Lightning-proof aircraft windshield glass with composite coating film and preparation method of lightning-proof aircraft windshield glass

Abstract

The invention discloses a lightning protection airplane windshield glass with a composite coating film and a preparation method thereof. A composite coating layer is arranged on the outer surface of outer-layer glass of the lightning-proof airplane windshield glass and comprises an ITO (indium tin oxide) conductive layer and a DLC (diamond-like carbon) wear-resistant layer covering the ITO conductive layer. And the ITO conducting layer is also conductively connected with a metal frame of the airplane body through a conducting assembly consisting of silver paste and a flexible tinned copper wire woven belt, so that a conducting path with low resistance and large current-carrying capacity is formed. Through the application of the composite coating film and the ITO + DLC composite coating film structure, the industrial problems of insufficient wear resistance (repeated scraping of a windshield wiper on the outer surface of the windshield glass) and insufficient weather resistance (salt fog resistance and the like) of a conductive layer on the outer surface of the windshield glass of an airplane are solved at one stroke, and lightning stroke current with the peak value of 200kA can be reliably discharged; the safety and reliability of the aircraft windshield glass are remarkably improved, the civil aviation airworthiness standard CCAR25.581 lightning protection is met, and a key technical solution is provided for the localization process of the civil aviation aircraft windshield glass.

Description

Technical Field

[0001] This invention relates to the field of aircraft windshield manufacturing technology, and in particular to a lightning protection aircraft windshield with a composite coating and its preparation method. Background Technology

[0002] Currently, both international aviation safety regulations (such as FAA AC 20-53B) and Chinese civil aviation airworthiness standards (such as CCAR-25.581) have incorporated lightning protection into the mandatory requirements for aircraft windshields. Statistics show that an aircraft may be struck by lightning once every 1,000 flight hours during its service life. As the point of contact for lightning strikes, the windshield must be able to withstand peak lightning currents of up to 200kA without damage. If the aircraft windshield lacks an effective lightning protection structure, lightning strikes may damage it, and the damaged area may expand during continued service, potentially leading to windshield failure. Therefore, developing an aircraft windshield that can withstand the friction and environmental corrosion of windshield wipers over a long period, and especially reliably discharge large lightning currents, has become a critical issue urgently needing to be addressed in this field.

[0003] In existing technologies, a single film structure has been considered for the outer surface of the windshield. However, such film structures often have limited hardness and insufficient wear resistance, making them unable to withstand the wiping action of windshield wipers for extended periods. Furthermore, prolonged exposure to flight environments (such as salt spray and high / low temperature cycling) makes them prone to oxidation and corrosion, leading to a sharp decline in conductivity and affecting their long-term reliability and service life. Even in the applicant's prior patent CN119142505A, a single antistatic coating layer is used on the outer surface of the aircraft windshield for lightning protection, which also suffers from insufficient wear resistance. This invention aims to solve this specific problem.

[0004] In particular, the main windshields of China's large civil aircraft are still imported, and domestic production has not yet been achieved. Even the maintenance and replacement needs of most currently in use civil aircraft still rely on imports. One of the technical challenges is the lack of effective and reliable lightning protection technology for aircraft main windshields. However, for the sake of supply chain security, China's civil aircraft manufacturing industry urgently needs to achieve the domestic production of main windshields for large civil aircraft. Summary of the Invention

[0005] In view of this, to solve the above problems, the purpose of this invention is to provide an innovative lightning-resistant aircraft windshield with a composite coating, comprising an outer glass layer, the outer surface of which is provided with a composite coating layer possessing conductivity, abrasion resistance, weather resistance, oxidation resistance, and optical properties; wherein, the composite coating layer comprises: an ITO conductive layer directly deposited on the outer surface of the outer glass layer, and a DLC abrasion-resistant layer deposited on the outer surface of the ITO conductive layer. Simultaneously, a low-resistance, high-current-carrying-capacity redundant conductive path is established between the ITO conductive layer in the composite coating and the aircraft's metal fuselage, for rapidly dispersing lightning currents with peak currents up to 200kA to the aircraft fuselage and releasing them through the aircraft's discharge brushes.

[0006] Preferably, the thickness of the ITO conductive layer is 100-200 nm, and the sheet resistance of the ITO conductive layer is 100-300 Ω / □; the thickness of the DLC wear-resistant layer is 10-20 nm.

[0007] Preferably, it further includes: a plurality of conductive components for forming a low-resistance, high-current-carrying-capacity redundant conductive path, wherein the ITO conductive layer is conductively connected to the metal frame of the aircraft fuselage through the plurality of conductive components.

[0008] Preferably, each of the conductive components includes: silver paste connected to the ITO conductive layer, and a flexible tin-plated copper wire braid connected to the silver paste, wherein the flexible tin-plated copper wire braid is conductively connected to the metal frame of the aircraft fuselage.

[0009] Preferably, it further includes: mounting an aluminum frame and a silicone rubber sealing strip, the silicone rubber sealing strip being disposed on the mounting aluminum frame, one end of the flexible tin-plated copper wire braided strip away from the silver paste being disposed close to the silicone rubber sealing strip, and the end of the flexible tin-plated copper wire braided strip being clamped between the silicone rubber sealing strip and the metal frame of the aircraft fuselage.

[0010] Preferably, the number of conductive components is at least four, and the four conductive components are distributed on the circumferential edge of the outer glass.

[0011] Preferably, it further includes: a first PU film layer, a middle glass layer, a second PU film layer, and an inner glass layer, wherein the outer glass layer, the first PU film layer, the middle glass layer, the second PU film layer, and the inner glass layer are stacked sequentially from the outside to the inside to form a laminated structure.

[0012] The present invention also aims to provide a composite coating for aircraft windshields, comprising: an ITO conductive layer deposited on a glass substrate; and a DLC wear-resistant layer deposited on the ITO conductive layer.

[0013] The present invention also aims to provide a method for preparing a lightning-resistant aircraft windshield with a composite coating as described in any one of the above-mentioned methods, comprising the following steps: step S1, depositing the ITO conductive layer on the outer surface of the outer glass using a magnetron sputtering process; step S2, depositing the DLC wear-resistant layer on the outer surface of the ITO conductive layer using a magnetron sputtering process.

[0014] Preferably, in step S1, the ITO conductive layer is first deposited on the outer surface of the outer glass, and then the flexible tin-plated copper wire braid is connected to the ITO conductive layer by silver paste.

[0015] The present invention, by adopting the above-mentioned technical solution, has the following positive effects compared with the prior art:

[0016] (1) An innovative composite coating layer that combines conductivity, wear resistance, weather resistance, oxidation resistance and optical performance, as well as a lightning protection aircraft windshield with the composite coating layer, is provided. It combines the high conductivity of ITO with the ultra-high hardness, wear resistance, low coefficient of friction and chemical inertness of DLC, so that the composite coating layer can withstand more than 100,000 repeated wiping by the wipers. After the composite coating has withstood 100,000 wear resistance cycles equivalent to the ASTM D4060 standard, its sheet resistance change rate does not exceed 10%, and it effectively resists the corrosion of salt spray and ultraviolet rays, fundamentally solving the durability problem.

[0017] (2) Reliable lightning protection performance: By using flexible tin-plated copper wire braided strip as a conductive component and connecting it with the ITO conductive layer with conductive silver paste, a redundant conductive path with low resistance, high current carrying capacity and high reliability is formed, which can ensure that the peak lightning current of 200kA is quickly discharged to the aircraft fuselage and can be released through the discharge brush, which greatly improves the flight safety of the aircraft.

[0018] (3) Promoting the localization of civil aircraft windshields: It effectively solves the technical bottleneck of lightning protection technology, which requires the outer surface of aircraft windshields to balance conductivity, wear resistance, weather resistance, oxidation resistance, and optical performance, meeting the civil aviation airworthiness standard "CCAR25.581 Lightning Protection". This provides a key technical solution for the localization of main windshields for large civil aircraft. In addition, it is also applicable to the lightning protection design of windshields for special aircraft, improving their flight safety. Attached Figure Description

[0019] Figure 1 A schematic diagram of an aircraft windshield with a composite coating for lightning protection provided by the present invention;

[0020] Figure 2 for Figure 1 A schematic diagram of the cross-section at point AA.

[0021] In the attached image:

[0022] 1. Inner glass layer; 2. Second PU film layer; 3. Middle glass layer; 4. First PU film layer; 5. Electrically heated ITO coating layer; 6. Outer glass layer; 7. Composite coating layer; 8. Horizontal PU film layer; 9. Stainless steel pressure frame; 10. Aviation bolt assembly; 11. Aramid fiber reinforced phenolic resin inner frame; 12. PR-1425 aviation-grade waterproof sealant layer; 13. First aramid fiber reinforced phenolic resin frame; 14. Second aramid fiber reinforced phenolic resin frame; 15. Flexible tin-plated copper wire braided strip; 16. Silicone rubber sealing strip; 17. Mounting aluminum frame; 18. Vertical PU film layer. Detailed Implementation

[0023] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In the description of this invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "lateral", and "vertical" are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be construed as a limitation of this invention.

[0025] It should be noted that the terms "horizontal" and "vertical" in this invention are used to describe approximate positional relationships, and not strictly "horizontal plane" or "vertical plane".

[0026] like Figure 1 and Figure 2 The image illustrates a preferred embodiment of a lightning-resistant aircraft windshield with a composite coating. The windshield includes an outer glass layer 6, on which a composite coating layer 7, possessing conductivity, abrasion resistance, weather resistance, oxidation resistance, and optical properties, is prepared using a magnetron sputtering process. The composite coating layer 7 comprises an ITO (indium tin oxide) conductive layer directly deposited on the outer surface of the outer glass layer 6, and a DLC (diamond-like carbon) abrasion-resistant layer deposited on the outer surface of the ITO conductive layer. Furthermore, by setting the two-layer composite coating layer 7 (ITO + DLC) on the lightning-resistant aircraft windshield and cooperating with corresponding conductive components, the lightning protection requirements of the aircraft windshield are achieved.

[0027] Furthermore, in a preferred embodiment, the thickness of the ITO conductive layer is 100-200 nm, and its sheet resistance is 100-300 Ω / □; the thickness of the DLC wear-resistant layer is 10-20 nm. More specifically, the thickness of the ITO conductive layer is preferably 150 nm, and its sheet resistance is 200 Ω / □; the thickness of the DLC wear-resistant layer is preferably 20 nm.

[0028] Furthermore, as a preferred embodiment, it also includes: a plurality of conductive components for forming a low-resistance, high-current-carrying-capacity redundant conductive path, wherein the ITO conductive layer is electrically connected to the metal frame of the aircraft fuselage through the plurality of conductive components.

[0029] Furthermore, in a preferred embodiment, each conductive component includes: silver paste bonded to the ITO conductive layer, and a flexible tin-plated copper wire braid 15 bonded to the silver paste, wherein the flexible tin-plated copper wire braid 15 is conductively connected to the metal frame of the aircraft fuselage. Furthermore, the ITO conductive layer and the flexible tin-plated copper wire braid 15 are electrically bonded together using silver paste.

[0030] Furthermore, as a preferred embodiment, it further includes: an aluminum frame 17 and a silicone rubber sealing strip 16, wherein the silicone rubber sealing strip 16 is disposed on the aluminum frame 17, and one end of the flexible tin-plated copper wire braided strip 15 away from the silver paste is disposed near the silicone rubber sealing strip 16, and the end of the flexible tin-plated copper wire braided strip 15 is clamped between the silicone rubber sealing strip 16 and the metal frame of the aircraft fuselage. Furthermore, when this lightning protection aircraft windshield is installed on the aircraft fuselage via the aluminum frame 17, the end of the flexible tin-plated copper wire braided strip 15 is pressed tightly against the metal frame of the aircraft fuselage by the silicone rubber sealing strip 16, thereby establishing a low-resistance, high-current-carrying conductive path from the composite coating layer 7 to the metal structure of the aircraft fuselage.

[0031] Furthermore, as a preferred embodiment, the mounting aluminum frame 17 is fixedly connected to the aircraft fuselage by corresponding aviation bolts, specifically preferably at the nose of the aircraft.

[0032] Furthermore, as a preferred embodiment, the aircraft fuselage is also equipped with corresponding discharge brushes to release the lightning current. Furthermore, the composite coating layer 7, conductive components, the metal frame of the aircraft fuselage, and the discharge brushes together form a discharge path for the lightning current.

[0033] Furthermore, as a preferred embodiment, the number of conductive components is at least four, and the four conductive components are distributed along the circumferential edge of the outer glass 6. More preferably, the number of conductive components is eight, which are arranged relatively evenly along the circumference of the mounting aluminum frame 17.

[0034] Furthermore, as a preferred embodiment, it also includes: a first PU film layer 4, a middle glass layer 3, a second PU film layer 2 and an inner glass layer 1, with the outer glass layer 6, the first PU film layer 4, the middle glass layer 3, the second PU film layer 2 and the inner glass layer 1 stacked sequentially from the outside to the inside to form a laminated structure.

[0035] Furthermore, as a preferred embodiment, an electrically heated ITO coating layer 5 is also provided on the inner surface of the outer glass 6. Furthermore, the electrically heated ITO coating layer 5 enables de-icing and defogging of the lightning-resistant aircraft windshield with the composite coating.

[0036] Furthermore, in a preferred embodiment, the outer edge of the laminated structure is provided with an edge sealing structure. This edge sealing structure includes: a first aramid fiber reinforced phenolic resin frame 13, a transverse PU film layer 8, and a second aramid fiber reinforced phenolic resin frame 14 arranged sequentially along the thickness direction; and the edge sealing structure is bonded to the circumferential edge of the laminated structure via a longitudinal PU film layer 18. Further, the first aramid fiber reinforced phenolic resin frame 13 is positioned close to the inner glass layer 1, and the second aramid fiber reinforced phenolic resin frame 14 is positioned close to the outer glass layer 6; the edge sealing structure achieves a waterproof and vapor-proof seal for the lightning-resistant aircraft windshield with the composite coating.

[0037] Furthermore, as a preferred embodiment, the contact points between the aforementioned PU film layer and other structures are preferably fully sealed using a PR-1425 aviation-grade waterproof sealant layer 12. Further, the PR-1425 aviation-grade waterproof sealant layer 12 at least surrounds the inner and outer sides of the sealing structure, and preferably also surrounds the inner and outer sides of the edge of the laminated structure.

[0038] Furthermore, as a preferred embodiment, it further includes: an aramid fiber reinforced phenolic resin inner frame 11, the aramid fiber reinforced phenolic resin inner frame 11 and the mounting aluminum frame 17 are respectively stacked on the inner and outer sides of the PR-1425 aviation-grade waterproof sealant layer 12 and bonded to the PR-1425 aviation-grade waterproof sealant layer 12; wherein, the aramid fiber reinforced phenolic resin inner frame 11 is disposed close to the inner glass layer 1, and the mounting aluminum frame 17 is disposed close to the outer glass layer 6.

[0039] Furthermore, as a preferred embodiment, it also includes: a stainless steel pressure frame 9, which is disposed between the edge sealing structure and the mounting aluminum frame 17, and a PR-1425 aviation-grade waterproof sealant layer 12 is also surrounding the outside of the stainless steel pressure frame 9.

[0040] Furthermore, as a preferred embodiment, it also includes: an aviation bolt assembly 10, which sequentially connects from the inside out to the inner part of the aramid fiber reinforced phenolic resin inner frame 11, the inner part of the PR-1425 aviation-grade waterproof sealant layer 12, the first aramid fiber reinforced phenolic resin frame 13, the transverse PU film layer 8, the second aramid fiber reinforced phenolic resin frame 14, the outer part of the PR-1425 aviation-grade waterproof sealant layer 12, the stainless steel pressure frame 9, and the mounting aluminum frame 17, thereby achieving connection and reinforcement between the various edge sealing structures, laminated structures, and surrounding materials.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the implementation and protection scope of the present invention.

[0042] In addition to the above, the present invention also has the following embodiments:

[0043] In a further embodiment of the present invention, a composite coating for aircraft windshields includes: an ITO conductive layer deposited on a glass substrate; and a DLC abrasion-resistant layer deposited on the ITO conductive layer; the composite coating exhibits a sheet resistance change rate of no more than 10% after undergoing 100,000 abrasion cycles equivalent to the ASTM D4060 standard.

[0044] In a further embodiment of the present invention, a method for preparing a lightning-resistant aircraft windshield with a composite coating as described above includes the following steps: Step S1, depositing an ITO conductive layer on the outer surface of the outer glass 6 using a magnetron sputtering process; Step S2, depositing a DLC wear-resistant layer on the outer surface of the ITO conductive layer using a magnetron sputtering process.

[0045] In a further embodiment of the present invention, in step S1, an ITO conductive layer is first deposited on the outer surface of the outer glass 6, and then the flexible tin-plated copper wire braided strip 15 is connected to the ITO conductive layer by silver paste, and then the DLC wear-resistant layer is formed in step S2.

[0046] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A lightning strike resistant aircraft windshield glass having a composite coating, comprising an outer glass, characterized in that, An outer surface of the outer layer glass is provided with a composite coating layer; The composite coating layer comprises an ITO conductive layer deposited directly on the outer surface of the outer layer glass, and a DLC wear-resistant layer deposited on the outer surface of the ITO conductive layer.

2. The lightning-protected aircraft windshield glass having a composite plating film according to claim 1, wherein, The thickness of the ITO conductive layer is 100-200 nm, and the sheet resistance of the ITO conductive layer is 100-300 Ω / □; the thickness of the DLC wear-resistant layer is 10-20 nm.

3. The lightning-protected aircraft windshield glass with a composite coating according to claim 1, characterized in that, Further comprising: A plurality of conductive components, the ITO conductive layer being conductively connected to the metal frame of the aircraft body through the plurality of conductive components.

4. The lightning-protected aircraft windshield glass with a composite coating according to claim 3, characterized in that, Each of the conductive components comprises silver paste connected to the ITO conductive layer, and a flexible tinned copper wire braid connected to the silver paste, the flexible tinned copper wire braid being conductively connected to the metal frame of the aircraft body.

5. The lightning-protected aircraft windshield glass with a composite coating according to claim 4, characterized in that, Further comprising: An installation aluminum frame and a silicone rubber sealing strip, the silicone rubber sealing strip being arranged on the installation aluminum frame, an end of the flexible tinned copper wire braid away from the silver paste being arranged close to the silicone rubber sealing strip, when the lightning protection aircraft windshield glass is installed on the aircraft body through aviation bolts, the end of the flexible tinned copper wire braid being clamped and compressed between the silicone rubber sealing strip and the metal frame of the aircraft body.

6. The lightning-protected aircraft windshield glass with a composite coating according to claim 3, characterized in that, The number of the conductive components is at least four, and the four conductive components are distributed on the circumferential edge of the outer layer glass.

7. The lightning-protected aircraft windshield glass with a composite coating according to claim 1, characterized in that, Further comprising: A first PU film layer, a middle layer glass, a second PU film layer, and an inner layer glass, the outer layer glass, the first PU film layer, the middle layer glass, the second PU film layer, and the inner layer glass being sequentially stacked from outside to inside to form a laminated structure.

8. A composite coating for aircraft windshield glass, characterized by, Comprising: An ITO conductive layer deposited on a glass substrate; And a DLC wear-resistant layer deposited on the ITO conductive layer; the composite coating layer has a sheet resistance change rate of no more than 10% after undergoing 1 million times of wear resistance test equivalent to the standard of ASTM D4060.

9. A method of manufacturing a lightning-protected aircraft windshield glass having a composite plating film according to any one of claims 1 to 7, characterized by, Comprising the following steps: Step S1, depositing the ITO conductive layer on the outer surface of the outer layer glass by using a magnetron sputtering process; Step S2, depositing the DLC wear-resistant layer on the outer surface of the ITO conductive layer by using a magnetron sputtering process.

10. The method of claim 9, wherein, In the step S1, the ITO conductive layer is first deposited on the outer surface of the outer layer glass, and then a flexible tinned copper wire braid is connected to the ITO conductive layer through silver paste.

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