A method and application of modifying the interface of fiber metal laminates by physical-chemical synergy

Abstract

A method and application of modifying the interface of a fiber metal laminate through physical-chemical synergistic modification. The present invention belongs to the field of composite material preparation. The purpose of the present invention is to solve the technical problem that the existing fiber metal laminate interface modification method has limited effect on improving the interface bonding strength. The method of the present invention: firstly sandblast the metal surface, then immerse it in an ethanol solution of a rare earth metal salt for ultrasonic immersion, then add resin and carbon nanotubes to continue ultrasonic immersion; then take it out, dry the treated metal, then rinse it with ethanol, and then dry it to complete the modification. The present invention introduces a resin transition layer with good compatibility with the matrix resin on the metal surface by chemical bonding and grafts carbon nanotubes, so as to synergistically optimize the interface between the metal and the resin, improve the interface bonding strength and overall mechanical properties of the composite material, so as to meet the needs of the marine and aerospace fields.

Description

Technical Field

[0001] The invention belongs to the field of composite material preparation, and in particular relates to a method for modifying the interface of a fiber metal laminate through physical-chemical synergy and an application thereof. Background Art

[0002] Fiber metal laminates are new composite materials that combine fiber-reinforced resin-based composite materials with high specific strength and modulus with metal sheets with high damage tolerance and impact resistance. They have been widely used in aerospace, shipbuilding and other industries.

[0003] The mature glass fiber reinforced aluminum alloy laminates used on the A380 and Boeing 777 are suitable for operating temperatures below 180°C, which is not enough to meet the high temperature resistance requirements of high-speed aircraft skins. Graphite / carbon reinforced titanium alloy laminates can provide material stability for future high-speed aerospace vehicles. At the same time, polyetheretherketone is a high-performance thermoplastic engineering plastic with excellent mechanical properties, chemical resistance and thermal stability, and can work for a long time at high temperatures up to 250°C. Therefore, the preparation of composite materials by combining polyetheretherketone, lightweight and high-strength carbon fiber, and high stiffness and creep-resistant titanium alloys has become one of the promising materials for future aviation high-speed aircraft applications.

[0004] Although the advantages of metal laminates are numerous, due to the difference between the thermophysical properties between metal and polymer, it is difficult to produce strong bonding at the interface, which reduces the interface adhesion strength and the stress transfer efficiency at the interface, further hindering the release of its overall performance potential, limiting its application. Therefore, it is necessary to surface treat the metal to improve the interface bonding strength. CN116262384A discloses a fiber metal laminate interface modification method, specifically first sandblasting the metal surface, then soaking it with an ethanol solution of a rare earth metal salt, arranging a layer of resin film between the metal and the prepreg after drying, and finally hot pressing, but the method improves the interface by enhancing the mechanical engagement mode, and the improvement for the interface bonding strength is limited, and the interface bonding strength cannot be further improved to meet the needs of the marine and aerospace fields. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problem that the existing fiber metal laminate interface modification method has limited effect on improving the interface bonding strength, and to provide a method and application of modifying the fiber metal laminate interface through physical-chemical synergistic modification.

[0006] One of the objects of the present invention is to provide a method for modifying the interface of a fiber metal laminate by physical-chemical synergy, the method comprising the following process:

[0007] S1: First, the metal surface is sandblasted, then immersed in an ethanol solution of rare earth metal salts for ultrasonic soaking, and then resin and carbon nanotubes are added and ultrasonic soaking is continued;

[0008] S2: Take out, dry the treated metal, then rinse with ethanol, and dry again to complete the modification.

[0009] Preferably, the sandblasting parameters in S1 are: 40-60 mesh corundum sand is used, the blasting distance is 90-170 mm, the blasting pressure is 0.2-0.5 MPa, and the blasting time is 15-30 s.

[0010] Preferably, the concentration of the ethanol solution of the rare earth metal salt in S1 is 0.3-0.8 wt.%.

[0011] Preferably, the rare earth metal salt in S1 is selected from chlorides of rare earth elements.

[0012] More preferably, the rare earth elements include Ce, La, and Pr.

[0013] Preferably, the resin in S1 is polyetherimide (PEI), and the added amount is 0.5-1.0 wt.% of the ethanol solution of the rare earth metal salt.

[0014] Preferably, the carbon nanotubes in S1 are carboxylated carbon nanotubes, and the added amount is 0.1-1.0 wt.% of the ethanol solution of the rare earth metal salt.

[0015] Preferably, the ultrasonic immersion parameters in S1 are: power of 80-100 W, frequency of 40-50 Hz, and time of 15-60 min.

[0016] Preferably, the drying temperature in S2 is 60-80° C. and the drying time is 1-6 h.

[0017] Preferably, S2 is rinsed with ethanol 1-4 times.

[0018] The second object of the present invention is to provide a method for preparing a high-performance fiber metal laminate, wherein the method for preparing the fiber metal laminate is carried out according to the following steps:

[0019] The modified metal and prepreg CFRTP in the above method are mixed according to [M / 0 3 / M / 0 3 / M] unidirectional ply structure is laid, and a layer of PEEK film is stacked between each layer of metal and prepreg CFRTP, followed by hot pressing to obtain a fiber metal laminate.

[0020] The [M / 0 3 / M / 0 3 / M] where M stands for metal, 0 3The laying angle of the representative prepreg is 0° and the number of laying layers is 3.

[0021] The third object of the present invention is to provide a fiber metal laminate produced by the above method, wherein the fiber metal laminate has an interface shear strength of ≥35 MPa, a bending strength of ≥1900 MPa, and an interlaminar shear strength of ≥90 MPa.

[0022] A fourth object of the present invention is to provide an application of a fiber metal laminate produced by the above method, wherein the fiber metal laminate is applied in the marine and aerospace fields.

[0023] Compared with the prior art, the present invention has the following significant effects:

[0024] The present invention improves the stress distribution at the interface and inhibits crack propagation by introducing carbon nanotubes at the interface. At the same time, a resin transition layer with good compatibility with the matrix resin is introduced on the metal surface by chemical bonding, thereby synergistically optimizing the interface between the metal and the resin, improving the interface bonding strength and overall mechanical properties of the composite material, and meeting the needs of the marine and aerospace fields. The specific advantages are as follows.

[0025] (1) The present invention proposes a method for modifying the interface of a fiber metal laminate. First, the metal surface is activated by sandblasting and an ethanol solution of a rare earth metal salt. The rare earth ions on the activated metal surface are coordinated with the transition layer resin and carbon nanotubes to construct a carbon nanotube network on the metal surface, thereby improving the wettability of the metal surface and effectively improving the bonding strength between the metal and the resin in the fiber metal laminate.

[0026] (2) The present invention also proposes a fiber metal laminate having both high interface strength and mechanical properties, which is obtained by modifying the metal according to the above method, so that the obtained fiber metal laminate has an interface shear strength of ≥35 MPa, a bending strength of ≥1900 MPa, and an interlaminar shear strength of ≥90 MPa. It has excellent comprehensive performance, meets the requirements for high-speed aircraft skin material selection, and can be used in the aerospace field. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a SEM image of the surface morphology of the TA2 titanium alloy after being treated in step (2) of the embodiment of the present invention;

[0028] Figure 2a This is the XPS O1s spectrum of the TA2 titanium alloy surface after being treated in step (2) of the embodiment of the present invention;

[0029] Figure 2b This is the XPS N1s spectrum of the TA2 titanium alloy surface after being treated in step (2) of the embodiment of the present invention;

[0030] Figure 3This is a comparison diagram of the apparent contact angles of deionized water and diiodomethane on the surface of a TA2 titanium alloy plate before and after treatment in step (2) of an embodiment of the present invention;

[0031] Figure 4 This is a comparison diagram of the surface energy of the TA2 titanium alloy plate before and after the treatment in step (2) of the embodiment of the present invention;

[0032] Figure 5 This is a comparison diagram of the interface bonding strength between the titanium alloy plate and the resin matrix in the fiber metal laminate prepared in the embodiment of the present invention and the comparative example;

[0033] Figure 6 It is a comparison chart of the bending strength and interlaminar shear strength tests of the fiber metal laminates prepared by the embodiment of the present invention and the comparative example. Implementation

[0034] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0036] The terms "comprising," "including," "having," "containing," or any other variations thereof, as used in the following examples, are intended to cover a non-exclusive inclusion. For example, a composition, step, method, article, or apparatus comprising the listed elements is not necessarily limited to only those elements, but may include other elements not expressly listed or inherent to such composition, step, method, article, or apparatus.

[0037] When equivalent, concentration or other value or parameter is represented by the range limited by range, preferred range or a series of upper preferred value and lower preferred value, this should be understood as specifically disclosing all ranges formed by any pairing of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether the scope is disclosed separately. For example, when disclosing range "1 to 5", described range should be interpreted as including range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc. When numerical range is described in this article, unless otherwise stated, the scope is intended to include its end value and all integers and fractions within the scope. In the present application specification and claims, range limitation can be combined and / or interchanged, if these ranges are not otherwise stated, include all sub-ranges contained therein.

[0038] The indefinite articles "a" and "an" before the elements or components of the present invention have no limitation on the quantity requirements (i.e. the number of occurrences) of the elements or components. Therefore, "a" or "an" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the quantity obviously refers to the singular form only. Example

[0039] The preparation method of the high performance fiber metal laminate of this embodiment is carried out according to the following steps:

[0040] (1) First, the surface of the TA2 titanium alloy plate was sandblasted with 60-mesh corundum sand at a blasting distance of 120 mm, a blasting pressure of 0.2 MPa, and a blasting time of 20 s. It was then ultrasonically cleaned in a 30 ℃ acetone solution for 30 min and dried in an 80 ℃ oven for 8 h. The resulting product was recorded as S-Ti.

[0041] (2) First, prepare a 0.5 wt.% CeCl 3 of ethanol solution;

[0042] Then, the TA2 titanium alloy plate after sandblasting in step (1) was immersed in CeCl 3 ethanol solution, and ultrasonically treated at 100 W and 40 Hz for 60 min;

[0043] Subsequently, PEI and carboxylated carbon nanotubes were added to the above treatment solution at an addition amount of 1.0 wt.% and 0.5 wt.%, respectively, and ultrasonic treatment was continued at a power of 100 W and a frequency of 40 Hz for 60 min;

[0044] Finally, the treated TA2 titanium alloy was dried in an oven at 80 °C for 4 h, then rinsed with ethanol 4 times, and then dried in an oven at 80 °C for 6 h to complete the modification. The obtained product was recorded as SPC0.5-Ti.

[0045] (3) First, the TA2 titanium alloy plate (SPC0.5-Ti) and prepreg CFRTP (Jiangsu Junhua Special Engineering Plastics Products Co., Ltd.) treated in step (2) were mixed according to [M / 0 3 / M / 0 3 / M] unidirectional ply structure, wherein the [M / 0 3 / M / 0 3 / M] where M stands for metal, 0 3 The laying angle of the representative prepreg is 0°, the number of layers is 3, and a layer of PEEK film is laminated between each layer of TA2 titanium alloy plate and prepreg CFRTP;

[0046] Subsequently, hot pressing is carried out, and the hot pressing process is as follows: starting from room temperature, heating to 390°C at a rate of 10°C / min and then keeping warm for 30 min, then cooling to 300°C and keeping warm for 30 min, and then continuing to cool to 170°C and keeping warm for 30 min, and finally cooling to room temperature. The cooling rate of the cooling process is always maintained at 1°C / min, and the pressure is maintained at 5 MPa throughout the process to obtain a fiber metal laminate.

[0047] First, the SPC0.5-Ti surface obtained in step (2) was subjected to morphological analysis. Figure 1 As shown, from Figure 1 It can be seen that after treatment, the surface of the titanium alloy is evenly covered with a uniform and dense carbon nanotube network, which effectively improves the surface roughness of the titanium alloy and provides a basis for the mechanical meshing with the resin.

[0048] To verify that rare earth elements were successfully introduced into the titanium alloy surface, the SPC0.5-Ti surface obtained in step (2) was subjected to XPS analysis, and the obtained element spectrum is shown in Figure 2. As can be seen from Figure 2, the presence of Ce-O bonds and Ce-N bonds were detected in the O1s and N1s spectra of the surface of the modified TA2 titanium alloy plate. This phenomenon proves that under the action of cerium ions, PEI, carbon nanotubes and the surface oxides of the titanium alloy are cross-linked through rare earth coordination bonds to form a carbon nanotube network constructed by coordination bonds.

[0049] The apparent contact angles of deionized water and diiodomethane were tested on the surface of the TA2 titanium alloy plate before and after the modification in step (2). The results are as follows: Figure 3 As shown, from Figure 3 It can be seen that the apparent contact angle of SPC0.5-Ti after modification is significantly lower than that of S-Ti. At the same time, the surface energy of TA2 titanium alloy plate is calculated based on the apparent contact angle results. The results are as follows: Figure 4 The total surface energy, polar component of surface energy and non-polar component of surface energy of the modified SPC0.5-Ti are significantly increased compared with those of S-Ti, which indicates that the surface wetting properties of the modified TA2 titanium alloy plate are significantly improved, which is beneficial to the wetting behavior of the resin on the titanium plate surface.

[0050] The difference between this comparative example and the embodiment is that S2 is omitted, and the specific process is as follows:

[0051] (1) First, the surface of the TA2 titanium alloy plate was sandblasted with 60-mesh corundum sand at a blasting distance of 120 mm, a blasting pressure of 0.2 MPa, and a blasting time of 20 s. It was then ultrasonically cleaned in a 30 ℃ acetone solution for 30 min and dried in an 80 ℃ oven for 8 h. The resulting product was recorded as S-Ti.

[0052] (2) First, the TA2 titanium alloy plate and prepreg CFRTP (Jiangsu Junhua Special Engineering Plastics Products Co., Ltd.) after sandblasting in step (1) were prepared according to [M / 0 3 / M / 0 3 / M] unidirectional ply structure, wherein the [M / 0 3 / M / 0 3 / M] where M stands for metal, 0 3 The laying angle of the representative prepreg is 0°, the number of layers is 3, and a layer of PEEK film is laminated between each layer of TA2 titanium alloy plate and prepreg CFRTP;

[0053] Subsequently, hot pressing is carried out, and the hot pressing process is as follows: starting from room temperature, heating to 390°C at a rate of 10°C / min and then keeping warm for 30 min, then cooling to 300°C and keeping warm for 30 min, and then continuing to cool to 170°C and keeping warm for 30 min, and finally cooling to room temperature. The cooling rate of the cooling process is always maintained at 1°C / min, and the pressure is maintained at 5 MPa throughout the process to obtain a fiber metal laminate.

[0054] According to ASTM D1002, a single lap joint shear test was performed on the TA2 titanium alloy plate and the PEEK resin in the fiber metal laminates prepared in Example 1 of the present invention and the comparative example to evaluate the interface bonding strength. The test results are as follows: Figure 5 As shown, from Figure 5 It can be seen that the interface shear strength of the fiber metal laminate obtained in Example 1 of the present invention is as high as 39.4 MPa. It can be seen that compared with the fiber metal laminate of the comparative example, the interface shear strength of the fiber metal laminate obtained in Example 1 of the present invention is increased by 205.4%.

[0055] The mechanical properties of the fiber metal laminates prepared in Example 1 of the present invention and the comparative example were tested, and the bending strength and interlaminar shear strength were tested according to ASTM D7264 and ASTM D2344 standards, respectively. The test results are shown in FIG. Figure 6 As shown, from Figure 6 It can be seen that the bending strength of the fiber metal laminate obtained in Example 1 of the present invention is as high as 1972.0 MPa, and the interlaminar shear strength is as high as 93.7 MPa. Compared with the fiber metal laminate of the comparative example, the bending strength and interlaminar shear strength are increased by 210.0% and 95.2%, respectively.

[0056] The above are only preferred specific embodiments of the present invention, which are all different implementations based on the overall concept of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for modifying the interface of fiber metal laminates by physical-chemical synergy, It is characterized in that The process includes the following: S1: First, the metal surface is sandblasted, then immersed in an ethanol solution of a rare earth metal salt and ultrasonically immersed, and then resin and carbon nanotubes are added and ultrasonically immersed for a period of time; the carbon nanotubes are carboxylated carbon nanotubes; S2: Take out, dry the treated metal, then rinse with ethanol, and dry again to complete the modification.

2. The method according to claim 1, It is characterized in that The concentration of the ethanol solution of the rare earth metal salt in S1 is 0.3-0.8 wt.%, and the rare earth metal salt is selected from chlorides of rare earth elements.

3. The method according to claim 2, It is characterized in that The rare earth element includes Ce, La or Pr.

4. The method according to claim 1, It is characterized in that The resin in S1 is PEI, and the added amount is 0.5-1.0wt.% of the ethanol solution of the rare earth metal salt.

5. The method according to claim 1, It is characterized in that The amount of carboxylated carbon nanotubes added in S1 is 0.1-1.0 wt. % of the ethanol solution of the rare earth metal salt.

6. The method according to claim 1, It is characterized in that The ultrasonic immersion parameters in S1 are: power 80-100 W, frequency 40-50 Hz, and time 15-60 min.

7. The method according to claim 1, It is characterized in that The drying temperature in S2 is 60-80°C and the drying time is 1-6h.

8. A method for preparing a high-performance fiber metal laminate, It is characterized in that Follow these steps: The metal and prepreg CFRTP modified by the method described in any one of claims 1 to 7 are prepared according to [M / 0 3 / M / 0 3 / M] unidirectional ply structure is laid, and a layer of PEEK film is stacked between each layer of metal and prepreg CFRTP, followed by hot pressing to obtain a fiber metal laminate; wherein the [M / 0 3 / M / 0 3 / M] where M stands for metal, 0 3 The laying angle of the representative prepreg is 0° and the number of laying layers is 3.

9. The fiber metal laminate obtained by the method according to claim 8, It is characterized in that Interface shear strength ≥35MPa, bending strength ≥1900MPa, interlaminar shear strength ≥90MPa.

10. Use of the fiber metal laminate according to claim 9, It is characterized in that The fiber metal laminate is used in the marine and aerospace fields.

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