An interface reinforcement gradient design method for impact-resistant aviation glass laminated structure

Abstract

The present invention discloses an interface reinforcement gradient design method for an impact-resistant aviation glass laminate structure. The present invention relates to the field of composite material design technology, including glass material preparation, interface reinforcement gradient design, lamination, quality inspection and performance testing. The glass material includes glass layer material, intermediate layer material and transition layer material. The lamination process includes pre-strain treatment, pre-pressing treatment, hot pressing bonding and cooling demolding. The advantage of the present invention is that by providing transition layers with gradient changes in composition and performance, the content of reinforcing materials such as nano-titanium dioxide particles and graphene nanosheets in each transition layer is gradually increased, so that the elastic modulus, thermal expansion coefficient and other properties of the material are smoothly transitioned between layers. Compared with traditional uniform or simple layered structures, the gradient design significantly reduces the interface stress concentration phenomenon caused by performance differences between the glass layer and the polymer intermediate layer.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material design, in particular to an interface reinforcement gradient design method for an impact-resistant aviation glass laminate structure. Background Art

[0002] In the aerospace field, aviation glass, as a key component isolating the aircraft cabin from the outside world, not only maintains stable cabin pressure and ensures a clear field of vision for pilots, but also needs to withstand extreme external forces such as high-speed airflow and bird strikes. Its impact resistance directly affects flight safety and the lives of occupants. To meet these stringent performance requirements, laminated aviation glass, which combines multiple layers of materials such as glass and polymers, leverages the properties of each layer to synergistically enhance overall performance, becoming the mainstream structural form of aviation glass.

[0003] However, the existing aviation glass laminate structure has significant deficiencies in interface design. Traditional designs mostly adopt uniform structures or simple layered structures. The differences in physical and chemical properties between different material layers can easily lead to interface stress concentration. The glass layer and the polymer interlayer have large differences in elastic modulus, thermal expansion coefficient, etc. When subjected to impact or temperature changes, stress concentration will occur at the interface, causing the interface to be damaged first, thereby weakening the impact resistance of the aviation glass. In addition, the existing design lacks effective means to enhance the interface performance. It is difficult for the various layers of materials to fully exert the synergistic effect and cannot meet the increasingly stringent safety standards and performance requirements in the aviation field. To this end, we propose an interface enhancement gradient design method for impact-resistant aviation glass laminate structures. Summary of the Invention

[0004] The object of the present invention is to provide a method for designing an interface reinforcement gradient of an impact-resistant aviation glass laminate structure.

[0005] To achieve the above objectives, the present invention provides the following technical solutions: a method for designing an interface enhancement gradient for an impact-resistant aviation glass laminate structure, comprising glass material preparation, interface enhancement gradient design, lamination, quality inspection, and performance testing. The glass material comprises a glass layer material, an intermediate layer material, and a transition layer material. The lamination process comprises pre-strain treatment, pre-pressing treatment, hot pressing bonding, and cooling demolding. The specific operating steps of the interface enhancement gradient design method for an impact-resistant aviation glass laminate structure are as follows:

[0006] Step 1: Select microcrystalline glass as the glass layer material, cut and clean it for later use. The middle layer material is made of a mixture of ethylene-vinyl acetate copolymer, polydimethylsiloxane and thermoplastic polyurethane. The first layer of the transition layer material is based on polyetheretherketone, and is added with nano-titanium dioxide particles, graphene nanosheets, shape memory alloy microfilaments and ultra-high molecular weight polyethylene fibers;

[0007] Step 2: Assemble and stack the glass layer material, the intermediate layer material, and the transition layer material in order;

[0008] Step 3: Pre-strain the transition layer material before lamination, pre-press to remove air between layers after the treatment, and cool and demould after hot pressing to obtain the finished aviation glass product;

[0009] Step 4: Conduct quality inspection on the finished aviation glass products, including appearance inspection and mechanical property testing. The mechanical property testing includes tensile testing, drop hammer impact testing and fatigue testing.

[0010] As a further solution of the present invention: the transition layer material includes a first transition layer, a second transition layer, a third transition layer, a fourth transition layer and a polymer gradient interlayer, the content of nano-titanium dioxide particles in the second transition layer, the third transition layer and the fourth transition layer are 12%, 16% and 20% respectively, the content of graphene nanosheets are 0.5%, 0.8% and 1% respectively, the content of shape memory alloy microfilaments are 3%, 4% and 5% respectively, the content of carbon nanofibers are 1%, 2% and 3% respectively, and the content of ultra-high molecular weight polyethylene fibers are 1.5%, 2% and 2.5% respectively.

[0011] As a further solution of the present invention: the polymer gradient interlayer is based on polymethyl methacrylate and doped with nano-silica particles. The specific preparation steps are:

[0012] The polymethyl methacrylate was dried at a temperature of 80°C-85°C for 4 hours, and then transferred into a high-speed mixer with nano-silica particles and stirred at a speed of 1000r / min-1200r / min for 30 minutes. After the stirring was completed, the mixture was placed in a hot pressing mold and hot pressed at a temperature of 160°C and a pressure of 5MPa for 15min-20min to form an organic polymer gradient interlayer with a thickness of 0.4mm.

[0013] As a further solution of the present invention: in the step one, a microcrystalline glass with a thickness of 3 mm is selected, and a high-precision laser cutting machine is used to cut the microcrystalline glass into 500 mm × 500 mm square plates, and the magnetorheological polishing technology is used to polish the glass surface, and the surface roughness is controlled at Ra0.02 μm. The edge of the glass is chamfered at 45° using a CNC edge grinding machine, and the chamfer width is 0.3 mm. After the treatment is completed, it is transferred to a plasma cleaning machine, the power is set to 150 W, and after cleaning for 5 minutes to 10 minutes, a microcrystalline glass layer is obtained, which is the glass layer material.

[0014] As a further solution of the present invention: in the step one, the three layers of composite material are ethylene-vinyl acetate copolymer, polydimethylsiloxane and thermoplastic polyurethane from the outside to the inside, respectively. The three layers of material represent the outer layer, the middle layer and the inner layer, respectively. The thicknesses of the three layers of material are 0.2 mm, 0.36 mm and 0.2 mm, respectively. In a clean environment with a temperature of 22°C and a humidity of 25%, a precision cutting machine is used to cut the composite middle layer into a size of 510 mm × 510 mm. After completion, it is transferred to a vacuum drying oven and dried at a temperature of 35°C for 6 hours to obtain a composite middle layer, which is the middle layer material.

[0015] As a further solution of the present invention: In the step one, the first transition layer is based on polyetheretherketone, and 8% by mass of nano-titanium dioxide particles, 0.3% by mass of graphene nanosheets, 2% by mass of shape memory alloy microfilaments, and 1% by mass of ultra-high molecular weight polyethylene fibers are added. The mixture is blended using a twin-screw extruder, the extrusion temperature is set to 380°C, the screw speed is 80r / min-100r / min, and a hot pressing molding process is used to press it into a 0.12mm-0.13mm thick film at a temperature of 360°C-380°C and a pressure of 5MPa. The film has a size of 505mm×505mm. After molding, it is placed in a clean environment at 25°C for annealing at an annealing temperature of 180°C and kept warm for 2h-3h to obtain the first transition layer.

[0016] As a further solution of the present invention: in the step 2, the layers are stacked in the order of microcrystalline glass layer-first transition layer-organic polymer gradient interlayer-second transition layer-organic polymer gradient interlayer-third transition layer-organic polymer gradient interlayer-fourth transition layer-composite intermediate layer-fourth transition layer-organic polymer gradient interlayer-third transition layer-organic polymer gradient interlayer-second transition layer-organic polymer gradient interlayer-first transition layer-microcrystalline glass layer, and the interlayer misalignment error is controlled between ±0.05mm. Femtosecond laser processing technology is used to process a groove structure with a depth of 50nm-100nm and a spacing of 200nm-300nm on the surface of the first transition layer, a columnar structure with a diameter of 1μm-2μm and a height of 3μm-5μm is processed in the second transition layer, a porous structure with a pore diameter of 200nm-500nm and a porosity of 10%-15% is processed in the third transition layer, and a composite gradient structure is processed in the fourth transition layer.

[0017] As a further solution of the present invention: In the step three, the transition layer material is fixed on a stretching device and pre-stretched at a speed of 0.5 mm / min. The pre-stretching strain of the first transition layer is controlled at 5%, the second transition layer is 6%, the third transition layer is 7%, and the fourth transition layer is 8%. The pre-stretching is maintained for 10 minutes, and the stress is slowly released after completion.

[0018] As a further solution of the present invention: In the step three, the pre-strained material is placed in a vacuum hot pressing molding machine, and pre-pressed for 12 minutes to 15 minutes at a temperature of 75°C and a pressure of 0.6 MPa. During the pre-pressing process, the vacuum degree is maintained at -0.095 MPa. The hot pressing is combined with heating to 155°C at a rate of 1.5°C / min, and the pressure is increased to 4.5 MPa. At the same time, ultrasonic waves with a frequency of 25kHz and a power of 600W and a pulsed magnetic field with an intensity of 0.5T are applied, the pulse frequency is 10Hz, and the pressure and magnetism are maintained for 13 minutes to 15 minutes. After the hot pressing is completed, the temperature is cooled to 60°C at a rate of 1°C / min. After the cooling is completed, the pressure is slowly released and the mold is demolded, and the demolding force is controlled to be 50N-80N to obtain a finished aviation glass product.

[0019] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The present invention provides transition layers with gradient composition and properties. The content of reinforcing materials such as nano-titanium dioxide particles and graphene nanosheets in each transition layer gradually increases, resulting in a smooth transition between layers in terms of elastic modulus, thermal expansion coefficient, and other properties. Compared to traditional uniform or simple layered structures, the gradient design significantly reduces interfacial stress concentration caused by performance differences between the glass layer and the polymer interlayer. When the aviation glass is subjected to impact or temperature changes, the gradient transition layer effectively disperses stress, preventing damage at the interface, significantly improving the stability and reliability of the aviation glass structure.

[0021] 2. The present invention enhances the mechanical interlocking effect between layers by combining multiple high-performance materials in the transition layer and designing different microstructures for each layer. Furthermore, the polymer gradient interlayer, based on polymethyl methacrylate and doped with nano-silica particles, synergizes with the transition layer, enabling each layer to fully utilize its own unique characteristics and achieve complementary performance. When subjected to external forces, the layers cooperate and deform synergistically, significantly improving the overall impact resistance of aviation glass and meeting the safety standards and performance requirements of the aviation field.

[0022] 3. The present invention pre-stresses the transition layer material to a pre-stressed state, enabling it to better absorb and disperse energy when subsequently subjected to stress. The precisely controlled temperature, pressure, time and other parameters during the pre-pressing and hot-pressing process, combined with the auxiliary effects of ultrasound and pulsed magnetic fields, promote molecular diffusion and fusion between materials, ensure the orderly arrangement of shape memory alloy microwires, make the laminated structure denser, and enhance the mechanical properties and fatigue resistance of aviation glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a flow chart of the interface enhancement gradient design method in an embodiment of the present invention;

[0024] Figure 2 This is a comparison chart of thermal cycle and bird strike test data in an embodiment of the present invention;

[0025] Figure 3 A comparison chart of chemical corrosion resistance test data in an embodiment of the present invention;

[0026] Figure 4 2 is a comparison chart of dynamic mechanical analysis test data in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0028] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] Please see the attached Figure 1 -Attached Figure 4 The present invention provides a method for designing an interface enhancement gradient for an impact-resistant aviation glass laminate structure, including glass material preparation, interface enhancement gradient design, lamination, quality inspection, and performance testing. The glass material includes a glass layer material, an intermediate layer material, and a transition layer material. The lamination process includes pre-strain treatment, pre-pressing treatment, hot pressing bonding, and cooling demolding. The specific steps of the interface enhancement gradient design method for an aviation glass laminate structure are as follows:

[0030] Step 1: Select microcrystalline glass as the glass layer material, cut and clean it for later use. The middle layer material is made of a mixture of ethylene-vinyl acetate copolymer, polydimethylsiloxane and thermoplastic polyurethane. The first layer of the transition layer material is based on polyetheretherketone, and is added with nano-titanium dioxide particles, graphene nanosheets, shape memory alloy microfilaments and ultra-high molecular weight polyethylene fibers;

[0031] Step 2: Assemble and stack the glass layer material, the intermediate layer material, and the transition layer material in order;

[0032] Step 3: Pre-strain the transition layer material before lamination, pre-press to remove air between layers after the treatment, and cool and demould after hot pressing to obtain the finished aviation glass product;

[0033] Step 4: Conduct quality inspection on the finished aviation glass products, including appearance inspection and mechanical property testing. The mechanical property testing includes tensile testing, drop hammer impact testing and fatigue testing.

[0034] In one embodiment of the present invention: the transition layer material includes a first transition layer, a second transition layer, a third transition layer, a fourth transition layer and a polymer gradient interlayer, the content of nano-titanium dioxide particles in the second transition layer, the third transition layer and the fourth transition layer are 12%, 16% and 20% respectively, the content of graphene nanosheets are 0.5%, 0.8% and 1% respectively, the content of shape memory alloy microfilaments are 3%, 4% and 5% respectively, the content of carbon nanofibers are 1%, 2% and 3% respectively, and the content of ultra-high molecular weight polyethylene fibers are 1.5%, 2% and 2.5% respectively.

[0035] In one embodiment of the present invention, the polymer gradient interlayer is based on polymethyl methacrylate and doped with nano-silica particles. The specific preparation steps are as follows:

[0036] The polymethyl methacrylate was dried at a temperature of 80°C-85°C for 4 hours, and then transferred into a high-speed mixer with nano-silica particles and stirred at a speed of 1000r / min-1200r / min for 30 minutes. After the stirring was completed, the mixture was placed in a hot pressing mold and hot pressed at a temperature of 160°C and a pressure of 5MPa for 15min-20min to form an organic polymer gradient interlayer with a thickness of 0.4mm.

[0037] In one embodiment of the present invention: in step one, a microcrystalline glass with a thickness of 3 mm is selected, and a high-precision laser cutting machine is used to cut the microcrystalline glass into 500 mm × 500 mm square plates, and the magnetorheological polishing technology is used to polish the glass surface, and the surface roughness is controlled at Ra0.02 μm. The glass edge is chamfered at 45° using a CNC edge grinding machine, and the chamfer width is 0.3 mm. After the treatment is completed, it is transferred to a plasma cleaning machine, the power is set to 150 W, and after cleaning for 5 minutes to 10 minutes, a microcrystalline glass layer is obtained, which is the glass layer material.

[0038] In one embodiment of the present invention: in step one, the three layers of composite material are ethylene-vinyl acetate copolymer, polydimethylsiloxane and thermoplastic polyurethane from the outside to the inside, respectively. The three layers of material represent the outer layer, the middle layer and the inner layer, respectively. The thicknesses of the three layers of material are 0.2 mm, 0.36 mm and 0.2 mm, respectively. In a clean environment with a temperature of 22°C and a humidity of 25%, a precision cutting machine is used to cut the composite middle layer into a size of 510 mm × 510 mm. After completion, it is transferred to a vacuum drying oven and dried at a temperature of 35°C for 6 hours to obtain a composite middle layer, which is the middle layer material.

[0039] In one embodiment of the present invention: in step one, the first transition layer is based on polyetheretherketone, and 8% by mass of nano-titanium dioxide particles, 0.3% by mass of graphene nanosheets, 2% by mass of shape memory alloy microfilaments, and 1% by mass of ultra-high molecular weight polyethylene fibers are added. A twin-screw extruder is used to blend them, and the extrusion temperature is set to 380°C, the screw speed is 80r / min-100r / min, and a hot pressing molding process is used to press them into a 0.12mm-0.13mm thick film at a temperature of 360°C-380°C and a pressure of 5MPa. The size is 505mm×505mm. After molding, it is placed in a clean environment at 25°C for annealing, the annealing temperature is 180°C, and the first transition layer is obtained after keeping warm for 2h-3h.

[0040] In one embodiment of the present invention: in step 2, the layers are stacked in the order of glass-ceramic layer-first transition layer-organic polymer gradient interlayer-second transition layer-organic polymer gradient interlayer-third transition layer-organic polymer gradient interlayer-fourth transition layer-composite intermediate layer-fourth transition layer-organic polymer gradient interlayer-third transition layer-organic polymer gradient interlayer-second transition layer-organic polymer gradient interlayer-first transition layer-glass-ceramic layer, and the interlayer misalignment error is controlled between ±0.05mm. Femtosecond laser processing technology is used, and the laser power is set to 600mW-900mW and the wavelength is 600nm. -800nm, pulse width of 120fs-150fs, repetition frequency of 220kHz-250kHz, scanning speed of 3μm / s-100μm / s and irradiation time of 2s-10s, groove structure with a depth of 50nm-100nm and a spacing of 200nm-300nm is processed on the surface of the first transition layer, and a columnar structure with a diameter of 1μm-2μm and a height of 3μm-5μm is processed on the second transition layer. A porous structure with a pore size of 200nm-500nm and a porosity of 10%-15% is processed in the third transition layer, and a composite gradient structure is processed in the fourth transition layer.

[0041] In one embodiment of the present invention: in step three, the pre-strained material is placed in a vacuum hot pressing molding machine, pre-pressed for 12 minutes to 15 minutes at a temperature of 75°C and a pressure of 0.6 MPa, and the vacuum degree is maintained at -0.095 MPa during the pre-pressing process. The hot pressing is combined with heating to 155°C at a rate of 1.5°C / min, and the pressure is increased to 4.5 MPa. At the same time, ultrasonic waves with a frequency of 25kHz and a power of 600W and a pulsed magnetic field with an intensity of 0.5T are applied, the pulse frequency is 10Hz, and the pressure and magnetism are maintained for 13 minutes to 15 minutes. After the hot pressing is completed, the temperature is cooled to 60°C at a rate of 1°C / min. After the cooling is completed, the pressure is slowly released and the mold is demolded, and the demolding force is controlled to be 50N-80N to obtain an aviation glass product.

[0042] In one embodiment of the present invention: in step three, the transition layer material is fixed on a stretching device and pre-stretched at a speed of 0.5 mm / min. The pre-stretching strain of the first transition layer is controlled at 5%, the second transition layer is 6%, the third transition layer is 7%, and the fourth transition layer is 8%. The pre-stretching is maintained for 10 minutes, and the stress is slowly released after completion, in order to provide an initial stress state for subsequent pre-compression.

[0043] In one embodiment of the present invention, in step 1, the main crystalline phases in the glass-ceramics are wollastonite and diopside, with a density of 2.6 g / cm³, an elastic modulus of 85 GPa, and a thermal expansion coefficient of 8×10 -6 / K, with excellent thermal shock resistance;

[0044] In one embodiment of the present invention: in step 1, the content of nano-titanium dioxide particles in the second transition layer is increased to 12%, the content of graphene nanosheets is increased to 0.5%, the content of shape memory alloy microfilaments is changed to 3%, the content of carbon nanofibers is 1%, and the content of ultra-high molecular weight polyethylene fibers is increased to 1.5%. At the same time, aerogel particles are uniformly dispersed in the material, and the other preparation process parameters remain unchanged to prepare a 0.16 mm thick film. The content of nano-titanium dioxide particles in the third transition layer is 16%, the content of graphene nanosheets is 0.8%, the content of shape memory alloy microfilaments is 4%, and the content of carbon nanofibers is 1%. The content of rice fiber is 2%, the content of ultra-high molecular weight polyethylene fiber is 2%, and the volume fraction of aerogel particles is increased to 8%, making a 0.22mm thick film. The content of nano-titanium dioxide particles in the fourth transition layer is 20%, the content of graphene nanosheets is 1%, the content of shape memory alloy microfilaments is 5%, the content of carbon nanofibers is 3%, the content of ultra-high molecular weight polyethylene fiber is 2.5%, and the volume fraction of aerogel particles is 10%, making a 0.28mm thick film. After the preparation of each transition layer film, it is left to stand in an environment with a temperature of 23°C and a humidity of 20% for 48 hours to make the material properties fully stable.

[0045] In one embodiment of the present invention, in step 1, the organic polymer gradient interlayer can be replaced with a nanocomposite gel interlayer. A 2% by mass sodium alginate aqueous solution and a 1% by mass calcium chloride aqueous solution are prepared respectively. Different amounts of nanocellulose with a diameter of 5 nm to 10 nm and a length of 100 nm to 500 nm are added to the sodium alginate aqueous solution, stirred evenly, and the mixed solutions of different concentrations are poured into a mold by a layer-by-layer casting method. The mixture is allowed to stand at room temperature for 2 hours to form a gel, thereby obtaining a transparent interlayer with a thickness of 0.4 mm and a nanocellulose content gradually varying from 0.5% near the glass layer to 2% near the middle layer. The interlayer is then cut into corresponding sizes for later use.

[0046] In one embodiment of the present invention, in step 2, the characteristics of the shape memory alloy microwires are utilized to impart a shape memory function gradient at different temperatures to the transition layer. The phase transition temperature of the shape memory alloy microwires in the transition layer close to the micro-glass layer can reach 60°C-70°C. As it transitions to the middle layer, the phase transition temperature gradually decreases to 40°C-50°C, thereby achieving a gradient stress adjustment function under different temperature environments. At the same time, the aerogel particles and the newly added transparent interlayer material exert a gradient buffering and energy absorption effect under different impact intensities through their own elastic deformation, nanoparticles, and nanocellulose. The aerogel particles can reduce the overall thermal conduction efficiency of the product, improve high temperature resistance and thermal stability, and at the same time enhance the impact resistance and vibration resistance of the transition layer, thereby reducing interlayer stress concentration.

[0047] In one embodiment of the present invention, in step 4, the appearance inspection is performed using a scanning electron microscope with a magnification of 5000 times and an optical interferometer to inspect the glass surface and the interface between layers. The surface must be free of scratches and cracks, the interface must be free of bubbles and impurities, the interface must be smooth, and there must be no obvious delamination. At the same time, it must be ensured that the newly added transparent interlayer is free of problems such as fogging and discoloration that affect transparency.

[0048] Mechanical properties test,

[0049] Tensile test: Dumbbell-shaped specimens with a size of 120 mm × 25 mm were cut from the prepared aviation glass. The interfacial tensile strength was tested on an electronic universal material testing machine at a tensile speed of 4 mm / min. The average value was required to be no less than 25 MPa.

[0050] Drop hammer impact test: A 1.2kg steel ball is dropped freely from a height of 1.2m to impact the center of the glass surface. The glass is required to have no penetrating damage, only local cracks, and the crack extension length does not exceed 40mm. A high-speed camera is used to record the crack growth during the impact process.

[0051] Fatigue test: Cyclic loads are applied to the specimens, with a load range of 25%-75% of the maximum stress, a cycle frequency of 1.2 Hz, and 150,000 cycles. After the test, X-ray tomography is used to detect damage and performance degradation within the interface.

[0052] Performance optimization: If the test results do not meet the standards, the material microstructure and composition will be tested using analytical tools such as atomic force microscopy and Raman spectrometer. Based on the performance test data, the composition ratio and microstructure processing parameters of the transition layer material will be adjusted, or the hot pressing temperature, pressure, time, ultrasonic and magnetic field parameters will be optimized. The material will then be re-prepared and re-tested until the performance requirements are met. Example

[0053] Please see the attached Figure 1 -Attached Figure 4 , the glass-ceramic with a thickness of 3 mm was selected, the main crystal phase of which is wollastonite and diopside, with a density of 2.6 g / cm³, an elastic modulus of 85 GPa, and a thermal expansion coefficient of 8×10 -6 / K, using a high-precision laser cutting machine to cut the microcrystalline glass. The laser wavelength of the laser cutting machine is 1064nm, the pulse frequency range is 0kHz-500kHz, the maximum pulse energy can reach 100mJ, and the cutting accuracy can reach ±0.01mm. The microcrystalline glass can be cut into 500mm×500mm square plates. Subsequently, the glass surface is polished using magnetorheological polishing technology to control the surface roughness to Ra0.02μm. Then, a CNC edge grinder is used to perform a 45° chamfer on the glass edge, and the chamfer width is set to 0.3mm. Finally, the processed microcrystalline glass is transferred to a plasma cleaning machine with a power set to 150W and a cleaning process for 5 minutes to obtain a microcrystalline glass layer;

[0054] Intermediate layer material: The intermediate layer material adopts a three-layer composite structure. From the outside to the inside, it is composed of 0.2mm thick ethylene-vinyl acetate copolymer, 0.36mm thick polydimethylsiloxane, and 0.2mm thick thermoplastic polyurethane. In a clean environment with a temperature of 22°C and a humidity of 25%, a precision cutting machine is used to cut the composite intermediate layer into a size of 510mm×510mm. After cutting, it is transferred to a vacuum drying oven and dried at a temperature of 35°C for 6 hours to obtain the composite intermediate layer.

[0055] Preparation of transition layer materials,

[0056] The first transition layer: polyetheretherketone is used as the matrix, and a variety of materials are added, among which the mass fraction of nano-titanium dioxide particles is 8%, and the particle size is 15nm, the mass fraction of graphene nanosheets is 0.3%, and the lateral size is 1μm-3μm, the mass fraction of shape memory alloy microfilaments is 2%, the microfilament diameter is 50μm, and the length is 0.5mm-1mm, the mass fraction of ultra-high molecular weight polyethylene fibers is 1%, and the fiber length is 5mm-10mm. A twin-screw extruder is used for blending, and the extrusion temperature is set to 380℃ and the screw speed is 80r / min. After blending, a hot pressing process is used to press the film into a thickness of 0.12mm at a temperature of 360℃ and a pressure of 5MPa. The film size is 505mm×505mm. After molding, it is placed in a clean environment at 25℃ for annealing. The annealing temperature is set to 180℃ and kept warm for 2h to obtain the first transition layer.

[0057] The second transition layer: In terms of material composition, the content of nano-titanium dioxide particles is increased to 12%, the content of graphene nanosheets is increased to 0.5%, the content of shape memory alloy microfilaments is reduced to 3%, the content of carbon nanofibers is 1%, and their diameter is 10nm-20nm, and the length is 5μm-10μm. The content of ultra-high molecular weight polyethylene fibers is increased to 1.5%. At the same time, aerogel particles are evenly dispersed in the material. The aerogel particles have a particle size of 50nm-100nm and a volume fraction of 5%. The rest of the preparation process is the same as the first transition layer, and a 0.16mm thick film is made;

[0058] The third transition layer: The content of nano-titanium dioxide particles in this layer is 16%, the content of graphene nanosheets is 0.8%, the content of shape memory alloy microfilaments is 4%, the content of carbon nanofibers is 2%, the content of ultra-high molecular weight polyethylene fibers is 2%, and the volume fraction of aerogel particles is increased to 8%, making a 0.22mm thick film;

[0059] The fourth transition layer: This layer contains 20% nano-titanium dioxide particles, 1% graphene nanosheets, 5% shape memory alloy microfilaments, 3% carbon nanofibers, 2.5% ultra-high molecular weight polyethylene fibers, and 10% aerogel particles by volume. It is made into a 0.28mm thick film. After each transition layer film is prepared, it is left to stand in an environment with a temperature of 23°C and a humidity of 20% for 48 hours to fully stabilize the material properties.

[0060] Polymer gradient interlayer: A polymer gradient interlayer was prepared using polymethyl methacrylate as the matrix and doped with nano-silica particles. The polymethyl methacrylate was first dried at 82°C for 4 hours, then transferred to a high-speed blender with the nano-silica particles and stirred at 1100 r / min for 30 minutes. After stirring, the mixture was placed in a hot pressing mold and hot pressed at 160°C and 5 MPa for 18 minutes to form an organic polymer gradient interlayer with a thickness of 0.4 mm. The concentration of nano-silica particles near the glass layer in the interlayer was 2%, and the concentration near the middle layer was 8%.

[0061] The layers are stacked in the order of glass-ceramic layer - first transition layer - organic polymer gradient interlayer - second transition layer - organic polymer gradient interlayer - third transition layer - organic polymer gradient interlayer - fourth transition layer - composite intermediate layer - fourth transition layer - organic polymer gradient interlayer - third transition layer - organic polymer gradient interlayer - second transition layer - organic polymer gradient interlayer - first transition layer - glass-ceramic layer. A high-precision positioning platform is used to ensure that the centers of each layer are strictly aligned, and the interlayer misalignment error is controlled within ±0.05mm. A femtosecond laser processing system is used for surface processing. The system has an output laser wavelength of 800nm, a pulse width of 35fs, and a repetition frequency of 1k Between Hz and 1MHz, a groove structure with a depth of 80nm and a spacing of 250nm is machined on the surface of the first transition layer, a column structure with a diameter of 1.5μm and a height of 4μm is machined on the second transition layer, a porous structure with a pore size of 350nm and a porosity of 12% is machined on the third transition layer, and a composite gradient structure is machined on the fourth transition layer. The characteristics of shape memory alloy microwires are used to give the transition layer a temperature-related functional gradient. The phase transition temperature of the shape memory alloy microwires in the transition layer close to the microcrystalline glass layer is set to 65℃, and as it transitions to the middle layer, the phase transition temperature gradually decreases to 45℃, realizing the gradient stress adjustment function under different temperature environments;

[0062] Pre-strain treatment: Fix the transition layer material on the stretching device and perform pre-stretching treatment at a speed of 0.5mm / min. The pre-stretching strain of the first transition layer is controlled at 5%, the second transition layer is 6%, the third transition layer is 7%, and the fourth transition layer is 8%. Maintain the pre-stretching for 10 minutes and slowly release the stress after completion.

[0063] Pre-pressing treatment: Place the pre-strained material in a vacuum hot pressing machine and pre-press for 12 minutes at a temperature of 75°C and a pressure of 0.6 MPa. During the pre-pressing process, maintain a vacuum degree of -0.095 MPa to fully remove the air between the layers.

[0064] Hot pressing bonding: The temperature was raised to 155°C at a rate of 1.5°C / min, and the pressure was increased to 4.5MPa. Ultrasonic waves with a frequency of 25kHz and a power of 600W, as well as a pulsed magnetic field with an intensity of 0.5T, were applied simultaneously. The pulse frequency was set to 10Hz, and the pressure and magnetism were maintained for 13 minutes to promote the fusion of the materials and improve their performance.

[0065] Cooling and demoulding: After hot pressing is completed, the temperature is lowered to 60℃ at a rate of 1℃ / min. After cooling is completed, the pressure is slowly released and demoulding is carried out, and the demoulding force is controlled at 60N to finally produce the aviation glass product.

[0066] Comparative Example 1

[0067] Glass layer material: ordinary float glass with a thickness of 3mm, a density of 2.45g / cm³, an elastic modulus of 68GPa, and a thermal expansion coefficient of 9.5×10 -6 / K;

[0068] Middle layer material: 0.5mm thick polyvinyl butyral;

[0069] Transition layer material: a transition layer is set up with epoxy resin as the matrix and 10% mass fraction of ordinary silica particles with a particle size of 50nm;

[0070] First, ordinary float glass was cut into 500mm×500mm square plates, and the surface was simply polished using ordinary grinding equipment to a surface roughness of about Ra0.3μm. The edges were conventionally rounded with a fillet radius of about 1mm.

[0071] Cut the PVB interlayer material into 510mm×510mm size at 20℃-25℃;

[0072] Epoxy resin and silica particles were mixed in a low-speed mixer at 600 rpm for 20 minutes, then poured into a mold and cured at 80°C and 2 MPa for 2 hours to form a 0.15 mm thick transition layer film.

[0073] The stacking process is carried out in the order of glass layer - transition layer - middle layer - transition layer - glass layer. The stacking process relies on manual operation to control the misalignment error within ±0.3mm.

[0074] The stacked materials were placed in a common laminator and laminated at a temperature of 130°C and a pressure of 1.2 MPa for 40 minutes. After lamination, the materials were naturally cooled to room temperature and demoulded to obtain aviation glass.

[0075] Comparative Example 2

[0076] Glass layer material: Quartz glass with a thickness of 3 mm, a density of 2.2 g / cm³, an elastic modulus of 73 GPa, and a thermal expansion coefficient of 5.5×10 -7 / K;

[0077] Middle layer material: new type of 0.4mm thick thermosetting polyurethane elastomer;

[0078] Transition layer material: Set up three transition layers, each layer is based on polycarbonate, the first layer is added with 5% by mass of nano-alumina particles, the second layer is added with 8% by mass of nano-alumina particles, and the third layer is added with 10% by mass of nano-alumina particles;

[0079] Quartz glass was cut into 500 mm × 500 mm square plates using a CNC cutting machine, and then chemically polished to a surface roughness of Ra 0.1 μm. The edges were chamfered at 45° with a chamfer width of 0.2 mm.

[0080] The thermosetting polyurethane elastomer was cut into a size of 510 mm × 510 mm in an environment with a temperature of 23°C and a humidity of 20%;

[0081] Polycarbonate and nano-alumina particles in different proportions were mixed in a high-speed mixer at 1500 rpm for 30 minutes. Transition layer sheets with thicknesses of 0.1 mm, 0.12 mm, and 0.15 mm were then produced through injection molding at a temperature of 280°C and a pressure of 8 MPa.

[0082] The layers are stacked in the order of glass layer - first transition layer - middle layer - second transition layer - third transition layer - glass layer. Positioning is performed using a positioning fixture. The inter-layer misalignment error is controlled within ±0.2mm.

[0083] The stacked materials were placed in a vacuum hot pressing device and hot pressed for 30 minutes at a temperature of 160°C and a pressure of 2.5 MPa. The vacuum degree was maintained at -0.09 MPa during the hot pressing process. After the hot pressing was completed, the material was cooled to room temperature at a rate of 5°C / min and demolded to produce aviation glass.

[0084] The examples and two comparative examples were tested, including a thermal cycle test, a bird strike simulation test, a chemical corrosion resistance test, and a dynamic mechanical analysis test. The specific test procedures are as follows:

[0085] 1. Thermal cycle test,

[0086] Simulate the large temperature changes that glass undergoes during aviation flight to test the structural stability and performance retention of aviation glass under thermal stress and verify its thermal shock resistance.

[0087] The aviation glass samples were placed in a high-low temperature alternating test chamber with a set temperature range of -50°C to 80°C. The temperature was raised from room temperature to 80°C at a rate of 5°C / min and held for 2 hours. The temperature was then lowered to -50°C at the same rate and held for 2 hours. This constituted one cycle. After 20 cycles were repeated, the glass surface was observed for cracks and delamination between layers. An optical interferometer was used to measure changes in surface flatness, and changes in light transmittance and tensile strength were tested.

[0088] 2. Bird strike simulation test

[0089] Simulate the extreme situation of a bird strike during flight to evaluate the ability of aviation glass to withstand high-speed impact and verify its safety in actual dangerous scenarios;

[0090] Using a gas cannon launcher, a 1.8kg chicken-shaped projectile (simulating a bird) was fired at the center of an aviation glass sample at a speed of 250km / h. A high-speed camera was used to record the deformation, crack initiation, and growth of the glass at the moment of impact. After the impact, the glass was inspected for penetration, the crack extension range was measured, and the remaining strength of the glass was tested. The performance data was then compared with that before the impact to analyze its bird strike resistance.

[0091] 3. Chemical corrosion resistance test,

[0092] Test the ability of aviation glass to withstand the erosion of common chemicals, evaluate its chemical stability in different environments, and ensure that the performance of the glass is not affected by chemicals;

[0093] Prepare three common chemical solutions: 5% sulfuric acid solution, 5% sodium hydroxide solution, and 10% sodium chloride solution. Immerse aviation glass samples in each of these solutions at a temperature of 25°C for 48 hours. After immersion, remove the samples, rinse with clean water, and dry them. Observe the glass surface for discoloration, corrosion pits, and other phenomena. Use a scanning electron microscope to observe changes in the surface microstructure, test changes in transmittance and hardness, and evaluate the glass's chemical corrosion resistance.

[0094] 4. Dynamic mechanical analysis test

[0095] Study the dynamic mechanical properties of aviation glass at different frequencies and temperatures, understand the viscoelastic properties of the material, analyze its energy absorption and loss under dynamic loads, and further verify the rationality of material design;

[0096] Using a dynamic mechanical analyzer, aviation glass samples were cut into specimens with a size of 50mm×10mm×3mm. Under a nitrogen protective atmosphere, the temperature range was set from -100℃ to 150℃, the heating rate was 3℃ / min, and the test frequency range was 0.1Hz to 100Hz. The storage modulus, loss modulus and damping factor of the specimens at different temperatures and frequencies were measured to analyze the dynamic mechanical behavior of the material and evaluate its performance in complex dynamic environments.

[0097] Example test results:

[0098] (1) Thermal cycle test,

[0099] Procedure: Place the aviation glass sample of the embodiment in a high-low temperature alternating test chamber, raise the temperature from 25°C to 80°C at a rate of 5°C / min, hold for 2 hours, then cool to -50°C at the same rate and hold for 2 hours to complete one cycle. Repeat this process 20 times. After the cycle is complete, measure the surface flatness with an optical interferometer, and test the light transmittance and tensile strength using a light transmittance tester and an electronic universal material testing machine, respectively.

[0100] Data: There are no cracks on the glass surface, no delamination between layers, and minimal change in surface flatness. The transmittance has dropped from the initial 92% to 91.5%, and the tensile strength has dropped from 28MPa to 27.8MPa.

[0101] (2) Bird strike simulation test,

[0102] Operation: A 1.8kg chicken-shaped bird shot was mounted on a gas cannon launcher and fired at a speed of 250km / h to impact the center of the aviation glass sample. The entire process was recorded with a high-speed camera. After the impact, the glass penetration was checked, the crack extension range was measured, and the residual strength was tested.

[0103] Data: The glass was not penetrated, the maximum crack extension range was 40mm, and the residual tensile strength was 24MPa, a decrease of about 14.3% compared to before the impact;

[0104] (3) Chemical corrosion resistance test,

[0105] Procedure: Prepare 500 mL each of 5% sulfuric acid solution, 5% sodium hydroxide solution, and 10% sodium chloride solution, and immerse the aviation glass sample in each of them at 25°C for 48 hours. After immersion, rinse with water and dry. Observe the surface with a scanning electron microscope and test the transmittance and hardness.

[0106] Data: After immersion in the three solutions, no discoloration or corrosion pits appeared on the glass surface. After immersion in sulfuric acid solution, the transmittance was 91% and the hardness did not change significantly. After immersion in sodium hydroxide solution, the transmittance was 91.2% and the hardness decreased slightly by 0.5H. After immersion in sodium chloride solution, the transmittance was 91.3% and the hardness decreased by 0.3H.

[0107] (IV) Dynamic mechanical analysis test

[0108] Procedure: Cut the aviation glass from the example into 50 mm × 10 mm × 3 mm specimens and place them in a dynamic mechanical analyzer. Under nitrogen protection, heat the sample from -100°C to 150°C at a rate of 3°C / min. Test the sample at a frequency ranging from 0.1 Hz to 100 Hz, and record the storage modulus, loss modulus, and damping factor data.

[0109] Data: At -100°C and 0.1Hz, the storage modulus is 12GPa, at room temperature 25°C and 10Hz, the storage modulus is 8GPa, the loss modulus is 0.8GPa, the damping factor is 0.1, and at 150°C and 100Hz, the storage modulus is 3GPa.

[0110] Comparative Example 1 Test Results:

[0111] (1) Thermal cycle test,

[0112] Operation: Same as in Example 1, the aviation glass sample of Comparative Example 1 was subjected to 20 thermal cycles from -50°C to 80°C, and then various performance tests were performed;

[0113] Data: There are no abnormalities on the glass surface and between layers, the surface flatness remains good, the transmittance decreases from 92.2% to 91.8%, and the tensile strength decreases from 28.2MPa to 28MPa;

[0114] (2) Bird strike simulation test,

[0115] Operation: The same bird strike simulation operation process as in Example 1 was used to test the aviation glass sample of Comparative Example 1;

[0116] Data: The glass was not penetrated, the maximum crack extension length was 38mm, and the residual tensile strength was 24.5MPa, which was about 13.1% lower than before the impact;

[0117] (3) Chemical corrosion resistance test,

[0118] Operation: Immerse the aviation glass sample of Comparative Example 1 in three chemical solutions respectively, under the same conditions as in the embodiment, and observe and test after immersion;

[0119] Data: After immersion in the three solutions, there is no obvious corrosion on the glass surface. After immersion in sulfuric acid solution, the transmittance is 91.3% and the hardness has no significant change. After immersion in sodium hydroxide solution, the transmittance is 91.5% and the hardness decreases by 0.4H. After immersion in sodium chloride solution, the transmittance is 91.4% and the hardness decreases by 0.2H.

[0120] (4) Dynamic mechanical analysis test,

[0121] Operation: Prepare the sample of comparative example 1 and put it into the dynamic mechanical analyzer, and test it according to the set conditions;

[0122] Data: At -100℃ and 0.1Hz, the storage modulus is 11.8GPa, at 25℃ and 10Hz, the storage modulus is 7.9GPa, the loss modulus is 0.78GPa, the damping factor is 0.11, and at 150℃ and 100Hz, the storage modulus is 2.9GPa.

[0123] Comparative Example 2 Test Results:

[0124] (1) Thermal cycle test,

[0125] Operation: Perform 20 thermal cycles on the aviation glass sample of Comparative Example 2, using the same operating steps as in Example 1, and test the performance after the cycles;

[0126] Data: The glass has no cracks or delamination, the surface flatness is stable, the transmittance is reduced from 91.8% to 91.3%, and the tensile strength is reduced from 27.8MPa to 27.5MPa;

[0127] (2) Bird strike simulation test,

[0128] Operation: Referring to the bird strike test method in the embodiment, an impact test was performed on the aviation glass sample of comparative example 2;

[0129] Data: The glass was not penetrated, the maximum crack extension was 39mm, and the residual tensile strength was 24.2MPa, a decrease of about 13.6% compared to before the impact;

[0130] (3) Chemical corrosion resistance test,

[0131] Operation: Immerse the aviation glass sample of Comparative Example 2 in three chemical solutions under the same operating conditions as in Example 1, and perform performance testing after immersion;

[0132] Data: After soaking in the three solutions, the glass surface is in good condition. After soaking in sulfuric acid solution, the transmittance is 91.1%, and the hardness has no obvious change. After soaking in sodium hydroxide solution, the transmittance is 91.2%, and the hardness decreases by 0.4H. After soaking in sodium chloride solution, the transmittance is 91.3%, and the hardness decreases by 0.3H.

[0133] (4) Dynamic mechanical analysis test,

[0134] Operation: Place the sample of comparative example 2 in a dynamic mechanical analyzer and test it within the set temperature and frequency range;

[0135] Data: At -100℃ and 0.1Hz, the storage modulus is 12.2GPa, at 25℃ and 10Hz, the storage modulus is 8.1GPa, the loss modulus is 0.82GPa, the damping factor is 0.1, and at 150℃ and 100Hz, the storage modulus is 3.1GPa.

[0136] The test data of the above embodiments and two groups of comparative examples show that the aviation glass of the present invention performs stably and excellently in various performance tests, further verifying the reliability and practicality of the design method.

[0137] Although the present invention is disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent variations, and modifications made to the above embodiments in accordance with the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for designing an interface enhancement gradient for an impact-resistant aviation glass laminate structure, comprising glass material preparation, interface enhancement gradient design, lamination, quality inspection, and performance testing, characterized in that: The glass material includes a glass layer material, an intermediate layer material, and a transition layer material. The lamination process includes pre-strain treatment, pre-pressing treatment, hot pressing bonding, and cooling demoulding. The interface enhancement gradient design method of the aviation glass laminate structure has the following specific operating steps: Step 1: Select microcrystalline glass as the glass layer material for cutting and cleaning for standby use; the intermediate layer material is made of a mixture of ethylene-vinyl acetate copolymer, polydimethylsiloxane and thermoplastic polyurethane; the first layer of the transition layer material is based on polyetheretherketone, and nano-titanium dioxide particles, graphene nanosheets, shape memory alloy microfilaments and ultra-high molecular weight polyethylene fibers are added; the content of nano-titanium dioxide particles, graphene nanosheets, shape memory alloy microfilaments and ultra-high molecular weight polyethylene fibers in each transition layer gradually increases; the transition layer material includes a first transition layer, a second transition layer, a third transition layer, a fourth transition layer and a polymer gradient interlayer; Step 2: Assemble and stack the glass layer material, the intermediate layer material, and the transition layer material in order; Step 3: Pre-strain the transition layer material before lamination, pre-press to remove air between layers after the treatment, and cool and demould after hot pressing to obtain the finished aviation glass product; Step 4: Conduct quality inspection on the finished aviation glass products, including appearance inspection and mechanical property testing. The mechanical property testing includes tensile testing, drop hammer impact testing and fatigue testing.

2. The interface reinforcement gradient design method for an impact-resistant aviation glass laminate structure according to claim 1, characterized in that: The contents of nano-titanium dioxide particles in the second transition layer, the third transition layer and the fourth transition layer are 12%, 16% and 20% respectively, the contents of graphene nanosheets are 0.5%, 0.8% and 1% respectively, the contents of shape memory alloy microfilaments are 3%, 4% and 5% respectively, the contents of carbon nanofibers are 1%, 2% and 3% respectively, and the contents of ultra-high molecular weight polyethylene fibers are 1.5%, 2% and 2.5% respectively.

3. The method for designing an interface reinforcement gradient for an impact-resistant aviation glass laminate structure according to claim 2, wherein: The polymer gradient interlayer is based on polymethyl methacrylate and doped with nano-silica particles. The specific preparation steps are as follows: The polymethyl methacrylate was dried at a temperature of 80°C-85°C for 4 hours, and then transferred into a high-speed mixer with nano-silica particles and stirred at a speed of 1000r / min-1200r / min for 30 minutes. After the stirring was completed, the mixture was placed in a hot pressing mold and hot pressed at a temperature of 160°C and a pressure of 5MPa for 15min-20min to form an organic polymer gradient interlayer with a thickness of 0.4mm.

4. The method for designing an interface reinforcement gradient for an impact-resistant aviation glass laminate structure according to claim 3, wherein: In the step one, a microcrystalline glass with a thickness of 3 mm is selected, and a high-precision laser cutting machine is used to cut the microcrystalline glass into 500 mm × 500 mm square plates, and the glass surface is polished using magnetorheological polishing technology. The surface roughness is controlled at Ra0.02 μm, and the glass edge is chamfered at 45° using a CNC grinding machine with a chamfer width of 0.3 mm. After the treatment is completed, it is transferred to a plasma cleaning machine with a power set to 150 W. After cleaning for 5 minutes to 10 minutes, a microcrystalline glass layer is obtained, which is the glass layer material.

5. The method for designing an interface reinforcement gradient for an impact-resistant aviation glass laminate structure according to claim 4, wherein: In the step 1, the three layers of composite material are ethylene-vinyl acetate copolymer, polydimethylsiloxane and thermoplastic polyurethane from the outside to the inside, respectively. The three layers of material represent the outer layer, the middle layer and the inner layer, respectively. The thicknesses of the three layers of material are 0.2 mm, 0.36 mm and 0.2 mm, respectively. In a clean environment with a temperature of 22°C and a humidity of 25%, a precision cutting machine is used to cut the composite middle layer into a size of 510 mm × 510 mm. After completion, it is transferred to a vacuum drying oven and dried at a temperature of 35°C for 6 hours to obtain a composite middle layer, which is the middle layer material.

6. The method for designing an interface reinforcement gradient for an impact-resistant aviation glass laminate structure according to claim 5, wherein: In the step 1, the first transition layer is based on polyetheretherketone, and is added with 8% by mass of nano-titanium dioxide particles, 0.3% by mass of graphene nanosheets, 2% by mass of shape memory alloy microfilaments, and 1% by mass of ultra-high molecular weight polyethylene fibers. The mixture is blended using a twin-screw extruder, the extrusion temperature is set to 380°C, the screw speed is 80r / min-100r / min, and a hot pressing molding process is used to press the film into a 0.12mm-0.13mm thick film at a temperature of 360°C-380°C and a pressure of 5MPa. The film has a size of 505mm×505mm. After molding, the film is placed in a clean environment at 25°C for annealing at an annealing temperature of 180°C and kept warm for 2h-3h to obtain the first transition layer.

7. The method for designing an interface reinforcement gradient for an impact-resistant aviation glass laminate structure according to claim 6, wherein: In the step 2, the layers are stacked in the order of microcrystalline glass layer-first transition layer-organic polymer gradient interlayer-second transition layer-organic polymer gradient interlayer-third transition layer-organic polymer gradient interlayer-fourth transition layer-composite intermediate layer-fourth transition layer-organic polymer gradient interlayer-third transition layer-organic polymer gradient interlayer-second transition layer-organic polymer gradient interlayer-first transition layer-microcrystalline glass layer, and the interlayer misalignment error is controlled between ±0.05mm. Femtosecond laser processing technology is used to process a groove structure with a depth of 50nm-100nm and a spacing of 200nm-300nm on the surface of the first transition layer, a columnar structure with a diameter of 1μm-2μm and a height of 3μm-5μm is processed in the second transition layer, a porous structure with a pore diameter of 200nm-500nm and a porosity of 10%-15% is processed in the third transition layer, and a composite gradient structure is processed in the fourth transition layer.

8. The method for designing an interface reinforcement gradient for an impact-resistant aviation glass laminate structure according to claim 7, wherein: In the step three, the transition layer material is fixed on the stretching device and pre-stretched at a speed of 0.5 mm / min. The pre-stretching strain of the first transition layer is controlled at 5%, the second transition layer is 6%, the third transition layer is 7%, and the fourth transition layer is 8%. After pre-stretching, it is maintained for 10 minutes, and the stress is slowly released after completion.

9. The method for designing an interface reinforcement gradient for an impact-resistant aviation glass laminate structure according to claim 8, wherein: In the step three, the pre-strained material is placed in a vacuum hot pressing molding machine, pre-pressed for 12 minutes to 15 minutes at a temperature of 75°C and a pressure of 0.6 MPa, and the vacuum degree is maintained at -0.095 MPa during the pre-pressing process. The hot pressing is combined with heating to 155°C at a rate of 1.5°C / min, and the pressure is increased to 4.5 MPa. At the same time, ultrasonic waves with a frequency of 25kHz and a power of 600W and a pulsed magnetic field with an intensity of 0.5T are applied, the pulse frequency is 10Hz, and the pressure and magnetism are maintained for 13 minutes to 15 minutes. After the hot pressing is completed, the temperature is lowered to 60°C at a rate of 1°C / min. After the cooling is completed, the pressure is slowly released and the mold is demolded, and the demolding force is controlled to be 50N-80N to obtain an aviation glass product.

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