stainless steel substrate by about 7 GPa. In contrast, the coating growth quality and density of Comparative Example 4 decreased due to the use of an ordinary substrate that was not treated with tannic acid, and its hardness was significantly lower than that of Example 1.

[0070] As can be seen from Table 1, the bonding strength of Examples 1-3 all exceeded 56 N, while the bonding strength of Comparative Example 1 was only 21.5 N, and the bonding strength of Comparative Example 4 was as low as 15.8 N, indicating that sp 2 / sp 3 The hybrid carbon layer effectively alleviates the thermal and modulus mismatch between the substrate and the hard coating, thereby improving the bonding strength.

[0071] As can be seen from Table 1, Examples 1-3 exhibited excellent friction coefficients and wear rates. In particular, compared with Comparative Example 3, this indicates that the PECVD process not only filled microscopic defects but, more importantly, formed a layer rich in sp on the outermost surface of the coating. 2 The graphite-like carbon lubricating film formed by the bonding acts as a solid lubricant during friction, thus significantly reducing coating friction and wear. Comparative Examples 1, 2, and 4 exhibited extremely high wear rates, primarily due to poor adhesion leading to coating peeling or insufficient hardness.

[0072] As can be seen from Table 1, the cutting length of Examples 1-3 can reach up to 920 meters. The lifespan of Comparative Example 3 is only about half that of Example 3, mainly due to the high friction causing the blade to become dull quickly. The lifespans of Comparative Examples 1 and 4 are only 110 meters and 70 meters respectively, due to early coating peeling and blade chipping. Comparative Example 2 has the shortest lifespan, only 45 meters, because its hardness is insufficient to resist the wear of the hard fibers in the corrugated cardboard.

[0073] In summary, this invention improves upon blade substrate treatment and sp... 2 / sp 3A high-toughness tungsten carbide nano-coated utility knife was prepared by combining a hybrid carbon layer, a nanocomposite coating, and surface repair treatment. It possesses high hardness, high toughness, high adhesion, and low friction properties.

[0074] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A high-toughness tungsten carbide nano-coated utility knife, characterized in that, The cutting blade base body and the nanocomposite coating arranged on the surface of the cutting blade base body; The nanocomposite coating comprises WC, Y, Si, B, C and O, and the Y, Si, B, C and O exist in the nanocomposite coating in an amorphous phase. sp 2 sp 3 mixed hybrid carbon layer.

2. The high-toughness tungsten carbide nanocoated utility knife of claim 1, wherein, The cutting blade base body is made of stainless steel.

3. The high-toughness tungsten carbide nanocoated utility knife of claim 1, wherein, The cutting blade base body is prepared by the following method: sequentially ultrasonic cleaning a stationery knife blade in acetone and ethanol at a frequency of 30-40 kHz for 15-20 minutes, then rinsing with deionized water for 3-5 times, placing in a tannic acid solution, standing and soaking in a constant-temperature water bath at 23-27 DEG C for 30-40 minutes, taking out and rinsing with deionized water for 3-5 times, and blowing with nitrogen at 80 DEG C for 10-12 minutes to obtain the cutting blade base body.

4. The high-toughness tungsten carbide nanocoated utility knife of claim 3, wherein, The tannic acid solution is prepared by the following method: dissolving 5-8 parts of tannic acid in 95-100 parts of deionized water by weight, stirring until completely dissolved, and adjusting the pH value of the solution to 2.9-3.1 with a 0.1M hydrochloric acid solution to obtain the tannic acid solution.

5. The high-toughness tungsten carbide nanocoated utility knife of claim 1, wherein, The sp 2 / sp 3 The mixed hybrid carbon layer is set by immersing the blade base into a 0.1wt% nickel acetate ethanol solution, once by pulling and dip-coating, and then drying in air at 100-105℃ for 5-8 minutes, placing in a vacuum furnace, and drawing the vacuum in the furnace to not higher than 5.0×10 -4 Pa, increasing from room temperature to 550-600℃ at a rate of 10℃ / min, holding for 55-60 minutes, and after the holding ends, naturally cooling to room temperature in vacuum, to obtain sp 2 / sp 3 The mixed hybrid carbon layer.

6. The high-toughness tungsten carbide nanocoated utility knife of claim 1, wherein, The nanocomposite coating is set by using a WC target, setting a sp 2 / sp 3 The blade substrate of the mixed hybrid carbon layer is fixed on a sample holder, placed in the chamber of the HiPIMS device, heated to 350-360 DEG C and kept for 30-40 minutes, 35-40 sccm Ar gas is introduced to apply-400V high negative bias for 10-12 minutes, then the Ar flow is maintained at 35-40 sccm, C2H2 gas is pulsed at a frequency of 1 Hz and a flow rate of 0.2 sccm, the HiPIMS power is set to 5kW, the frequency is 200Hz, the pulse width is 100us, the pulse negative bias is-60V with a duty cycle of 50%, after deposition, the temperature is raised to 400-420 DEG C in a vacuum environment for 8-10 minutes, and then the furnace is cooled to obtain a nanocomposite coating.

7. The high-toughness tungsten carbide nanocoated utility knife of claim 6, wherein, The WC target material is a WC-2at.%Y-2at.%Si-2at.%B4C composite target material.

8. A method of making a high toughness tungsten carbide nanocoated utility knife according to any one of claims 1 to 7, wherein, The method comprises the following steps: sp 2 sp 3 After mixing the hybrid carbon layer and the nanocomposite coating, surface repair treatment is performed to obtain a high-toughness tungsten carbide nanocoating art knife.

9. The production method according to claim 8, characterized by, The surface repair treatment comprises the following steps: transferring the cutting blade base body provided with the nanocomposite coating into a PECVD device, introducing a mixed gas of methane and hydrogen, adjusting the total working pressure to be stable at 10-15 Pa, heating the base body to 480-500 DEG C, turning on a 13.56 MHz radio frequency power source with a power setting of 300 W, and treating for 18-20 minutes, then turning off the power source and the gas source, and naturally cooling to room temperature.

10. The method of claim 9, wherein, The volume flow ratio of the methane and hydrogen is 4-5:1.

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