Amorphous boron nitride wear-resistant corrosion-resistant heat-insulating film for marine equipment window glass and preparation method thereof

Abstract

This invention discloses an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating thin film for marine equipment viewing windows and its preparation method, belonging to the technical field of functional protective thin film materials. It aims to solve the problems of insufficient wear resistance, susceptibility to corrosion, and difficulty in simultaneously achieving heat insulation and transparency in glass substrate components in marine environments. This invention uses glass as a substrate and employs magnetron sputtering to deposit an amorphous boron nitride thin film. By precisely controlling key process parameters such as argon flow rate (15-20 sccm), nitrogen partial pressure (0.1-0.5 Pa), radio frequency power (150-200 W), and substrate bias (30-50 V), a pure amorphous boron nitride thin film with a thickness of 180-200 nm is prepared. The thin film prepared by this invention possesses excellent wear resistance, corrosion resistance, heat insulation performance, and high transparency, achieving a multi-functional synergistic effect. It is adaptable to harsh marine environments such as high salt spray, high humidity, and large temperature differences, and is suitable for the protection of transparent components such as marine observation windows, navigation equipment lenses, and instrument panel transparent covers, significantly extending the service life of marine equipment viewing windows.

Description

Technical Field

[0001] This invention relates to the field of functional protective film materials technology, specifically to an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows and its preparation method. Background Technology

[0002] Marine equipment viewing windows are key transparent components of ships, submarines, and marine observation platforms. They are widely used in observation windows, navigation equipment lenses, and instrument panel covers, performing crucial functions such as observation, detection, and optical imaging. Their service environment is characterized by typical marine climate features: high salt spray, high humidity, and strong corrosion. They also face the combined effects of wave impact, wind and sand abrasion, and drastic temperature changes. Corrosion and abrasion not only reduce the glass's light transmittance, affecting observation accuracy, but also cause surface fogging due to a lack of effective thermal insulation, limiting the equipment's all-weather operational capabilities. Therefore, there is an urgent need to develop a multifunctional protective film that combines wear resistance, corrosion resistance, thermal insulation, and high transparency to meet the stringent requirements of marine equipment viewing windows.

[0003] Currently, the protective methods for marine equipment windows are mainly divided into two categories: organic coatings and traditional inorganic coatings. Organic coatings, such as fluoropolymers, while possessing a certain degree of transparency and hydrophobicity, have poor weather resistance and are prone to aging, yellowing, and even peeling in marine environments with high salt spray and strong ultraviolet radiation, making them unsuitable for long-term service. Traditional inorganic coatings, such as hard films like silicon dioxide (SiO2) and titanium dioxide (TiO2), can improve the surface hardness and wear resistance of glass, but single-component films cannot simultaneously achieve the thermal insulation function with low infrared emissivity, and some oxide films suffer from insufficient chemical stability in marine environments.

[0004] Boron nitride thin films have become a research hotspot in transparent protective materials in recent years due to their excellent chemical stability, good mechanical properties, and wide transmittance band. Based on their crystal structure, boron nitride thin films can be divided into cubic boron nitride and hexagonal boron nitride. Cubic boron nitride possesses extremely high hardness, but its preparation process typically requires high temperatures (>400℃) and high bias voltages. Furthermore, the high internal stress of the film makes it prone to thermal expansion mismatch with the glass substrate, leading to delamination and making direct application on glass substrates difficult. For example, patent CN102560357B discloses a method for preparing cubic boron nitride optical thin films, using radio frequency magnetron sputtering to deposit cubic boron nitride films on single-crystal silicon substrates. Silicon is added to the target material to control stress. However, the preparation process requires high temperatures of 430-470℃ and high bias voltages of 500-600V, as well as high-temperature annealing treatment at 800-900℃. These process conditions are unsuitable for glass substrates, and the prepared cubic boron nitride films primarily pursue high hardness without addressing thermal insulation functions.

[0005] On the other hand, amorphous boron nitride thin films exhibit potential advantages in the field of transparent protection due to their uniform structure, absence of grain boundaries, and strong chemical inertness. However, existing fabrication processes for amorphous boron nitride thin films mostly focus on achieving single functions, such as hydrophobicity or optical transmittance, failing to fully leverage their multifunctional synergistic potential. For example, patent CN200510114853.9 discloses a method for preparing transparent hydrophobic boron nitride thin films, employing vapor deposition combined with subsequent plasma etching to form microscopic protrusion structures on the film surface to achieve hydrophobic properties. However, this technical solution does not address the optimization of the film's wear resistance, corrosion resistance, and thermal insulation performance, and the etching process increases the complexity of the process, making it difficult to meet the comprehensive performance requirements of protective films in marine environments.

[0006] In summary, current technologies lack a boron nitride thin film that can be directly fabricated on a glass substrate and possesses wear resistance, corrosion resistance, heat insulation, and high transparency. In particular, there is a lack of a multifunctional integrated protection solution specifically designed for the viewing windows of marine equipment. Therefore, developing an amorphous boron nitride thin film adapted to the harsh marine environment and capable of multifunctional synergy, along with its fabrication method, has significant practical implications and application value. Summary of the Invention

[0007] The purpose of this invention is to provide an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows and its preparation method. This invention addresses the problems of insufficient wear resistance, easy corrosion, and difficulty in balancing heat insulation and transparency in glass substrate components in marine environments. It also overcomes the shortcomings of existing amorphous boron nitride films with limited functionality, achieving a synergistic effect of wear resistance, corrosion resistance, heat insulation, and high transparency, thus meeting the usage requirements of marine equipment viewing windows in harsh marine environments.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows includes the following steps: (1) Substrate pretreatment: Glass was selected as the substrate and was ultrasonically cleaned and dried in sequence with acetone, anhydrous ethanol and deionized water to obtain a clean glass substrate; (2) Target installation: A high-purity hexagonal boron nitride target is installed on the radio frequency power supply, with argon as the working gas and nitrogen as the supplementary nitrogen source to construct an amorphous boron nitride deposition system. (3) Vacuuming: Place the clean glass substrate obtained in step (1) into the reaction chamber of the magnetron sputtering instrument and perform vacuuming on the chamber; (4) Substrate cleaning: Inert gas is introduced into the chamber, substrate heating and substrate bias are turned on, and the glass substrate is cleaned by back sputtering. (5) Target pre-sputtering: Turn off the substrate bias, adjust the inert gas flow rate and chamber pressure, turn on the RF power supply to pre-sputter the hexagonal boron nitride target, and turn off the target baffle to avoid impurity deposition. (6) Thin film deposition: Adjust the mixing ratio of argon and nitrogen, the chamber pressure, turn on the RF power supply and substrate bias, set the substrate rotation speed, and deposit an amorphous boron nitride thin film on the surface of the glass substrate to obtain an amorphous boron nitride multifunctional transparent protective film.

[0009] As a preferred embodiment of the present invention, the glass substrate in step (1) is a transparent tempered glass for marine equipment, which is 20 mm long, 20 mm wide and 5 mm thick; the specific operation of the solvent ultrasonic cleaning is: the glass substrate is placed in acetone for 15 min, in anhydrous ethanol for 15 min and in deionized water for 15 min in sequence; the drying method is to dry in a vacuum drying oven at 80 ℃ for 30 min.

[0010] As a preferred embodiment of the present invention, the high-purity hexagonal boron nitride target in step (2) has a purity of ≥99.99%, a diameter of 50 mm, and a thickness of 4 mm.

[0011] As a preferred embodiment of the present invention, the vacuuming process in step (3) is as follows: first, a mechanical pump is used to evacuate to a vacuum level < 9 Pa, and then a molecular pump is switched to continue evacuating to a vacuum level < 1 × 10 Pa. -3 Pa; and during the vacuuming process, the temperature of the magnetron sputtering reaction chamber is kept at room temperature.

[0012] As a preferred embodiment of the present invention, the inert gas in step (4) is argon, with a flow rate of 50-100 sccm and a chamber pressure controlled at 5-10 Pa; the substrate heating temperature is 80 ℃, the substrate bias voltage is 300-500 V, and the back sputtering time is 15 min.

[0013] As a preferred embodiment of the present invention, the inert gas in step (5) is argon, the flow rate is adjusted to 20-30 sccm, and the chamber pressure is controlled to 2-3 Pa; the power of the radio frequency power supply for pre-sputtering is 80-120W, and the pre-sputtering time is 15min.

[0014] As a preferred embodiment of the present invention, the inert gas in step (6) is argon, with a flow rate of 15-20 sccm and a nitrogen partial pressure of 0.1-0.5 Pa; the RF power supply has a power of 150-200 W, a substrate bias voltage of 30-50 V, a substrate rotation speed of 5 rpm, and a deposition time of 2 hours; the thickness of the amorphous boron nitride film is 180-200 nm.

[0015] The present invention further provides an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows prepared by the above-mentioned method.

[0016] The present invention also provides an application of the above-mentioned amorphous boron nitride thin film in the field of marine equipment, including depositing the thin film on the surface of the viewing window glass of marine equipment for protection of marine observation windows, light-transmitting lenses of navigation equipment, or transparent covers of instrument panels.

[0017] Compared with the prior art, the present invention has the following beneficial effects: First, excellent adhesion and structural stability. This invention effectively removes organic contaminants and the native oxide layer from the glass substrate surface through multiple cleaning processes, including substrate pretreatment and reverse sputtering cleaning, significantly improving the adhesion strength between the amorphous boron nitride film and the glass substrate. Simultaneously, by precisely controlling the deposition parameters, the prepared film has an amorphous structure, free of grain boundaries and crystalline phase precipitation, structurally eliminating grain boundary corrosion channels and preventing film detachment under thermal cycling or wave impact, providing a structural foundation for the long-term service of the film in marine environments.

[0018] Secondly, the invention achieves a synergistic unity of wear resistance, corrosion resistance, heat insulation, and high transparency. The amorphous boron nitride thin film prepared by this invention realizes a synergistic effect of multiple functions, solving the problems of poor weather resistance of traditional organic coatings and limited functionality of inorganic coatings. In terms of wear resistance, the film's coefficient of friction is stable at 0.22~0.26, which is about 65%~68% lower than that of blank glass, and the wear rate is as low as 0.25×10⁻⁶. -7 ~0.31×10 -7 mm 3 ·N -1 ·m -1 Compared to blank glass, the corrosion rate is reduced by approximately 95% to 96%; in terms of corrosion resistance, the film's self-corrosion potential shifts positively to -0.27 to -0.32 V, and the self-corrosion current density is as low as 4.95 × 10⁻⁶ V. -8 ~7.05×10 -8 A·cm -2 Compared to blank glass, the infrared emissivity is reduced by two orders of magnitude; in terms of thermal insulation performance, the infrared emissivity of the film is 0.36~0.39, which is about 60% lower than that of blank glass, and the normal thermal conductivity is 0.31~0.39 W / (m·K), which can significantly reduce the infrared radiation heat transfer of the window glass; in terms of optical performance, the average visible light transmittance of the film is ≥86.5%, and the transmittance decrease is less than 5%, which fully meets the optical use standards for windows.

[0019] Third, the process parameters are precise and controllable, adapting to the harsh marine environment. This invention employs magnetron sputtering technology, achieving controllable preparation of amorphous boron nitride thin films by precisely controlling key parameters such as argon flow rate, nitrogen partial pressure, radio frequency power, and substrate bias. The preparation process is stable and controllable, resulting in thin films with excellent performance and good uniformity. The prepared films are suitable for harsh marine environments such as high salt spray, high humidity, large temperature differences, and wave impact. They are applicable to the protection of transparent components such as marine observation windows, instrument panel transparent covers, and navigation equipment lenses, significantly extending the service life of marine equipment viewing windows and reducing equipment maintenance costs.

[0020] Fourth, it avoids high-temperature processes and is suitable for glass substrates. The entire preparation process of this invention is carried out under low-temperature (≤80℃) conditions, avoiding problems such as glass substrate deformation and internal stress cracking caused by high-temperature treatment. At the same time, it eliminates the need for subsequent high-temperature annealing, simplifying the process flow, reducing energy consumption and production costs, and making it more suitable for large-scale industrial production of glass substrates. Attached Figure Description

[0021] Figure 1 This is a cross-sectional scanning electron microscope (SEM) image of the amorphous boron nitride thin film prepared in Example 1 of the present invention, used to characterize the thickness of the film and its bonding state with the glass substrate.

[0022] Figure 2 This is a high-resolution transmission electron microscope (HRTEM) image of the amorphous boron nitride thin film prepared in Example 1 of the present invention, used to characterize the microscopic atomic arrangement structure of the thin film.

[0023] Figure 3 This is a selected area electron diffraction (SAED) pattern of the amorphous boron nitride thin film prepared in Example 1 of the present invention, used to determine the amorphous structural characteristics of the thin film.

[0024] Figure 4 This is an atomic force microscope (AFM) image of the amorphous boron nitride thin film prepared in Example 1 of the present invention, used to test the surface roughness parameters of the thin film.

[0025] Figure 5 The X-ray photoelectron spectroscopy (XPS) fine spectra of B1s and N1s of the amorphous boron nitride thin film prepared in Example 1 of this invention are used to analyze the elemental composition and chemical bond type of the thin film.

[0026] Figure 6 This is a friction curve of the amorphous boron nitride thin film prepared in Example 1 of the present invention, used to test the stability of the friction coefficient of the film in a simulated marine environment.

[0027] Figure 7 This is a bar chart showing the wear rate of the amorphous boron nitride thin film obtained in Example 1 of the present invention after friction, used to compare the difference in wear resistance between coated glass and blank glass.

[0028] Figure 8 This is a bar chart showing the electrochemical corrosion performance of the amorphous boron nitride thin film prepared in Example 1 of the present invention, used to characterize the self-corrosion potential and self-corrosion current density of the film.

[0029] Figure 9 This is a transmittance curve of the amorphous boron nitride thin film prepared in Example 1 of the present invention in the visible light wavelength range, used to test the visible light transmittance index of the thin film.

[0030] Figure 10 The emissivity diagrams of the amorphous boron nitride thin film prepared in Example 1 of the present invention at different temperatures and surface states are used to characterize the thermal insulation performance of the thin film.

[0031] Figure 11 The graph shows the thermal conductivity of the amorphous boron nitride thin film prepared in Example 1 of this invention at different temperatures and surface conditions, which is used to test the thermal conductivity of the thin film. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are merely preferred embodiments of the present invention, and not all embodiments. This embodiment elaborates on the preparation process, process parameter control, and performance verification method of amorphous boron nitride wear-resistant and corrosion-resistant heat-insulating film for marine equipment viewing windows, aiming to fully illustrate the technical concept and feasibility of the present invention. Based on the embodiments of the present invention, all other equivalent or similar implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1 A method for preparing an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows, the method comprising: (1) Substrate pretreatment Transparent tempered glass for marine equipment was selected as the substrate, with dimensions of 20 mm in length, 20 mm in width, and 5 mm in thickness. The glass substrate was sequentially immersed in acetone, anhydrous ethanol, and deionized water, and ultrasonically cleaned for 15 min in each solution to remove surface organic contaminants and oxidized impurities. The cleaned glass substrate was then dried in an 80 ℃ vacuum drying oven for 30 min to obtain a clean glass substrate.

[0034] (2) Target installation A high-purity hexagonal boron nitride target with a purity ≥99.99%, a diameter of 50 mm, and a thickness of 4 mm was mounted on the RF power supply of a magnetron sputtering instrument. An amorphous boron nitride thin film deposition system was constructed using argon as the working gas and nitrogen as a supplementary nitrogen source.

[0035] (3) Vacuuming Place the clean glass substrate into the reaction chamber of the magnetron sputtering instrument. First, use a mechanical pump to evacuate to a vacuum level of <9 Pa, then switch to a molecular pump to continue evacuating to a vacuum level of <1×10-3 Pa, maintaining a vacuum environment in the chamber.

[0036] (4) Substrate cleaning Argon gas was introduced into the chamber at a flow rate of 70 sccm to maintain a chamber pressure of 7.4 Pa. The substrate heating function was activated, and the temperature was set to 80 ℃. At the same time, the substrate bias voltage was activated and set to 400 V. Backsputter cleaning was performed for 15 min to remove residual organic contaminants and oxide layers on the glass substrate surface and improve the adhesion between the thin film and the substrate.

[0037] (5) Target cleaning Turn off the substrate bias, adjust the argon flow rate to 25 sccm, and control the chamber pressure to 2.5 Pa. Turn on the RF power supply, set the power to 100 W, and perform a 15-minute pre-sputtering process on the hexagonal boron nitride target, closing the baffle during the process to prevent impurities on the target surface from depositing onto the substrate.

[0038] (6) Thin film preparation Adjust the argon flow rate to 18 sccm, introduce nitrogen gas and control the nitrogen partial pressure to 0.3 Pa to maintain a stable total pressure in the chamber. Turn on the RF power supply and set the power to 180 W. Simultaneously, turn on the substrate bias and set the bias voltage to 40 V. Adjust the substrate rotation speed to 5 rpm and deposit for 2 hours. Figure 1 As shown, the cross-sectional SEM image of the amorphous boron nitride thin film prepared in Example 1 of the present invention shows that an amorphous boron nitride thin film with a thickness of 190 nm was deposited on the surface of a glass substrate.

[0039] The thin film prepared in this embodiment was characterized structurally and tested for performance. The results are as follows: Structural characterization: The HRTEM morphology of the coated glass sample is as follows: Figure 2 As shown, the thin film lacks long-range ordered lattice fringes, exhibiting only locally short-range ordered atomic clusters. It lacks both the layered lattice fringes characteristic of hexagonal boron nitride and the face-centered cubic lattice fringes of cubic boron nitride. For example... Figure 3 As shown, the SAED pattern in this region exhibits broadened, diffuse halos, with no sharp diffraction rings or spots. This proves that the film is a pure amorphous boron nitride structure, without any crystalline boron nitride phase precipitation.

[0040] The boron nitride thin film prepared by this invention has a pure amorphous structure with no grain boundaries and no crystalline phase precipitation, thus eliminating grain boundary corrosion channels from a structural perspective and providing a structural basis for the film's excellent resistance to seawater and salt spray corrosion.

[0041] The roughness of the coated glass was measured using atomic force microscopy (AFM), and the AFM image is shown below. Figure 4 As shown.

[0042] After calculation, the coated glass has the following properties: R a =0.767 nm, R q =1.02 nm; After coating, the surface roughness is in a nanoscale smooth state, which not only ensures high optical transmittance of the window, but also increases the film layer bearing area, improves wear resistance and friction reduction performance, and does not affect optical imaging and observation.

[0043] X-ray photoelectron spectroscopy was used to test the bulk composition of the thin film, and the fine spectra of B 1s and N 1s are as follows: Figure 5 As shown.

[0044] The bulk phase of the thin film has a B / N atomic ratio of 1:0.95, which is close to a stoichiometric ratio of 1:1; the percentage of oxygen impurities is 1.59 at%, and there are no obvious oxide phases such as B2O3; the binding energy peak position matches the characteristic peak of amorphous boron nitride.

[0045] The film has a pure composition, a moderate stoichiometry, and a low oxygen impurity content, which avoids the looseness, decreased hardness, and reduced corrosion resistance caused by oxide phases, thus ensuring the stability of the film's mechanical and environmental resistance properties.

[0046] Performance testing: Tests were conducted on the coated glass to assess its wear resistance, corrosion resistance, optical transmission, and thermal insulation properties, thereby verifying the actual application effects of the thin film.

[0047] A reciprocating friction and wear testing machine was used; the grinding pair consisted of Si3N4 balls with a diameter of Φ6 mm; the load was set to 5 N, the reciprocating frequency to 1 Hz, the reciprocating stroke to 5 mm, and the friction duration to 3000 s; the test environment was ambient temperature and atmospheric temperature with a relative humidity of 85±5%; and 3.5 wt% NaCl solution was added to simulate a marine environment; the test parameters were the coefficient of friction and the wear rate.

[0048] The amorphous boron nitride thin film of this invention has the characteristics of low coefficient of friction, high wear resistance, and low wear rate, such as... Figure 6 As shown, the coefficient of friction of coated glass remains stable at around 0.24, which is about 68% lower than that of blank glass; Figure 7 As shown, the wear rate of the coated glass is 0.278 × 10⁻⁶. -7 mm 3 ·N -1 ·m -1 Compared to blank glass, it reduces wear by about 96%. Under conditions of ocean wind and sand erosion, daily wiping, and contact with foreign objects, it can significantly reduce glass surface wear and maintain the optical integrity and service life of the window.

[0049] The electrochemical corrosion performance of coated glass was determined using an electrochemical workstation. The electrolyte was a 3.5 wt% NaCl solution; the test system was a three-electrode system, with the sample as the working electrode, a saturated calomel electrode as the reference electrode, and a Pt sheet as the counter electrode; the test method was potentiodynamic polarization curve analysis, with a scan rate of 1 mV / s; the test parameters were self-corrosion potential and corrosion current density. The test results are shown below. Figure 8 As shown.

[0050] The self-corrosion potential of the coated sample was -0.3 V, which is significantly more positive than that of the glass sample, and the self-corrosion current density was 6.56 × 10⁻⁶. -8 A·cm -2 Compared to the glass sample, the corrosion resistance was reduced by two orders of magnitude, indicating that the amorphous boron nitride film significantly improves the thermodynamic stability and kinetic resistance of the glass surface. It also exhibits excellent resistance to pitting and electrochemical corrosion under long-term immersion in seawater, meeting the requirements for use of windows in underwater / high salt spray areas for marine equipment.

[0051] A UV-Vis-NIR spectrophotometer was used; the test wavelength was the visible light band 380~780 nm; the test index was the average visible light transmittance T. avg Test results are as follows Figure 9 As shown, the sample is double-sided polished tempered glass with a single-sided coating.

[0052] Blank glass: Average visible light transmittance T avg =91.2%; Coated glass: Average visible light transmittance T avg =87.2%; Amorphous boron nitride film is a transparent inorganic film that achieves wear resistance, corrosion resistance, and heat insulation while maintaining high visible light transmittance with a transmittance decrease of less than 5%. This does not affect the observation, detection, and optical imaging functions of marine equipment windows and meets the optical usage standards for windows.

[0053] An infrared emissivity meter was used; the test band was the 8~14 μm atmospheric window infrared band; samples at different temperatures and surface conditions were tested, and the test index was the normal total emissivity ε. The test results are as follows: Figure 10 As shown.

[0054] Blank glass: infrared emissivity ε=0.92~0.96; Coated glass: infrared emissivity ε=0.36~0.39; The amorphous boron nitride thin film of this invention has a low infrared emissivity, which is 60% lower than that of blank glass. This can significantly reduce infrared radiation heat transfer of the window glass in the marine environment, reduce heat transfer between the inside and outside of the cabin, achieve passive thermal insulation effect, and reduce the energy consumption of temperature control in marine equipment.

[0055] A laser flash thermal conductivity meter was used to test samples at different temperatures and surface conditions. The test parameter was the thermal conductivity of the thin film. The test results are as follows: Figure 11 As shown.

[0056] Thermal conductivity of blank glass: λ = 1.05~1.18 W / (m·K); Thermal conductivity of coated glass: λ = 0.31~0.39 W / (m·K); The film is amorphous and has strong phonon scattering. Combined with low emissivity radiative heat insulation, it forms a dual heat preservation mechanism of solid-phase heat transfer suppression and radiative heat insulation. Without increasing the glass thickness or sacrificing light transmittance, it significantly improves the overall heat preservation and insulation capabilities of the marine window, making it suitable for cold ocean environments with large diurnal temperature variations.

[0057] Example 2 The effects of low argon flow rate and low nitrogen partial pressure on the structure and properties of amorphous boron nitride thin films were investigated. All other steps were identical to those in Example 1, with the specific differences as follows: In step (4), the argon gas flow rate is 50 sccm, the chamber pressure is maintained at 5 Pa, and the base bias is set to 300 V; In step (5), the argon flow rate is adjusted to 20 sccm, the chamber pressure is controlled to 2 Pa, and the radio frequency power is 80W; In step (6), the argon flow rate was adjusted to 15 sccm, the nitrogen partial pressure was 0.1 Pa, the radio frequency power was 150 W, and the substrate bias was 30 V to obtain an amorphous boron nitride thin film with a thickness of 180 nm. The results were obtained after performing the same test as in Example 1: Friction performance: The coefficient of friction is stable at 0.26, and the wear rate is 0.31×10⁻⁶. -7 mm 3 ·N -1 ·m -1 Compared to blank glass, the reductions were 65% and 95% respectively; Corrosion resistance: Self-corrosion potential is -0.32 V, self-corrosion current density is 7.05 × 10⁻⁶ V. -8 A·cm -2 It has excellent resistance to pitting corrosion; Light transmittance: The average visible light transmittance is 88.5%, which is 2.7% lower than that of blank glass, meeting the optical requirements of the window. Thermal insulation performance: The infrared emissivity in the 8~14 μm band is 0.39, and the normal thermal conductivity is 0.35 W / (m·K), which provides good thermal insulation effect.

[0058] Example 3 The effects of high argon flow rate and high nitrogen partial pressure on the compactness and functional properties of amorphous boron nitride thin films were investigated. All other steps were identical to those in Example 1, with the specific differences as follows: In step (4), the argon gas flow rate is 100 sccm, the chamber pressure is maintained at 10 Pa, and the base bias voltage is set to 500V; In step (5), the argon flow rate is adjusted to 30 sccm, the chamber pressure is controlled to 3 Pa, and the radio frequency power is 120W; In step (6), the argon flow rate was adjusted to 20 sccm, the nitrogen partial pressure was 0.5 Pa, the radio frequency power was 200 W, and the substrate bias was 50 V to obtain an amorphous boron nitride thin film with a thickness of 200 nm. The results were obtained after performing the same test as in Example 1: Wear resistance: The coefficient of friction remains stable at 0.22, and the wear rate is as low as 0.25×10⁻⁶. -7 mm 3 ·N -1 ·m -1 Its wear resistance is superior to that of Example 1; Corrosion resistance: Self-corrosion potential is -0.27 V, and self-corrosion current density is 4.95 × 10⁻⁶. -8 A·cm -2 No obvious corrosion spots were observed after electrochemical corrosion. Light transmittance: The average transmittance of visible light is 86.5%, which is 4.7% lower than that of blank glass, meeting the requirements for window transmittance; Thermal insulation performance: Infrared emissivity as low as 0.36, normal thermal conductivity 0.31 W / (m·K), with significant thermal insulation effect.

[0059] Example 4 This study investigates the comprehensive performance of the amorphous boron nitride thin film prepared in Example 1 under typical service conditions of marine equipment viewing windows, considering the coupling effect of different friction pairing materials with a complex marine environment. This aims to verify the film's practical engineering adaptability. Typical pairing materials easily accessible to viewing windows in the marine environment and their service conditions were selected for multi-factor coupling tests. Dual materials: Si3N4 sphere (Φ6 mm, simulating marine equipment ceramic sensor probe and precision observation component), 316L stainless steel sphere (Φ6 mm, simulating ship hull metal component). Environmental conditions: normal temperature, high humidity, and high salt spray environment (25 ℃, 85% RH, 5 wt% NaCl solution salt spray); low temperature, high humidity, and seawater immersion environment (0 ℃, 85% RH, 3.5 wt% NaCl solution immersion); high temperature, high humidity, and high salt spray environment (40 ℃, 85% RH, 5 wt% NaCl solution salt spray, simulating tropical marine climate).

[0060] The wear resistance of the thin film under different combinations of variables was tested according to the friction test method in Example 1, and the results are as follows: (1) Normal temperature high salt spray environment: Dual Si3N4 spheres: friction coefficient stable at 0.23, wear rate 0.26×10⁻⁶ -7 mm 3 ·N -1 ·m -1 ; Dual 316L stainless steel balls: coefficient of friction 0.26, wear rate 0.3×10⁻⁶ -7 mm 3 ·N -1 ·m -1 ; (2) Low-temperature seawater immersion environment: Dual Si3N4 ceramic balls: friction coefficient 0.25, wear rate 0.29×10⁻⁶ -7 mm 3 ·N -1 ·m -1 ; Paired 316L stainless steel balls: coefficient of friction 0.28, wear rate 0.33×10⁻⁶ -7 mm 3 ·N -1 ·m -1 ; (3) High temperature and high humidity salt spray environment: Dual Si3N4 ceramic balls: friction coefficient 0.22, wear rate 0.25×10⁻⁶ -7 mm 3 ·N -1 ·m -1 ; Dual 316L stainless steel balls: coefficient of friction 0.29, wear rate 0.36×10⁻⁶ -7 mm 3 ·N -1 ·m -1 ; The test results above show that the amorphous boron nitride thin film prepared in Example 1 maintains excellent wear resistance under different typical marine service environments and different coupling effects of paired materials, and the performance change law is highly consistent with the film structure characteristics and environmental action mechanism. The friction coefficient and wear rate of Si3N4 ceramic ball are consistently lower than those of 316L stainless steel ball, mainly due to the difference in their contact characteristics. Si3N4 ceramic ball has high hardness and forms a hard-hard contact with amorphous boron nitride thin film, resulting in a very low proportion of adhesive wear during friction, with only slight elastic deformation wear. In contrast, 316L stainless steel ball is a metal material and easily adheres to the film surface during friction, ultimately leading to an increase in friction coefficient and wear rate.

[0061] From the perspective of environmental conditions, the tribological performance of the low-temperature seawater immersion environment is slightly worse than that of the normal-temperature high-salt-spray environment. This is because at 0 ℃, the viscosity of the NaCl solution increases, the ionic activity decreases slightly, but the material brittleness increases, and the interfacial thermal stress between the film and the glass substrate increases slightly. This leads to a more pronounced stress concentration effect on the film surface during friction, resulting in a slight increase in the wear rate. Simultaneously, the corrosive-wear coupling effect of liquid seawater is stronger than that of gaseous salt spray, further exacerbating wear. However, in the high-temperature, high-humidity salt-spray environment, the wear resistance of the Si3N4 ceramic ball-paired film is slightly improved. This is due to the low thermal conductivity and low infrared emissivity of the amorphous boron nitride film, which effectively hinders the accumulation of frictional heat, reduces interfacial thermal stress, and avoids film softening caused by high temperatures. In contrast, the surface oxidation rate of the 316L stainless steel ball accelerates at high temperatures, and the oxide layer easily detaches to form abrasive particles, thus resulting in a more significant increase in the wear rate.

[0062] This embodiment verifies the good adaptability of amorphous boron nitride thin film to the typical service environment of marine equipment window glass through multi-factor coupling test. It not only clarifies the wear resistance performance of the film under different working conditions, but also provides comprehensive performance data support for the actual engineering application of the film. It is of great significance for promoting the large-scale application of the film in components such as marine observation windows and navigation equipment lenses.

[0063] Comparative Example 1 A method for preparing an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows is basically the same as that in Example 1, except that: Without the substrate pretreatment in step (1), the untreated marine equipment transparent tempered glass is directly placed into the reaction chamber of the magnetron sputtering instrument without ultra-cleaning and vacuum drying. The other steps are the same as in Example 1.

[0064] Compared with the amorphous boron nitride film prepared in Example 1, the film obtained in Comparative Example 1 showed a significant decrease in adhesion between the film and the substrate due to residual organic contaminants on the substrate surface; the film was prone to detachment during friction testing, the coefficient of friction increased to 0.5, and the wear rate increased to 1.8 × 10⁻⁶. -7 mm 3 ·N -1 ·m -1 The average visible light transmittance decreased to 78%–82%; corrosion resistance deteriorated significantly, and the self-corrosion current density increased to 5.76 × 10⁻⁶. -7 A·cm -2 This cannot meet the requirements of wear resistance, corrosion resistance and high transparency for marine equipment windows.

[0065] Comparative Example 2 A method for preparing an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows is basically the same as that in Example 1, except that: Without step (4) of substrate cleaning, after completing step (3) of vacuuming, proceed directly to step (5) of target cleaning, and the other steps are the same as in Example 1.

[0066] Compared with the amorphous boron nitride film prepared in Example 1, the film obtained in Comparative Example 2 had insufficient adhesion to the substrate due to the incomplete removal of the native oxide layer (SiO2) on the substrate surface; the surface roughness increased to 2.5~3 nm; the average visible light transmittance decreased to 83%~85%; and the wear resistance significantly decreased, with the wear rate increasing to 1.34×10⁻⁶. -7 mm 3 ·N -1 ·m -1 Corrosive media easily penetrate from the film-substrate interface, causing the self-corrosion current density to rise to 3.34 × 10⁻⁶. -7 A·cm -2 It cannot be stably adapted to the high salt spray environment of the ocean.

[0067] Comparative Example 3 A method for preparing an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows is basically the same as that in Example 1, except that: The target cleaning in step (5) is skipped. After completing the substrate cleaning in step (4), the thin film preparation in step (6) is carried out directly. The other steps are the same as in Example 1.

[0068] Compared with the amorphous boron nitride film prepared in Example 1, the film obtained in Comparative Example 3 had an impure amorphous structure due to the incomplete removal of the natural oxide layer (B2O3) on the surface of the hexagonal boron nitride target, resulting in impurities mixed into the film. XPS analysis showed that the B2O3 content increased to over 8 at%, and the corrosion resistance decreased significantly. After immersion in 3.5 wt% NaCl solution, obvious pitting corrosion appeared on the surface, and the self-corrosion potential increased to -0.47 V. The coefficient of friction increased to 0.32~0.35, and the wear rate increased to 1.93×10⁻⁶. -7 mm 3 ·N -1 ·m -1 It is impossible to achieve long-term wear-resistant protection for the windows of marine equipment.

[0069] Comparative Example 4 A method for preparing an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows is basically the same as that in Example 1, except that: In step (6), only argon gas (no nitrogen gas) is introduced during film preparation. Specifically, the argon gas flow rate is adjusted to 18 sccm, and no nitrogen gas is introduced (nitrogen partial pressure = 0 Pa). Other parameters are the same as in Example 1, and other steps are the same as in Example 1.

[0070] Compared with the amorphous boron nitride film prepared in Example 1, the film obtained in Comparative Example 4, due to insufficient nitrogen, had an imbalanced B / N atomic ratio of 1:0.7, making it impossible to form a complete amorphous boron nitride structure; its thermal insulation performance failed, the infrared emissivity in the 8-14 μm band increased to 0.75-0.8, and the normal thermal conductivity increased to 0.8-0.9 W / (m·K); the film was porous and had poor corrosion resistance, with the self-corrosion current density increasing to 1×10⁻⁶. -6 A·cm -2 Furthermore, the visible light transmittance drops to 80%~83%, making it impossible to meet the insulation and protection requirements of marine equipment windows.

[0071] Comparative Example 5 A method for preparing an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows is basically the same as that in Example 1, except that: Step (6) No bias voltage is applied during thin film preparation. Specifically, the substrate bias voltage is set to 0 V, and other parameters are the same as in Example 1. Other steps are the same as in Example 1.

[0072] Compared to the amorphous boron nitride film prepared in Example 1, the film obtained in Comparative Example 5, due to the lack of bias voltage to regulate the energy of deposited particles, has a loose structure and high internal stress, with a local thickness reduced to 150-160 nm. During friction, the film is prone to cracking, the friction coefficient increases to 0.32-0.35, and the wear rate increases to 0.93 × 10⁻⁶. -7 mm 3 ·N -1 ·m -1 Corrosive media easily penetrate through pores, causing the self-corrosion current density to rise to 3.53 × 10⁻⁶. -7 A·cm -2 The visible light transmittance fluctuates to 84%~86%, which cannot guarantee the observation accuracy and service life of marine equipment windows.

[0073] As can be seen from the above embodiments and comparative examples, this invention successfully prepared a pure amorphous boron nitride thin film on a glass substrate by precisely controlling key process parameters such as substrate pretreatment, substrate cleaning, target pre-sputtering, and argon flow rate, nitrogen partial pressure, radio frequency power, and substrate bias during the thin film deposition process. This thin film possesses excellent wear resistance, corrosion resistance, thermal insulation properties, and visible light transmittance, achieving a multi-functional synergistic effect, perfectly meeting the usage requirements of marine equipment viewing windows in harsh marine environments.

[0074] Compared with the comparative example, the technical solution of the present invention has the following significant features: substrate pretreatment and substrate cleaning ensure a strong bond between the film and the substrate; target pre-sputtering avoids impurity contamination and ensures the purity of the film; precisely controlled deposition parameters (especially argon flow rate of 15-20 sccm, nitrogen partial pressure of 0.1-0.5 Pa, RF power of 150-200 W, and substrate bias of 30-50 V) are key to obtaining an amorphous structure and excellent comprehensive performance. The absence of any key step or deviation from the key parameter range will lead to a significant decrease in film performance, making it impossible to achieve the synergistic unity of wear resistance, corrosion resistance, heat insulation, and high transparency.

Claims

1. A method for preparing an amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows, characterized in that, Includes the following steps: (1) Substrate pretreatment: Glass was selected as the substrate and was ultrasonically cleaned and dried in sequence with acetone, anhydrous ethanol and deionized water to obtain a clean glass substrate; (2) Target installation: A high-purity hexagonal boron nitride target is installed on the radio frequency power supply, with argon as the working gas and nitrogen as the supplementary nitrogen source to construct an amorphous boron nitride deposition system. (3) Vacuuming: Place the clean glass substrate obtained in step (1) into the reaction chamber of the magnetron sputtering instrument and perform vacuuming on the chamber; (4) Substrate cleaning: Inert gas is introduced into the chamber, substrate heating and substrate bias are turned on, and the glass substrate is cleaned by back sputtering. (5) Target pre-sputtering: Turn off the substrate bias, adjust the inert gas flow rate and chamber pressure, turn on the RF power supply to pre-sputter the hexagonal boron nitride target, and turn off the target baffle to prevent impurities from depositing on the glass substrate. (6) Thin film deposition: Adjust the mixing ratio of argon and nitrogen, the chamber pressure, turn on the RF power supply and substrate bias, set the substrate rotation speed, and deposit an amorphous boron nitride thin film on the glass substrate surface. In step (6), the argon flow rate is 15-20 sccm, the nitrogen partial pressure is 0.1-0.5 Pa, the RF power is 150-200 W, the substrate bias is 30-50 V, the deposition time is 2 hours, and the thickness of the amorphous boron nitride film is 180-200 nm.

2. The preparation method according to claim 1, characterized in that, The glass substrate mentioned in step (1) is transparent tempered glass for marine equipment, which is 20 mm long, 20 mm wide and 5 mm thick; the specific operation of ultrasonic cleaning is: the glass substrate is placed in acetone for 15 min, in anhydrous ethanol for 15 min and in deionized water for 15 min in sequence; the drying is to dry in a vacuum drying oven at 80 ℃ for 30 min.

3. The preparation method according to claim 1, characterized in that, The high-purity hexagonal boron nitride target mentioned in step (2) has a purity of ≥99.99%, a diameter of 50 mm, and a thickness of 4 mm.

4. The preparation method according to claim 1, characterized in that, The vacuuming process described in step (3) is as follows: first, a mechanical pump is used to evacuate to a vacuum level < 9 Pa, and then a molecular pump is switched to continue evacuating to a vacuum level < 1 × 10 Pa. -3 Pa, and the temperature of the reaction chamber is kept at room temperature during the vacuuming process.

5. The preparation method according to claim 1, characterized in that, The inert gas in step (4) is argon, with a flow rate of 50-100 sccm and a chamber pressure controlled at 5-10 Pa; the substrate heating temperature is 80 ℃, the substrate bias voltage is 300-500V, and the back sputtering time is 15 min.

6. The preparation method according to claim 1, characterized in that, The inert gas in step (5) is argon, with a flow rate of 20-30 sccm and a chamber pressure of 2-3 Pa; the power of the pre-sputtering RF power supply is 80-120 W and the pre-sputtering time is 15 min.

7. An amorphous boron nitride wear-resistant, corrosion-resistant, and heat-insulating film for marine equipment viewing windows, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 6.

8. The application of the amorphous boron nitride thin film according to claim 7 in the field of marine equipment, characterized in that, The applications include depositing the amorphous boron nitride thin film on the surface of marine equipment viewing windows for protection of marine observation windows, navigation equipment lenses, or instrument panel transparent covers.

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