A kind of gradient buffer energy-absorbing aluminum honeycomb core material and its preparation method

Abstract

The application discloses a gradually-changing buffer energy-absorbing aluminum honeycomb core and a preparation method thereof. For a piece of the gradually-changing buffer energy-absorbing aluminum honeycomb core which is horizontally placed and in which the through-hole axes of all cells are perpendicular to the horizontal plane, the section of the cell wall is composed of an isosceles trapezoid part / isosceles triangle part and a rectangular part or is composed of a similar isosceles trapezoid part / similar isosceles triangle part and a rectangular part in the height direction H of the aluminum honeycomb part, and the wall thickness of the aluminum honeycomb core cell wall continuously transitions from narrow to wide to the rectangular part in the isosceles trapezoid part / similar isosceles trapezoid part or the isosceles triangle part / similar isosceles triangle part. The application changes the section of the cell wall of the aluminum honeycomb core into a combination of the (similar) isosceles trapezoid / (similar) isosceles triangle and the rectangle, wherein the isosceles trapezoid / isosceles triangle part is a processed part. When the section of the cell wall of the aluminum honeycomb core is the shape, the compression resistance value is proportional to the compression distance, and the aluminum honeycomb core is a gradually-changing buffer energy-absorbing aluminum honeycomb core.

Description

Technical Field

[0001] This invention relates to an energy-absorbing material, specifically to a gradient-type buffer energy-absorbing aluminum honeycomb core material and its preparation method. Background Technology

[0002] Aluminum honeycomb, as a porous material, has the characteristics of low equivalent density, relatively weak crushing strength, large compression stroke, stable average crushing load, no rebound, and controllable deformation, thus exhibiting good buffering performance.

[0003] Aluminum honeycomb cells come in various structural forms, such as rectangular, hexagonal, and rhombic. Among them, the regular hexagonal aluminum honeycomb structure is the most material-efficient, stable, has the largest volume, and the best rigidity for the same mass. Due to its structural stability, the hexagonal aluminum honeycomb core material can effectively disperse external forces and is widely used in energy-absorbing structures.

[0004] The structure of the hexagonal aluminum honeycomb core material is shown below. Figure 1 and Figure 2 Hexagonal aluminum honeycomb core material is composed of several such Figure 1 The cell composition shown is as follows: Figure 1 middle m Let be the side length. k Distance to opposite sides D Diagonal distance a For wall thickness, ... Figure 2 In this context, for each hexagonal aluminum honeycomb core material, L The length of the aluminum honeycomb block; W The width of the aluminum honeycomb block; H This represents the height of the aluminum honeycomb block.

[0005] However, the compressive strength of ordinary aluminum honeycomb cores remains relatively flat in the working zone after the extreme point. In contrast, automotive crash tests often utilize aluminum honeycomb cores with continuously varying compressive strength that is proportional to distance. This necessitates the design and fabrication of aluminum honeycomb cores to meet these requirements.

[0006] Regarding existing technologies for improving energy absorption efficiency, Chinese patent document CN 106081356A (application number 201610377565.0) discloses a honeycomb buffer device and design method for improving energy absorption efficiency. The honeycomb cell is divided into two regions: a folded region and an unfolded region. The honeycomb cell in the folded region is folded at the same angle or different angles once or multiple times in the opposite direction. Each fold is taken to measure the height of the honeycomb cell and the honeycomb cells in the folded region and connected in series. After being connected, they are arrayed in a plane perpendicular to the opposite direction. This can effectively reduce the peak stress of the honeycomb buffer device and improve the energy absorption efficiency of the honeycomb buffer device.

[0007] Chinese patent document CN 111231428A (201911282574.1) discloses a method for preparing high-density energy-absorbing aluminum honeycomb core material. The aluminum honeycomb core material is prepared by stretching. The honeycomb wall of the aluminum honeycomb core material is composed of two or more layers of aluminum alloy foil. The aluminum alloy foil layers are bonded together by adhesive. In this method, adhesive is applied to the surface of the first layer of aluminum alloy foil at the spacing of the hexagonal aluminum honeycomb core material to form an adhesive layer. The spacing D is three times the width L of the adhesive layer. Adhesive is applied to the surface of the second layer of aluminum alloy foil at the spacing of the width L of the adhesive layer to form an adhesive layer. Subsequent layers of aluminum alloy foil are coated with adhesive in the same manner as the second layer. When the layers of aluminum alloy foil are stacked together, the upper and lower positions of the first layer of aluminum alloy foil and the adhesive layer correspond to the upper and lower positions of the adhesive layers on the subsequent layers of aluminum alloy foil. The principle behind this patent for improving energy absorption performance is as follows: Multiple layers of aluminum alloy foil with a thickness ranging from 0.03mm to 0.08mm are bonded together using adhesive bonding. This increases the thickness of the honeycomb wall, improving the mechanical properties of the final honeycomb product. Because the assembled honeycomb arms are made of thin aluminum alloy foil bonded together, but not bonded as a whole at deformation points, the thin aluminum alloy foil deforms individually during stretching, significantly reducing stress and preventing cracking of the honeycomb nodes due to excessive stress. However, the above structure suffers from poor continuity. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to improve a gradually increasing buffer energy-absorbing aluminum honeycomb core material whose pressure resistance is proportional to the distance and the preparation method thereof.

[0009] The technical solution for achieving the first objective of this invention is a gradient buffer energy-absorbing aluminum honeycomb core material. For a horizontally placed gradient buffer energy-absorbing aluminum honeycomb core material in which the through-hole axes of all cells are perpendicular to the horizontal plane, in the height H direction of the aluminum honeycomb component, the cross-section of all cell walls is composed of isosceles trapezoidal portions and rectangular portions, or is composed of quasi-isosceles trapezoidal portions and rectangular portions. The longer base of the isosceles trapezoidal / quasi-isosceles trapezoidal portion is connected to the rectangular portion, and the connecting side dimension of the longer base and the rectangle is the same. Alternatively, the cross-section of all cell walls is composed of isosceles triangular portions and rectangular portions, or is composed of quasi-isosceles triangular portions and rectangular portions. The base of the isosceles triangular / quasi-isosceles triangular portion is connected to the rectangular portion, and the connecting side dimension of the base and the rectangle is the same.

[0010] In the aforementioned aluminum honeycomb core material, the cell wall thickness transitions continuously from narrow to wide in the isosceles trapezoidal / quasi-isosceles trapezoidal segment or isosceles triangle / quasi-isosceles triangle segment until the rectangular portion.

[0011] The technical solution to achieve the second objective of this invention is the preparation method of the gradient buffer energy-absorbing aluminum honeycomb core material as described above, which includes the following steps:

[0012] ① Place the aluminum honeycomb sample to be processed into the prepared acid solution, chemically corrode it in the acid solution for a period of time, then pull it out, wash and dry it; measure and calculate the reduction in wall thickness, and calculate the corrosion rate of the aluminum honeycomb sample to be processed in the acid solution, c um / s.

[0013] ②According to t= ( ab ) / c as well as V=h / t The sinking speed of the aluminum honeycomb component is calculated using two formulas. V Or increase speed V In the formula a This represents the dimensions of the cell walls before corrosion. b This is the narrowest dimension after the cell wall of the honeycomb is etched. h is The heights a, b, and h of the isosceles trapezoid / quasi-isosceles trapezoid or triangle / quasi-triangle section are determined according to processing requirements.

[0014] The process employs a submerged acid etching method. The aluminum honeycomb component to be processed is placed vertically in a motor-driven basket. The aluminum honeycomb product is immersed downwards into the acid solution at a speed of V. When the submerged height reaches the value h, the basket is lifted to remove the aluminum honeycomb component from the acid solution. Then, it is washed with pure water and dried.

[0015] Alternatively, a lifting acid etching method can be used; the aluminum honeycomb part to be processed is placed vertically in a motor-driven basket and immersed in acid. The vertical immersion depth of the aluminum honeycomb product is h, and the motor drives the basket at a speed of... V Lift it upwards until the aluminum honeycomb parts are removed from the acid solution, then rinse them clean with pure water.

[0016] ③ Immerse the aluminum honeycomb parts that have undergone acid etching in step ② in an anti-corrosion solution, take them out, wash them with deionized water, and dry them to obtain the finished product.

[0017] In step ① above, first calculate the difference between the thickness before corrosion and the thickness after corrosion, and divide the difference by the corrosion time to obtain c.

[0018] In steps ② and ③ above, the drying temperature is 30–95℃.

[0019] This invention has positive effects:

[0020] (1) In this invention, the cross-section of the cell wall of the aluminum honeycomb core material is designed from the traditional rectangle to a combination of (like) isosceles trapezoid and rectangle, or a combination of (like) triangle and rectangle, wherein the (like) isosceles trapezoid segment and the (like) triangle segment are the processed segments; when the cross-section of the cell wall of the aluminum honeycomb core material is the aforementioned shape, the compressive strength is proportional to the compression distance, and it is a gradually changing buffer energy-absorbing aluminum honeycomb core material.

[0021] (2) This invention employs an acid etching method to process gradient buffer energy-absorbing aluminum honeycomb core material: First, the corrosion rate of the aluminum honeycomb core material to be processed in the corresponding acid solution is tested and calculated. Then, the immersion rate or lifting rate is calculated based on the corrosion rate and the dimensional requirements of the cell wall cross-section. Next, the aluminum honeycomb block to be processed is continuously immersed into the acid solution according to the immersion rate, or the processing section of the aluminum honeycomb block to be processed is first immersed into the acid solution, and then continuously lifted upwards according to the lifting rate, ultimately obtaining the gradient buffer energy-absorbing aluminum honeycomb core material. The method of this invention can complete the processing of the target size by controlling the lifting rate. The processing method has high precision and is suitable for large-scale factory production. Attached Figure Description

[0022] Figure 1 This is a single cell diagram of a regular hexagonal aluminum honeycomb block.

[0023] Figure 2 This is a schematic diagram of the shape of a regular hexagonal aluminum honeycomb block.

[0024] Figure 3 This is a cross-sectional view of the aluminum honeycomb wall before corrosion.

[0025] Figure 4 This is a cross-sectional view of the honeycomb wall in Example 1.

[0026] Figure 5 The force-deflection curves are for the static test of AL 5052 in GB 20071.

[0027] Figure 6 The force-deflection curves are for the static test of AL 3003 in GB 20071.

[0028] Figure 7 This is a static test force-displacement curve of the gradient buffer energy-absorbing aluminum honeycomb core material of Example 1.

[0029] Figure 8 This is a static test force-displacement curve of the gradient buffer energy-absorbing aluminum honeycomb core material in Example 2. Detailed Implementation

[0030] The following describes some of the possible embodiments of the present invention, intended to provide a basic understanding of the invention, and is not intended to identify the key or decisive elements of the invention or limit the scope of protection. It is readily understood that, based on the technical solutions of the present invention, those skilled in the art can propose other interchangeable implementations without altering the essential spirit of the invention. Therefore, the following detailed descriptions and accompanying drawings are merely illustrative of the technical solutions of the present invention and should not be considered as the entirety of the invention or as a limitation or restriction of the technical solutions of the present invention.

[0031] (Example 1)

[0032] For a horizontally placed, gradient-patterned, energy-absorbing aluminum honeycomb core material, the through-hole axes of all cells are perpendicular to the horizontal plane. In the height H direction, any vertical cross-section of the cell wall is either a combination of an isosceles trapezoid and a rectangle, or a combination of an isosceles trapezoid and a rectangle. The vertical cross-section is a combination of an isosceles trapezoid and a rectangle because the two sides of the cell wall are not smooth, but the trend of gradually widening from narrow to wide in one direction is not affected.

[0033] See Figure 3 In the height H direction, the cross-section of the cell wall of a normal aluminum honeycomb core material is rectangular, that is, the wall thickness is the same from top to bottom.

[0034] See Figure 4 In this embodiment, the cross-section of the cell wall of the gradient buffer energy-absorbing aluminum honeycomb core material consists of an isosceles trapezoid / quasi-isosceles trapezoid portion and a rectangular portion. The longer lower base of the isosceles trapezoid / quasi-isosceles trapezoid portion is connected to the rectangular portion, and the connecting side (the side connected to the isosceles trapezoid) has the same size. In the figure, the lower base of the isosceles trapezoid / quasi-isosceles trapezoid portion is connected to the rectangular portion; in the isosceles trapezoid / quasi-isosceles trapezoid segment, the wall thickness continuously transitions from narrow at the top to wide at the bottom.

[0035] The shape of the cell is not limited; rectangles, hexagons, rhombuses, etc. can all be selected. Considering the stability of the hexagonal aluminum honeycomb core material structure, this invention is introduced using hexagonal aluminum honeycomb core material as an example in this embodiment and the following embodiments.

[0036] The gradient buffer energy-absorbing aluminum honeycomb core material of the present invention is prepared by acid etching.

[0037] See Figure 4 For the cell wall of the gradient buffer energy-absorbing aluminum honeycomb core material in this embodiment, the thickness of one end (wide end) of the cell wall is denoted as a, the thickness of the other end (narrow end) is denoted as b, the total height of the cell wall is denoted as H, the height of the isosceles trapezoidal part is denoted as h, and the height of the rectangular part is Hh; the thickness a at the wide end is both the thickness of the bottom of the isosceles trapezoidal part and the thickness of the rectangular part.

[0038] When using the acid etching method, the aluminum honeycomb core material is hoisted and fixed, then immersed in acid at a certain rate. After processing, it is immediately lifted and post-treated. Alternatively, the aluminum honeycomb core material is hoisted and fixed, then quickly immersed in acid, then lifted at a certain rate, and post-treated after being removed from the acid.

[0039] In the following description, the point at the top of the aluminum foil that is not immersed in the acid solution to form the cell wall is called P0, the critical point between the aluminum foil and the liquid surface is called P1, the midpoint of the aluminum foil that enters the liquid is called P2, and the point where the aluminum foil first enters the liquid (or stays in the liquid for the longest time) is called P3. The aluminum foil in the P0-P1 segment is not corroded and thinned, point P3 thins the most, and point P2 thins by half the amount of point P3.

[0040] Acid etching is an exothermic reaction. To reduce the impact of the exothermic reaction, the temperature rise and the decrease in acid concentration on the corrosion rate, the amount of acid in the acid pool is excessive, and the impact of the temperature rise and the decrease in acid concentration on the corrosion rate is ignored; or online real-time monitoring of concentration and temperature is adopted to replenish acid and control the temperature in a timely manner.

[0041] The relationship between corrosion time and the required aluminum honeycomb wall thickness is as follows: t= ( ab ) / c .

[0042] In the above formula: a The dimensions of the cell walls before corrosion are shown in μm. b This represents the narrowest dimension of the cell wall after etching, expressed in μm. c The corrosion rate is the amount of corrosion per unit time of the aluminum honeycomb wall, expressed in μm / s.

[0043] in a , b The value of c is known. The value of c is obtained through experimental testing and calculation: The aluminum honeycomb core sample to be processed is placed in a basket driven by a motor and immersed in an acid solution with constant concentration and temperature. It is chemically corroded in the acid solution for 50-100 seconds. The motor is then quickly pulled out, the sample is cleaned with pure water, and then dried in an oven at a temperature of 30-95℃. The reduction in wall thickness is measured and calculated with a micrometer, and the corrosion rate c (unit: μm / s) is calculated per unit time.

[0044] The formula for calculating the speed at which aluminum honeycomb cells are immersed downwards into the liquid or lifted upwards from the acid solution is: V=h / t The unit is mm / s.

[0045] h The height of the aluminum honeycomb section during processing is also the height of the isosceles trapezoidal part, in mm. t The corrosion time is expressed in seconds (s).

[0046] The preparation method using acid etching includes the following steps:

[0047] ① Place the aluminum honeycomb sample to be processed into a basket driven by a motor and immerse it in the prepared acid solution. Chemically corrode it in the acid solution for 50-100 seconds. Quickly pull it out with the motor, clean it with pure water, and then put it into an oven at a temperature of 30-95℃ to dry it. Measure and calculate the reduced wall thickness with a micrometer, and calculate the corrosion rate c (unit: μm / s).

[0048] ②According to t= ( ab ) / c as well as V=h / t The sinking speed of the aluminum honeycomb component is calculated using two formulas. V(First type of acid etching) or increasing speed V (Second type of acid etching).

[0049] For the first acid etching method, the aluminum honeycomb part to be processed is placed vertically in a motor-driven basket (the axis of the honeycomb holes is perpendicular to the horizontal plane). The aluminum honeycomb product is immersed downwards into the acid solution at a speed of V. When the sinking position reaches point P1, the basket is quickly lifted (the lifting is completed within 5 seconds) so that the aluminum honeycomb part is removed from the acid solution. Then it is cleaned with pure water and dried in an oven at a temperature of 30-95℃. The narrowest wall thickness b measured by micrometer is basically consistent with the design requirement value.

[0050] For the second acid etching method, the aluminum honeycomb part to be processed is placed vertically in a motor-driven basket (with the honeycomb hole axis perpendicular to the horizontal plane), and quickly (within 5 seconds to reach the designated position) immersed in the acid solution. The vertical immersion depth of the aluminum honeycomb product is h. The motor drives the basket to slowly lift it upward at a speed V until the aluminum honeycomb part is removed from the acid solution. Then it is cleaned with pure water and dried in an oven at a temperature of 30-95℃. The narrowest wall thickness b measured by micrometer is basically consistent with the design requirement value.

[0051] ③ Immerse the aluminum honeycomb parts that have undergone acid etching in step ② in an anti-corrosion solution at 20-95℃ for 60-120 seconds. After removing them, wash the aluminum honeycomb parts with deionized water at room temperature and dry them in an oven at 30-95℃ to obtain the finished product.

[0052] Specifically, the preparation method is introduced using AL 5052 as an example:

[0053] ① The inscribed circle has a diameter of 3 / 4 inch and a wall thickness of... a A 50µm, hexagonal aluminum honeycomb sample made of 5052 material, with dimensions of 500*250*500 mm, was placed in a motor-driven basket and immersed in a 1-20 wt% hydrochloric acid solution at 20℃~95℃ to a depth of 5-10 mm. ， Chemical corrosion for 60 seconds; the motor is quickly pulled out, rinsed with pure water, and then dried in an oven at 30-95℃; the wall thickness is measured to be 44µm with a micrometer, and the corrosion rate is calculated to be c=0.1µm / s.

[0054] In addition to the 1-20 wt% hydrochloric acid solution mentioned above, other acids that can react with aluminum can also be used, such as sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, etc.

[0055] For the aforementioned honeycomb with an inscribed circle diameter of 3 / 4 inch, the cell wall thickness ranges from 0.03 to 0.085 mm. For honeycombs with other diameters, the cell wall thickness should be adjusted accordingly to meet the mechanical performance requirements.

[0056] ② In this embodiment, the wall thickness b is required to be 4µm. t=( ab ) / c= 460s.

[0057] Height of the isosceles trapezoidal section of the aluminum honeycomb component h= 300mm ， according to V = h / t = 0. 65mm / s.

[0058] A submerged acid etching method was employed. The hexagonal aluminum honeycomb components were fixedly placed in a motor-driven basket (with the honeycomb hole axis perpendicular to the horizontal plane), and then... 0. The aluminum honeycomb component was immersed in the acid solution at a descent speed of 65 mm / s. When the component had descended to a height of 300 mm, the basket was quickly pulled out of the solution and immediately rinsed with pure water, then dried. The wall thickness at point P3 was measured to be 4.5 μm, at point P2 27.5 μm, and at point P1 50 μm. This product is designated as test piece 1.

[0059] A lifting-type acid etching method is employed. A regular hexagonal aluminum honeycomb component is fixedly placed in a motor-driven basket (with the honeycomb hole axis perpendicular to the horizontal plane) and rapidly immersed in acid. The vertical immersion depth of the aluminum honeycomb component is 300mm. The motor drives the basket at a high speed... V = 0. Slowly lift the aluminum honeycomb parts upwards at 65 mm / s until they are removed from the acid solution; then clean them with pure water and dry them in an oven at a temperature of 30–95°C; measure the wall thickness at point P3 with a micrometer, which is 4.4 μm, at point P2 it is 27.5 μm, and at point P1 it is 50 μm.

[0060] ③ Immerse the aluminum honeycomb parts that have undergone acid etching in step ② in an anti-corrosion solution at 20-95℃ for 60-120 seconds. After removing them, wash the aluminum honeycomb parts with deionized water at room temperature and dry them in an oven at 30-95℃ to obtain the finished product.

[0061] (Example 2)

[0062] This embodiment uses an aluminum honeycomb component made of AL 3003 aluminum alloy as an example to introduce the preparation method, including the following steps:

[0063] ① The inscribed circle has a diameter of 3 / 4 inch and a wall thickness of... a A hexagonal aluminum honeycomb sample made of 3003 material, measuring 85µm and with dimensions of 500*250*440mm, was placed in a motor-driven basket and immersed in a 1-20wt% hydrochloric acid solution at 20℃~95℃ to a depth of 5-10mm. ， Chemical corrosion for 100 seconds; the motor is quickly pulled out, rinsed with pure water, and then dried at 30-95℃; the wall thickness is measured to be 73µm with a micrometer, and the corrosion rate is calculated to be c=0.12µm.

[0064] ②In this embodiment, the wall thickness b is required to be 5µm. t= ( ab ) / c=666.7s.

[0065] Height of the isosceles trapezoidal section of the aluminum honeycomb component h= 240mm ， According to V =h / t=0. 36mm / s.

[0066] A submerged acid etching method was employed. The 3003 stainless steel hexagonal aluminum honeycomb components were fixedly placed in a motor-driven basket (with the honeycomb hole axis perpendicular to the horizontal plane), and then... 0. The aluminum honeycomb component was immersed in the acid solution at a descent speed of 36 mm / s. When the component had descended to a height of 240 mm, the basket was quickly pulled out of the solution and immediately rinsed with pure water, then dried. The wall thickness at point P3 was measured to be 6 μm, at point P2 46 μm, and at point P1 85 μm. This product is designated as test piece 2.

[0067] A lifting-type acid etching method is employed. A regular hexagonal aluminum honeycomb component is fixedly placed in a motor-driven basket (with the honeycomb hole axis perpendicular to the horizontal plane) and rapidly immersed in acid. The vertical immersion depth of the aluminum honeycomb component is 240mm. The motor drives the basket at a high speed... V = 0. Slowly lift the aluminum honeycomb parts upwards at a speed of 36 mm / s until they are removed from the acid solution; then clean them with pure water and dry them in an oven at a temperature of 30–95°C.

[0068] ③ Immerse the aluminum honeycomb parts that have undergone acid etching in step ② in an anti-corrosion solution at 20-95℃ for 60-120 seconds. After removing them, wash the aluminum honeycomb parts with deionized water at room temperature and dry them in an oven at 30-95℃ to obtain the finished product.

[0069] (Example 3)

[0070] For a horizontally placed, gradient-patterned, energy-absorbing aluminum honeycomb core material, the through-hole axes of all cells are perpendicular to the horizontal plane. In the height H direction, the vertical cross-section of all cell walls is a combination of isosceles triangles and rectangles, or a combination of isosceles triangles and rectangles. The vertical cross-section is a combination of isosceles triangles and rectangles because the two sides of the cell walls are not smooth, but the trend of gradually widening from narrow to wide in one direction is not affected.

[0071] In this embodiment, the cross-section of the cell wall of the gradient buffer energy-absorbing aluminum honeycomb core material consists of isosceles triangles / quasi-isosceles triangles and rectangular sections. The lower base of the isosceles triangle / quasi-isosceles triangle section is connected to the rectangular section, and the connecting side (the side connected to the triangle) of the lower base and the rectangle has the same size. The lower base of the isosceles triangle / quasi-isosceles triangle section is connected to the rectangular section; in the isosceles triangle / quasi-isosceles triangle section, the wall thickness transitions continuously from narrow at the top to wide at the bottom.

[0072] Compared to the gradient buffer energy-absorbing aluminum honeycomb core material of Example 1, when the top of the gradient buffer energy-absorbing aluminum honeycomb core material of Example 1 becomes infinitely smaller to a point, its (quasi) isosceles trapezoidal part becomes the (quasi) isosceles triangular part described in this embodiment.

[0073] The processing method of the gradient buffer energy-absorbing aluminum honeycomb core material in this embodiment is the same as that in Embodiment 1, in the calculation t= ( ab When ) / c, b=0.

[0074] (Experimental example)

[0075] In GB 20071, the side-impact moving deformable barrier (MDB) requires the force-deflection standard curve of the aluminum honeycomb block for static testing as follows: Figure 5 (AL 5052) and Figure 6 As shown in (AL 3003), the compressive strength is directly proportional to the compression distance.

[0076] Test specimen 1 prepared in Example 1 and test specimen 2 prepared in Example 2 were tested according to the method in part C.4 of Appendix C of GB 20071. The static test force-displacement curve of test specimen 1 is shown in [reference needed]. Figure 7 The static test force-displacement curve of test piece 2 is shown in the figure. Figure 8 This demonstrates that the compressive strength of the aluminum honeycomb component prepared by this invention is proportional to the compression distance, thus meeting the requirements of the impact test.

Claims

1. A method for preparing a gradient buffering energy-absorbing aluminum honeycomb core material, characterized in that: the structure of the gradient buffering energy-absorbing aluminum honeycomb core material is that, for a piece of the gradient buffering energy-absorbing aluminum honeycomb core material horizontally placed with the through-hole axes of all cells being perpendicular to the horizontal plane, the cross sections of all cell walls are composed of isosceles trapezoidal parts and rectangular parts, or are composed of similar isosceles trapezoidal parts and rectangular parts, the longer base of the isosceles trapezoidal / similar isosceles trapezoidal part is connected with the rectangular part, and the connecting edge of the longer base and the rectangular part has the same size; or the cross sections of all cell walls are composed of isosceles triangular parts and rectangular parts, or are composed of similar isosceles triangular parts and rectangular parts, the base of the isosceles triangular / similar isosceles triangular part is connected with the rectangular part, and the connecting edge of the base and the rectangular part has the same size; and the method comprises the following steps: ① placing a sample aluminum honeycomb piece to be processed in prepared acid solution, taking out the sample after chemical corrosion in the acid solution for a period of time, washing and drying, measuring and calculating the reduced wall thickness, and calculating the corrosion speed c um / s of the aluminum honeycomb piece to be processed in the acid solution; a-b V = h / t h is the height of the aluminum honeycomb piece to be processed; V is the sinking speed of the aluminum honeycomb piece to be processed in the acid solution; and h is the sinking height of the aluminum honeycomb piece to be processed in the acid solution; ② adopting a sinking acid etching mode, vertically placing the aluminum honeycomb piece to be processed in a basket driven by a motor, immersing the aluminum honeycomb product into the acid solution at the speed V, lifting the basket when the sinking height reaches the value h, so that the aluminum honeycomb piece is separated from the acid solution, and then washing and drying the aluminum honeycomb piece with pure water; and ③ soaking the aluminum honeycomb piece after the acid etching treatment in step ② in an anti-corrosion liquid, washing the aluminum honeycomb piece with deionized water after taking out, and drying to obtain a finished product.

2. The method for preparing the gradient buffering energy-absorbing aluminum honeycomb core material according to claim 1, characterized in that: in step ①, the difference between the thickness before corrosion and the thickness after corrosion is calculated first, and then the difference is divided by the corrosion time to obtain c.

3. The method for preparing the gradient buffering energy-absorbing aluminum honeycomb core material according to claim 1, characterized in that: in steps ② and ③, the drying temperature is 30-95℃. ​ ②According to t= ( ​ ) c and ​ Two formulas are used to calculate the sinking speed V or the lifting speed V of the aluminum honeycomb; wherein a is the size of the honeycomb cell wall before corrosion, b is the narrowest size of the honeycomb cell wall after corrosion, ​ the height of the isosceles trapezoid / similar isosceles trapezoid part or the triangle / similar triangle part, and a, b, h are determined according to the processing requirements. ​ Or adopt the lifting type acid etching way; the aluminum honeycomb part to be processed is vertically placed in the basket dragged by the motor, immersed in the acid liquid, the immersion depth of the aluminum honeycomb product in the vertical direction is h, the basket is driven by the motor to ascend at a speed V upward until the aluminum honeycomb part is separated from the acid liquid, and then cleaned with pure water. ​ ​ ​ ​ ​

Images