Carbon fiber reinforced metal laminate and preparation method of bionic micro-nano structure of carbon fiber reinforced metal laminate

Abstract

The invention discloses a carbon fiber reinforced metal laminate and a preparation method of a bionic micro-nano structure of the carbon fiber reinforced metal laminate. The carbon fiber reinforced metal laminate comprises an upper metal layer, a lower metal layer and a carbon fiber layer arranged between the upper metal layer and the lower metal layer, and bionic micro-nano structures are arranged on the surfaces of the upper metal layer and the lower metal layer. The preparation method comprises the steps of metal matrix pretreatment, micro-nano structure preparation, laminate assembly and the like. The bionic micro-nano structure is prepared on the surface of the metal matrix, so that the interface bonding strength between the metal matrix and the carbon fiber layer is effectively improved, the defect that the cured laminate metal matrix and the fiber reinforced prepreg are easy to layer is overcome, and the overall performance of the carbon fiber reinforced metal laminate is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal preparation, and in particular relates to a carbon fiber reinforced metal laminate and a method for preparing a bionic micro-nano structure thereof. Background Art

[0002] Fiber reinforced metal laminate (FRM) is a new type of structural material. It is made by bonding two or more metal sheets with reinforcing fibers sandwiched between the sheets using adhesive. It has good fatigue and damage resistance, excellent environmental and lightning resistance, and good damping and formability. It is widely used in aerospace, magnetic trains, lightweight bulletproof armor, automobiles, ships, pipelines and other fields.

[0003] In traditional fiber-reinforced metal laminates, delamination between the metal matrix and the fiber-reinforced prepreg is common after curing. This is primarily due to the inability of conventional metal surface treatments to provide sufficient interfacial bonding strength. For example, while mechanical methods such as sandblasting and shot peening, chemical or electrochemical treatments such as acid or alkaline etching and anodizing, and grafting of coupling agents onto metal surfaces can improve interfacial bonding strength to a certain extent, they still have limitations. Summary of the Invention

[0004] To solve the above problems, the present invention provides a carbon fiber reinforced metal laminate, comprising: An upper metal layer, a lower metal layer, and a carbon fiber layer arranged between the upper metal layer and the lower metal layer, wherein the surfaces of the upper metal layer and the lower metal layer are provided with a bionic micro-nano structure, wherein the bionic micro-nano structure is composed of a micron-scale main hole that is at a certain angle to the surface of the metal substrate and forms a mechanical locking structure with the metal substrate, and a micro-nano composite structure composed of nanometer-scale secondary holes connected to the main hole, or a nanometer-scale spatial inclined dense hole structure that is at a certain tilt angle to the surface of the metal substrate, or a nanometer-scale spatial network dense hole structure.

[0005] Preferably, the material of the upper metal layer and the lower metal layer is at least one of aluminum alloy, titanium alloy, aluminum-copper alloy, aluminum-zinc alloy, titanium alloy or steel.

[0006] Preferably, the carbon fiber layer is in the form of at least one of unidirectionally arranged non-woven fabric, woven fabric, or chopped fibers.

[0007] Preferably, the method for preparing a biomimetic micro-nanostructure comprises the following steps: S1. Metal substrate pretreatment: Clean the metal substrates used for the upper and lower metal layers to remove impurities such as oil, oxide layers, etc. S2. Micro-nanostructure preparation: The biomimetic micro-nanostructure of claim 1 is prepared on the surface of a metal substrate using at least one of photolithography, electron beam lithography, and nanoprinting. In the photolithography process, parameters such as exposure time and development time must be optimized based on the type of photoresist and the target micro-nanostructure size. S3. Laminate Assembly: The prepared biomimetic micro-nanostructure upper metal layer, carbon fiber layer, and lower metal layer are stacked in sequence and bonded together using a hot pressing process to form a carbon fiber reinforced metal laminate. Parameters such as hot pressing temperature, pressure, and time are selected based on the material properties of the metal matrix and carbon fiber layers.

[0008] The beneficial effects of the present invention are: The presence of the bionic micro-nanostructure increases the contact area and mechanical locking effect between the metal matrix and the carbon fiber layer, effectively improving the interface bonding strength and solving the defect of easy delamination of traditional metal surface treatment methods; Due to the improvement of interface performance, the mechanical properties of carbon fiber reinforced metal laminates, such as bending strength and shear strength, have been significantly improved, which can better meet the high performance requirements of materials in fields such as aerospace. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the specific embodiments of the invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0010] Figure 1 Schematic diagram of the structure of the carbon fiber reinforced metal laminate of the present invention.

[0011] In the picture: Upper metal layer 1, lower metal layer 2, carbon fiber layer 3. DETAILED DESCRIPTION

[0012] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0013] Metal substrate pretreatment: Material Selection: Both the upper and lower metal layers are made of 7075-T6 aluminum alloy, with a thickness of 0.5 mm and a surface roughness of Ra ≤ 0.4 μm. Pretreatment: Surface cleaning: An ultrasonic cleaner with acetone as the solvent is used for 15 minutes to remove oil and impurities from the metal substrate surface. Chemical etching: Etching in a 5wt% NaOH solution at 50°C for 5 minutes removes the oxide layer, exposing the fresh metal surface.

[0014] 2. Preparation of biomimetic micro-nanostructures Structure Type: A micro-nano composite structure consisting of micron-scale inner and outer "eight"-shaped main holes connected to the main holes by nanoscale secondary holes inspired by the barbed structure of arthropod legs. Fabrication Process: Photolithography: Using positive photoresist (AZ4620), spin-coating to a thickness of 3μm, with a pre-bake temperature of 90°C for 2 minutes; exposure time optimized to 15 seconds based on the lithography machine model and light source intensity, and a development time of 40 seconds to produce the main hole pattern. Electron beam lithography: Based on the main hole, nanoscale secondary holes were formed using electron beam lithography at an accelerating voltage of 30kV, a beam current of 1nA, and an exposure dose of 200μC / cm². Etching: Reactive ion etching (RIE) was used with a CF4 / O2 mixture (volume ratio of 4:1) for 10 minutes to form the micro-nano composite structure with a depth of 2μm.

[0015] 3. Carbon Fiber Layer Preparation Material selection: T700 grade carbon fiber unidirectional non-woven fabric with a surface density of 200g / m² and a thickness of 0.2mm.

[0016] Pretreatment: The carbon fiber cloth is dried at 120°C for 2 hours to remove moisture and improve the bonding strength with the metal matrix.

[0017] 4. Shelf assembly The stacking order is: upper metal layer (bionic micro-nanostructure facing down), carbon fiber layer, lower metal layer (bionic micro-nanostructure facing up). Hot pressing process: temperature: 180°C; pressure: 8MPa; time: 60 minutes to ensure a tight bond between the layers.

[0018] 5. Performance Verification Interlaminar shear strength: ≥70MPa, 20% higher than traditional laminates; fatigue life: ≥2×10 5 times of cycles, meeting the use requirements in the aerospace field.

[0019] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A carbon fiber reinforced metal laminate, characterized in that: include: An upper metal layer (1), a lower metal layer (2), and a carbon fiber layer (3) arranged between the upper metal layer (1) and the lower metal layer (2); surfaces of the upper metal layer (1) and the lower metal layer (2) are provided with a bionic micro-nano structure, the bionic micro-nano structure being composed of a micron-scale main hole that is at a certain angle to the metal substrate surface and forms a mechanical locking structure with the metal substrate, and a micro-nano composite structure composed of nanometer-scale secondary holes connected to the main hole, or a nanometer-scale spatial inclined dense hole structure that is at a certain tilt angle to the metal substrate surface, or a nanometer-scale spatial mesh-like dense hole structure.

2. The carbon fiber reinforced metal laminate according to claim 1, wherein: The material of the upper metal layer (1) and the lower metal layer (2) is at least one of aluminum alloy, titanium alloy, aluminum-copper alloy, aluminum-zinc alloy, titanium alloy or steel.

3. The carbon fiber reinforced metal laminate according to claim 1, wherein: The carbon fiber layer (3) is in the form of at least one of unidirectionally arranged non-woven fabric, woven fabric, or chopped fibers.

4. A method for preparing a bionic micro-nano structure of a carbon fiber reinforced metal laminate according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Metal substrate pretreatment: cleaning the surface of the metal substrate used for the upper metal layer (1) and the lower metal layer (2) to remove impurities such as oil, oxide layer, etc.; S2. Micro-nanostructure preparation: The biomimetic micro-nanostructure of claim 1 is prepared on the surface of a metal substrate using at least one of photolithography, electron beam lithography, and nanoprinting. In the photolithography process, parameters such as exposure time and development time must be optimized based on the type of photoresist and the target micro-nanostructure size. S3. Laminate assembly: The prepared biomimetic micro-nanostructure upper metal layer (1), carbon fiber layer (3), and lower metal layer (2) are stacked in sequence, and the layers are tightly bonded together through a hot pressing process to form a carbon fiber reinforced metal laminate. Parameters such as hot pressing temperature, pressure, and time are selected based on the material properties of the metal matrix and the carbon fiber layer (3).

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