Pitch-based carbon fiber reflector seat and manufacturing method thereof

Abstract

The invention relates to the technical field of optical elements, and discloses an asphalt-based carbon fiber reflector seat, which comprises an upper box body and a lower box body, and is characterized in that each box body is formed by splicing a plurality of carbon fiber splice plates; the carbon fiber splice plate is formed by cutting a rectangular pitch-based carbon fiber plate; the pitch-based carbon fiber plate is formed by laying and mould pressing pitch-based carbon fiber unidirectional prepreg cloth according to angles of 0 degree, 45 degrees, 90 degrees and 135 degrees, so that the mechanical property of the carbon fiber plate is enhanced through multi-angle laying, the strength and the stability of the reflector seat are improved, and the reliability and the durability of the whole structure are ensured. The pitch-based carbon fiber plate has the thermal expansion coefficient of 0.15 * 10 <-5 > K <-1 > and can meet the requirement of the aerospace field for the thermal expansion coefficient, the low thermal expansion coefficient enables the size change of the reflector base to be small when the temperature changes, the optical performance of the reflector is effectively improved, and therefore the precision and stability of an optical system can be improved; the method is especially suitable for high-precision optical application.

Description

Technical Field

[0001] The present invention relates to the technical field of optical elements, and more specifically, to an asphalt-based carbon fiber reflector seat and a method for manufacturing the asphalt-based carbon fiber reflector seat. Background Art

[0002] The reflector is a component that is of great significance in the field of optics, especially in high-end application scenarios such as space optical remote sensing technology and airborne radar.

[0003] In high-end scientific research equipment, such as some high-precision scientific research instruments, large astronomical telescopes, optical reflector systems in high-energy physics experimental equipment, etc., high precision, temperature, stability and other characteristics are required to ensure the optical performance of the reflector. In these devices, small errors may lead to deviations in experimental results or inaccurate observation data.

[0004] Traditional reflector mounts are mostly made of metal materials, especially titanium alloys, because of their high strength and good corrosion resistance. However, titanium alloys have a high thermal expansion coefficient, which affects the optical performance of the reflector and is also expensive. In recent years, carbon fiber composites have gradually become a new choice for reflector mount materials due to their advantages such as light weight, high strength, and low thermal expansion coefficient.

[0005] Compared with traditional metal materials, the use of carbon fiber reduces the weight of the entire equipment, facilitates the handling, installation and operation of the equipment, has very precise surface flatness and dimensional tolerance, good seismic resistance, extremely low thermal expansion coefficient, corrosion resistance and temperature resistance, which are extremely important in the fields of astronomical observation and aerospace optical detection. It also requires higher strength and rigidity, which can ensure that the reflector mount maintains a stable shape in a complex mechanical environment.

[0006] The invention patent application with publication number CN118849447A discloses a device and method for integrally transferring a PET reflective film to an extra-large carbon plastic spherical reflector, which involves a pre-impregnated epoxy resin carbon fiber reflector seat: the equipment includes a torus flange steel plate, a PMMA substrate, a pre-impregnated epoxy resin carbon fiber reflector seat, a spherical fiberglass plate, a negative pressure pump, an air source, a six-degree-of-freedom robot, a non-contact bubble removal device, and a rotating cup spray gun, wherein a support structure is also used to reinforce the torus flange steel plate and the pre-impregnated epoxy resin carbon fiber reflector seat.

[0007] Although the invention has made significant progress in solving the problem of coating of extra-large reflectors, the material selection and manufacturing method of the reflector base are not described in detail. For example, the thermal expansion coefficient and mechanical properties of the pre-impregnated epoxy resin carbon fiber reflector base in the invention, etc. This scheme aims to manufacture a reflector base with high precision, low thermal expansion coefficient and excellent mechanical properties for the aerospace field.

[0008] In the field of aerospace, the working environment temperature of carbon fiber reflector base is -40℃-80℃. The current requirement is that the thermal expansion coefficient is no more than 2×10 -6 K -1 ; In any thermodynamic application, the thermal conductivity and coefficient of thermal expansion of the material should be carefully considered, especially in applications where these properties affect the ultimate performance and service life. Selecting a material with the appropriate coefficient of thermal expansion can improve efficiency and performance. Summary of the invention

[0009] The present invention aims to overcome at least one defect of the above-mentioned prior art and provides an asphalt-based carbon fiber reflector seat and a method for manufacturing an asphalt-based carbon fiber reflector seat, so as to solve the technical problems in the prior art that the carbon fiber mirror seat has a high thermal expansion coefficient and low mechanical properties.

[0010] The technical solution adopted by the present invention is an asphalt-based carbon fiber reflector seat, which includes: an upper box and a lower box, each box is spliced ​​by a number of carbon fiber splicing plates; the carbon fiber splicing plates are cut from rectangular asphalt-based carbon fiber plates; the asphalt-based carbon fiber plates are molded by asphalt-based carbon fiber unidirectional prepreg cloth at angles of 0°, 45°, 90°, and 135°. This design enhances the mechanical properties of the carbon fiber plates through multi-angle lamination, improves the strength and stability of the reflector seat, and ensures the reliability and durability of the overall structure.

[0011] Preferably, the asphalt-based carbon fiber sheet has a thickness of 0.15×10 -5 K -1 The thermal expansion coefficient is much lower than that of titanium alloy in the prior art, and can meet the requirements of the aerospace field for thermal expansion coefficient. The low thermal expansion coefficient makes the size of the reflector seat change very little when the temperature changes, which effectively improves the optical performance of the reflector, thereby improving the accuracy and stability of the optical system, and is particularly suitable for high-precision optical applications.

[0012] Preferably, the production process of the asphalt-based carbon fiber board includes:

[0013] The asphalt-based carbon fiber cloth was laid at angles of 0°, 45°, 90°, and 135°;

[0014] The molded plate is molded in a molding machine with a temperature of 150°C for 3 hours. The precise layering and molding process ensures the uniformity and consistency of the carbon fiber plate, and improves the mechanical properties and dimensional stability of the material.

[0015] Preferably, the carbon fiber splicing plate is spliced ​​into an upper box body and a lower box body by mortise and tenon technology. During the mortise and tenon connection, resin glue is used for bonding. The mortise and tenon technology combined with resin glue bonding not only improves the strength and reliability of the splicing, but also ensures the overall structural stability and durability of the reflector seat.

[0016] A method for manufacturing the aforementioned asphalt-based carbon fiber reflector seat comprises the following steps:

[0017] S1. Processing the asphalt-based carbon fiber plate in a CNC processing center to process the rectangular carbon fiber plate into a carbon fiber splicing plate that can be connected with mortise and tenon joints;

[0018] S2. Splicing the processed carbon fiber splicing plate into an upper box body and a lower box body through a mortise and tenon process. When the mortise and tenon are connected, resin glue is used for bonding to ensure the reliability of the mortise and tenon connection. After that, the upper box body and the lower box body are bonded with resin glue, and the reflector seat is assembled and formed;

[0019] S3, placing the assembled reflector seat into a curing furnace for heating and curing;

[0020] S4. After curing, the product is taken out and the CNC machining center is used to perform secondary finishing on each panel to achieve high-precision dimensions. Through precise machining and assembly processes, the high precision and high quality of the reflector seat are ensured to meet the requirements of high-precision optical applications.

[0021] As a preferred embodiment, the curing temperature is 150° C. and the curing time is 2 hours. Reasonable curing conditions ensure that the resin glue is fully cured, and improve the overall structural stability and durability of the reflector seat.

[0022] Preferably, the asphalt-based carbon fiber is a mesophase asphalt-based carbon fiber, which has high strength and modulus and good processability.

[0023] Preferably, the bonding strength of the resin glue is not less than 10 MPa. The resin glue with high bonding strength ensures the firmness and reliability of the splicing parts, extends the service life of the reflector seat, and ensures the overall structural stability and durability of the reflector seat.

[0024] Preferably, the precision error of the secondary finishing does not exceed ±0.01 mm. The high-precision secondary finishing ensures the dimensional accuracy of the reflector seat and meets the requirements of high-precision optical applications.

[0025] Preferably, the tensile strength of the mesophase pitch-based carbon fiber is not less than 3 GPa, and the tensile modulus is not less than 250 GPa. The high tensile strength and modulus of the mesophase pitch-based carbon fiber further improve the mechanical properties of the reflector base, ensuring its stability and reliability in a high stress environment.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The invention enhances the mechanical properties of the carbon fiber plate through multi-angle plying, improves the strength and stability of the reflector seat, and ensures the reliability and durability of the overall structure; its thermal expansion coefficient is 0.15×10 -5 K -1 At the same time, the ancient Chinese mortise and tenon structure is innovatively used for connection, which ensures the thermal expansion coefficient requirements of the optical components, improves their service life, ensures their strength, and reduces internal defects caused by manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the reflector base of the present invention.

[0029] Figure 2 It is an angle schematic diagram of the asphalt-based carbon fiber unidirectional prepreg layer of the present invention.

[0030] Figure 3 This is a characteristic diagram of pitch-based carbon fiber.

[0031] In the figure: 1, upper box; 2, lower box. DETAILED DESCRIPTION

[0032] The drawings of the present invention are only for illustrative purposes and should not be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; it is understandable to those skilled in the art that some well-known structures and their descriptions in the drawings may be omitted.

[0033] like Figure 1-3 As shown, the present invention discloses an asphalt-based carbon fiber reflector seat and a manufacturing method thereof. The raw material for manufacturing the reflector seat is an asphalt-based carbon fiber plate.

[0034] The reflector seat is divided into two parts, an upper box body 1 and a lower box body 2. The upper box body 1 is fixed on the lower box body 2, wherein: the rear end face of the upper box body 1 is an opening; mounting holes are arranged on the upper end face and the lower end face of the upper box body 1; the longitudinal section of the lower box body 2 is a trapezoid, which has a longer upper end face, a shorter lower end face and two front and rear inclined faces, both of which are openings, and two mounting holes are arranged on the longer upper end face along its length direction; after fixing, the mounting holes on the upper end face of the upper box body 1, the mounting holes on the lower end face of the upper box body 1 and the mounting holes on the rear side of the upper end face of the lower box body 2 are concentric.

[0035] A U-shaped groove is provided on the front side of the bottom jointing plate of the upper box body 1. When the upper box body 1 is fixed to the lower box body 2, a wiring hole is formed by the top surface of the lower box body 2, the U-shaped groove and the bottom of the jointing plate at the front end of the upper box body 1. The wiring hole has an L-shaped structure. The upper box body and the lower box body are used as two boxes. After being fixed, a frame structure is formed. The structural strength is high, which ensures the optical performance and reliability of the reflector seat. The bottom of the front end of the upper box body is set as a wiring hole, and the rear end surface is an opening. The two inclined surfaces of the lower box body are openings, which can effectively ensure the heat dissipation of internal components. The opening design is more convenient to operate and can effectively improve its functionality.

[0036] Each box is made of several carbon fiber splicing plates connected by mortise and tenon technology. The carbon fiber splicing plates are cut from rectangular asphalt-based carbon fiber plates.

[0037] The asphalt-based carbon fiber board is made of asphalt-based carbon fiber unidirectional prepreg cloth, which is laminated and molded at angles of 0°, 45°, 90°, and 135°. The molding machine is set to a temperature of 150°C and a time of 3 hours. The above molding temperature and time are mainly used to eliminate the following defects. If the molding temperature is too low and the time is too short, delamination will occur: delamination usually occurs when the interlayer bonding force is insufficient or is subjected to external impact. If the molding temperature is too high or the time is too long, fiber breakage will occur: during processing or use, the carbon fiber may break, resulting in a decrease in local strength. And the temperature of 150°C and the time of 3 hours can also maximize the uniformity of the internal resin and avoid resin enrichment or depletion: in some areas, there may be too much resin (resin enrichment), while in other areas it may be insufficient (resin depletion). This uneven distribution will affect the overall performance of the material. It can also avoid internal bubbles: the air mixed in during the preparation process is not effectively removed, and the bubbles formed will reduce the mechanical properties of the material.

[0038] This laying method meets the mechanical properties of the product at different angles, increases its strength, and thus ensures the stability of the overall structure. -5 K -1 The thermal expansion coefficient of asphalt-based carbon fiber sheets is much lower than that of titanium alloys in the prior art, and can meet high-precision requirements, thereby effectively improving the optical performance of the reflector. The thermal expansion coefficient of asphalt-based carbon fiber sheets is usually low, however, the specific value will vary depending on factors such as the preparation process, fiber arrangement direction, and matrix material. Generally speaking, the thermal expansion coefficient of asphalt-based carbon fiber sheets can refer to the following ranges:

[0039] Along the fiber direction (longitudinal direction): The thermal expansion coefficient of asphalt-based carbon fiber sheets in the fiber direction is usually very low, sometimes even negative, ranging from -0.5 to 1.0×10 -6 K -1 between.

[0040] Perpendicular to the fiber direction (transverse): Perpendicular to the fiber direction, the coefficient of thermal expansion is usually higher, but still relatively low, about 5 to 10×10 -6 K -1 between.

[0041] These values ​​are approximate and the actual coefficient of thermal expansion may vary depending on the specific product and manufacturing process.

[0042] Factors affecting the thermal expansion coefficient: Fiber type and arrangement: Different carbon fiber types and arrangements will affect the overall thermal expansion performance. Manufacturing process: Different manufacturing processes (such as hot pressing, resin transfer molding, etc.) will affect the microstructure of the material, thereby affecting the thermal expansion performance.

[0043] In this scheme, the ply angles of 0°, 45°, 90°, and 135° are used to not only improve the structural strength of the asphalt-based carbon fiber sheet, but also to make its deformation relatively uniform in the longitudinal and transverse directions, both of which can reach 0.15×10 -5 K -1 The thermal expansion coefficient of carbon fiber is 2.5mm, which is 2.3mm. It is worth noting that during the ply manufacturing process, if the resin fails to completely fill the gaps between the carbon fibers, voids may form. The voids will reduce the strength and toughness of the material, so attention should be paid to void defects.

[0044] In the field of aerospace, especially in optical remote sensing equipment, carbon fiber reflector mounts can meet the equipment's requirements for light weight, high strength and high stability. Carbon fiber reflector mounts can reduce the weight of the equipment, while ensuring the normal operation of the reflector in complex environments (such as temperature changes, micrometeoroid impacts, etc.), providing reliable support for aerospace optical observation missions.

[0045] In practical applications, the thermal expansion deformation of the reflector base should not exceed 0.01% within the temperature range of -40°C to 80°C. The unit area weight of the asphalt-based carbon fiber sheet should not exceed 1.5kg / m 2 , with the characteristics of light weight and high strength. In order to ensure that the length change caused by thermal expansion does not exceed 0.01% of the initial length, we need to calculate the maximum allowable temperature change range according to the formula of linear thermal expansion. The given conditions are as follows: Taking the initial length Lo = 10cm = 0.1m as an example, the linear thermal expansion coefficient α = 0.15×10 -5 K -1 , the maximum allowable length change ratio is 0.01%;

[0046] The maximum permissible length change ΔLmax is:

[0047] ΔLmax=Lo×0.01%=0.1×0.0001=1×10 -5 m or 0.001 mm

[0048] Use the linear thermal expansion formula ΔL = L0 × α × ΔT to solve for the maximum allowable temperature change ΔTmax:

[0049] 1×10 -5 =0.1(0.15×10 -5 )ΔTmax

[0050] Solving this equation finally yields: ΔTmax≈66.67K or ℃

[0051] Based on the room temperature of 25℃, it means that starting from the base temperature of 25℃, the temperature can vary within the range of 25℃±66.67℃, that is, the temperature range is between -41.67℃ and 91.67℃, meeting the requirement that the length change ratio does not exceed 0.01% within the use range of -40℃ to 80℃.

[0052] Carbon fiber unidirectional prepreg, also known as unidirectional carbon fiber prepreg, is a resin-based carbon fiber reinforced composite material made by hot melting, coating, hot pressing, cooling, laminating, winding and other processes of epoxy resin glue and carbon fiber cloth. Carbon fiber unidirectional prepreg is a semi-finished product that is initially impregnated with epoxy resin and carbon fiber and is not cured. It can only be formed after being heated and cured after being made into a product. It has broad application prospects in the multifunctional structures of microelectronic equipment and satellites.

[0053] The thermal conductivity of asphalt-based carbon fiber composites is anisotropic, with an extremely low thermal expansion coefficient and lightweight characteristics. Traditional metal materials are not only heavy, but also have a high thermal expansion coefficient, which makes it difficult to meet the requirements of optical components. Carbon fiber has a low density and light weight, can maintain stable performance under different environmental conditions, and has good corrosion resistance. Along the fiber direction, carbon fiber has a high thermal conductivity, which makes it perform well in applications that require efficient heat conduction, such as radiators, thermal management materials, etc. The density of carbon fiber is relatively low, only 1.7g / cm 3 This makes it very popular in lightweight designs. Carbon fiber has high strength and modulus, making it suitable for structural parts that require high stiffness and strength.

[0054] The use of asphalt-based carbon fiber unidirectional prepreg can effectively reduce costs. The price of titanium alloy is usually higher than that of carbon fiber. The price of titanium alloy is about 80-120 US dollars per kilogram, while the price of carbon fiber is about 50-80 US dollars per kilogram. The material itself is cheaper. Titanium alloy is difficult to process and the manufacturing process is complicated. Although the manufacturing process of carbon fiber is also complicated, its price is relatively low. Titanium alloy is difficult to process and requires special processes and equipment, which increases its production cost.

[0055] The manufacturing method of the reflector seat specifically comprises the following steps:

[0056] The asphalt-based carbon fiber plate is processed once in a CNC machining center to process the rectangular carbon fiber plate into a carbon fiber splicing plate that can be connected with mortise and tenon joints. The first processing is mainly to avoid poor surface quality: such as scratches and dents on the surface. These problems not only affect the appearance, but may also become stress concentration points and reduce the durability of the material. The first cutting process can also eliminate interface defects: the interface between carbon fiber and matrix resin is the key to bonding. If the interface is poorly bonded, the material performance will be reduced. At the same time, the bonding strength can also be guaranteed. During the cutting process, the cutting parameters (such as feed speed, cutting depth, etc.) need to be precisely controlled to avoid damaging the material.

[0057] The processed carbon fiber splicing plate is spliced ​​into the upper box 1 and the lower box 2 through the mortise and tenon process. When the mortise and tenon connection is made, resin glue should be used for bonding to ensure the reliability of the mortise and tenon connection. After that, the upper box 1 and the lower box 2 will be bonded with resin glue, and the reflector seat will be assembled. During the drilling and milling process, the high-speed rotating tool may cause the material to be delaminated or the fiber to break. When using mechanical connections (such as bolts and rivets), it is necessary to pay attention to the design of the aperture and hole spacing to avoid cracks or delamination caused by stress concentration. The mortise and tenon process can effectively avoid the generation of more cracks or delamination defects on the reflector seat.

[0058] The assembled reflector seat is placed in a small curing oven for heating and curing at a temperature of 150°C for 2 hours.

[0059] After curing, the product is taken out and the CNC machining center is used to perform secondary finishing on each panel surface with an error of no more than ±0.01mm to achieve high-precision dimensions. The surface of the asphalt carbon fiber board may not be smooth enough and needs to be sanded or polished. Careful operation is required during the surface treatment process to avoid damaging the material surface or introducing new defects. Due to the anisotropy of the material, dimensional deviations are prone to occur during the processing process. High-precision processing equipment and strict measurement methods are required to ensure the dimensional accuracy of the final product.

[0060] like Figure 3As shown, the raw materials of asphalt-based fibers can be divided into mesophase asphalt fibers (high performance) and isotropic asphalt (general grade). The asphalt-based carbon fibers in this scheme are mesophase asphalt-based carbon fibers (tensile strength is not less than 3GPa, and tensile modulus is not less than 250GPa). The asphalt fibers obtained from isotropic asphalt are difficult to obtain graphite structure after high-temperature treatment, and are generally called general-grade asphalt fibers. The asphalt fibers obtained using mesophase asphalt have a typical graphite structure after graphitization, and have high strength and modulus, and are generally called high-performance asphalt-based carbon fibers. Because of the low strength and modulus of general-grade carbon fibers, their products are generally in the form of short fibers or carbon felt. The long fibers of mesophase asphalt-based carbon fibers, like PAN-based carbon fibers, have good processability.

[0061] The industrialization of pitch-based carbon fiber and PAN-based carbon fiber started almost at the same time. However, there is a big gap in total output. It is generally believed that this is because pitch-based carbon fiber is more difficult than polyacrylonitrile-based carbon fiber in the process of material preparation, spinning and oxidation, resulting in higher cost. However, in recent years, the technology of pitch-based carbon fiber products has been continuously improved, and the cost has been gradually reduced by the improvement, and the market has a growth trend. In addition, the high rigidity and high functional performance of pitch-based carbon fiber meet the needs of energy saving, and the application scope of pitch-based carbon fiber is also expanding.

[0062] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation methods of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An asphalt-based carbon fiber reflector mount, characterized in that: The reflector seat comprises: The upper box (1) and the lower box (2), each box is formed by splicing a number of carbon fiber splicing plates; The carbon fiber splicing plate is formed by cutting a rectangular asphalt-based carbon fiber plate; The asphalt-based carbon fiber plate is formed by layering and molding asphalt-based carbon fiber unidirectional prepreg at angles of 0°, 45°, 90°, and 135°.

2. The asphalt-based carbon fiber reflector mount according to claim 1, characterized in that: The asphalt-based carbon fiber sheet has a 0.15×10 -5 K -1 The coefficient of thermal expansion.

3. The asphalt-based carbon fiber reflector mount according to claim 1, characterized in that: The production process of the asphalt-based carbon fiber board includes: The asphalt-based carbon fiber prepreg was laid at angles of 0°, 45°, 90°, and 135°; The plates were molded in a molding machine at a molding temperature of 150°C for 3 hours.

4. The asphalt-based carbon fiber reflector mount according to claim 1, characterized in that: The carbon fiber splicing plate is spliced ​​into an upper box body (1) and a lower box body (2) by using a mortise and tenon process, and resin glue is used for bonding during the mortise and tenon connection.

5. The asphalt-based carbon fiber reflector mount according to claim 1, characterized in that: The thermal expansion deformation of the reflector seat does not exceed 0.01% within a temperature range of -40°C to 80°C.

6. A method for manufacturing an asphalt-based carbon fiber reflector seat according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Processing the asphalt-based carbon fiber plate in a CNC processing center to process the rectangular carbon fiber plate into a carbon fiber splicing plate that can be connected with mortise and tenon joints; S2, splicing the processed carbon fiber splicing plate into an upper box body (1) and a lower box body (2) by using a mortise and tenon process, and using resin glue for bonding during the mortise and tenon connection, and then using resin glue to bond the upper box body (1) and the lower box body (2), and the reflector seat is assembled and formed; S3, placing the assembled reflector seat into a curing furnace for heating and curing; S4. After curing, take it out and perform secondary finishing on each panel surface in the CNC machining center.

7. The method for manufacturing a pitch-based carbon fiber reflector seat according to claim 6, characterized in that: The pitch-based carbon fiber is a mesophase pitch-based carbon fiber.

8. The asphalt-based carbon fiber reflector mount according to claim 6, characterized in that: The tensile strength of the mesophase asphalt-based carbon fiber is not less than 3 GPa, and the tensile modulus is not less than 250 GPa.

9. The asphalt-based carbon fiber reflector mount according to claim 6, characterized in that: The bonding strength of the resin glue is not less than 10 MPa.

10. The asphalt-based carbon fiber reflector mount according to any one of claims 6 to 9, characterized in that: The precision error of the secondary finishing does not exceed ±0.01mm.

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