Graphene-aluminum-based composite material preparation method and preparation device

Abstract

The application relates to the field of solid-phase connection, and discloses a preparation method and a preparation device of a graphene aluminum-based composite material, and the preparation device is suitable for the preparation method. The preparation method comprises the following steps: step one, alternately stacking aluminum-based layers and graphene layers, and making the two layers at the two ends in the stacking direction be aluminum-based layers, so as to obtain a stacked blank; step two, applying a preset pressure to the stacked blank along the stacking direction of the aluminum-based layers and the graphene layers, so that the adjacent aluminum-based layers and graphene layers are in close contact; and step three, applying ultrasonic vibration to the stacked blank, and performing friction stir welding on the aluminum-based layers and the graphene layers. Compared with a powder metallurgy method, the graphene aluminum-based composite material prepared by the friction stir welding and the ultrasonic vibration under a certain pressure is more uniform in graphene distribution in the aluminum matrix, and the graphene aluminum-based composite material is better in mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of solid-phase bonding, and in particular to a method and apparatus for preparing graphene-aluminum-based composite materials. Background Technology

[0002] Metal matrix composites possess advantages such as high specific strength, high toughness, good wear resistance, excellent electrical and thermal conductivity, and good designability, making them widely used in aerospace, transportation, and electronics industries. Among them, aluminum matrix composites, due to their lightweight, high strength, corrosion resistance, and wear resistance, have become the most widely used type of metal matrix composite in the aerospace field. However, technological advancements and changes in the service environment of materials have placed higher demands on the performance of aluminum matrix composites. The performance of traditional ceramic particle-reinforced aluminum matrix composites is no longer sufficient to meet these requirements, necessitating the development of high-performance aluminum matrix composites.

[0003] Aluminum-based composites generally consist of an aluminum or aluminum alloy matrix and a reinforcing phase. The type, size, distribution, content of the reinforcing phase, and the interface between the reinforcing phase and the aluminum matrix are the main factors determining the properties of aluminum-based composites. Therefore, the selection of the reinforcing phase is extremely important for the preparation of high-performance aluminum-based composites. In engineering, graphene, with its ultra-low density, ultra-high strength, and good flexibility, is often chosen as the ideal reinforcement for aluminum-based composites. However, graphene is prone to agglomeration, and the bond between graphene and the aluminum matrix is ​​weak. To effectively improve the dispersion of graphene in the aluminum matrix and the interfacial bonding between the two, researchers have developed various preparation methods. Currently, powder metallurgy is mainly used to prepare graphene-aluminum-based composites, but this method still suffers from the problem of poor uniformity of graphene distribution in the aluminum matrix.

[0004] Therefore, how to make graphene more uniformly distributed in an aluminum matrix has become a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the above technical problems, this invention provides a method and apparatus for preparing graphene-aluminum matrix composites that enables graphene to be distributed more uniformly in an aluminum matrix.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a method for preparing graphene-aluminum-based composite materials, comprising the following steps:

[0008] Step 1: Alternately stack aluminum substrate and graphene layer, and make the two layers at both ends of the stacking direction both aluminum substrate, to obtain a stacked blank;

[0009] Step 2: Apply a preset pressure to the laminated blank along the stacking direction of the aluminum substrate and the graphene layer to make adjacent aluminum substrates and graphene layers adhere to each other;

[0010] Step 3: Apply ultrasonic vibration to the laminated blank and perform friction stir welding on the aluminum base layer and the graphene layer.

[0011] The present invention also provides a graphene-aluminum-based composite material preparation apparatus suitable for the aforementioned graphene-aluminum-based composite material preparation method, comprising:

[0012] A pressurizing mechanism for applying the pressure to the laminated blank;

[0013] An ultrasonic vibration mechanism for applying ultrasonic vibration to the laminated blank;

[0014] Friction stir welding mechanism for performing friction stir welding on the stacked blanks.

[0015] Optionally, the ultrasonic vibration mechanism includes an ultrasonic generator, an ultrasonic transducer, and a vibration head connected in sequence.

[0016] Optionally, the graphene-aluminum composite material preparation apparatus further includes a control element and a sensor, wherein the sensor is used to monitor the output frequency of the vibrating head, and both the sensor and the ultrasonic generator are communicatively connected to the control element.

[0017] Optionally, the graphene-aluminum composite material preparation apparatus further includes a driving mechanism, which is connected to both the ultrasonic vibration mechanism and the friction stir welding mechanism to drive the ultrasonic vibration mechanism and the friction stir welding mechanism to move.

[0018] Optionally, the driving mechanism includes a first linear driver and a second linear driver that are perpendicular to each other. The first linear driver is connected to the second linear driver to drive the second linear driver to move. The second linear driver is connected to both the ultrasonic vibration mechanism and the friction stir welding mechanism to drive the ultrasonic vibration mechanism and the friction stir welding mechanism to move. The movement directions of the ultrasonic vibration mechanism and the friction stir welding mechanism are both perpendicular to the movement direction of the second linear driver.

[0019] Optionally, the drive mechanism further includes a support platform;

[0020] The first linear actuator includes two first lead screws and two first motors. The two first motors are respectively connected to the two first lead screws to drive the two first lead screws to rotate. The two first lead screws are respectively arranged on opposite sides of the support platform. Each first lead screw is axially positioned and rotatably connected to the support platform.

[0021] The second linear actuator includes two second lead screws, two second motors, two guide rails, two sliders, and a connecting structure. Both second lead screws are axially positioned and rotatably connected to the two guide rails respectively. The axial direction of the second lead screw is parallel to the length direction of the guide rail, and the axial direction of the second lead screw is perpendicular to the axial direction of the first lead screw. The two second motors are respectively connected to the two second lead screws to drive their rotation. The two sliders are slidably connected to the two guide rails respectively. The two sliders are respectively sleeved on the two second lead screws and threadedly connected to them. The two sliders are connected through the connecting structure. The ultrasonic vibration mechanism and the friction stir welding mechanism are both connected to the connecting structure.

[0022] The two first lead screws pass through the two guide rails respectively, and the two guide rails are threadedly connected to the two first lead screws respectively. Each of the two guide rails is provided with a guide block. The two guide grooves are provided on opposite sides of the support platform. The two guide blocks are slidably connected to the two guide grooves respectively. The length direction of the guide groove is parallel to the axial direction of the first lead screw.

[0023] Optionally, the graphene-aluminum composite material preparation device further includes a first positioning fixture, a second positioning fixture, a first connecting plate, a second connecting plate, an intermediate connecting member, bolts, and nuts;

[0024] The ultrasonic vibration mechanism is positioned and clamped between the first positioning fixture and the second positioning fixture, and the first positioning fixture and the second positioning fixture are detachably connected.

[0025] The first connecting plate and the second connecting plate are parallel and opposite to each other. The first connecting plate is connected to the second linear actuator. The second connecting plate is connected to the first positioning fixture or the second positioning fixture through the intermediate connecting member. The second connecting plate is provided with a through groove. One end of the bolt passes through the through groove and the second connecting plate in sequence and is fastened by the nut. The bolt is slidably connected to the through groove.

[0026] Optionally, the two opposite sidewalls of the through groove are both serrated structures.

[0027] Optionally, the pressurizing mechanism includes two clamping plates and two third linear actuators. The two third linear actuators are respectively connected to the two clamping plates, and the two third linear actuators are respectively used to drive the two clamping plates away from or towards each other along the stacking direction of the aluminum base layer and the graphene layer.

[0028] The present invention achieves the following technical effects compared to the prior art:

[0029] The graphene-aluminum matrix composite material preparation method provided by this invention utilizes friction stir welding combined with ultrasonic vibration to prepare graphene-aluminum matrix composite materials. Compared with the preparation of graphene-aluminum matrix composite materials by powder metallurgy, the preparation method of this invention not only overcomes the problem of undesirable interfacial reactions between graphene and aluminum matrix in powder metallurgy, thus improving the mechanical properties of graphene-aluminum matrix composite materials, but also refines the grains through temperature effects, vibration effects, and intense plastic deformation. Furthermore, ultrasonic vibration can further disperse graphene, resulting in better uniformity of graphene reinforcing phase distribution in the aluminum matrix, optimizing the microstructure and properties, and improving the strength and toughness of graphene-aluminum matrix composite materials. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of the stacked blank provided in an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram illustrating the arrangement of the stacked blank clamping plate provided in an embodiment of the present invention;

[0033] Figure 3 This is a perspective view of the graphene-aluminum-based composite material preparation apparatus provided in the embodiments of the present invention;

[0034] Figure 4 This is a front view of the graphene-aluminum-based composite material preparation apparatus provided in an embodiment of the present invention;

[0035] Figure 5 This is a side view of the graphene-aluminum composite material preparation apparatus provided in an embodiment of the present invention.

[0036] Figures 1-5Explanation of reference numerals in the attached drawings: 1. Stacked blank; 101. Aluminum base layer; 102. Graphene layer; 2. Bolt; 3. Clamping plate; 4. First connecting plate; 5. Ultrasonic generator; 6. Ultrasonic transducer; 7. Sensor; 8. Slider; 9. Second connecting plate; 901. Through groove; 10. Guide rail; 11. Second lead screw; 12. First positioning fixture; 13. Second motor; 14. Friction stir welding mechanism; 1401. Stirring needle; 15. Second positioning fixture; 16. Intermediate connecting piece; 17. Vibrating head; 18. Connecting structure; 19. Support platform; 1901. Guide groove; 20. First lead screw; 21. First motor. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The purpose of this invention is to provide a method and apparatus for preparing graphene-aluminum matrix composites that enables graphene to be distributed more uniformly in an aluminum matrix.

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] refer to Figures 1-5 As shown, the method for preparing graphene-aluminum-based composite materials provided in this embodiment of the invention includes the following steps:

[0041] Step 1, as follows Figure 1 As shown, aluminum substrate 101 and graphene layer 102 are alternately stacked, and the two layers at both ends of the stacking direction are aluminum substrate 101 to obtain stacked blank 1.

[0042] Step 2: Apply a preset pressure to the laminated blank 1 along the stacking direction of the aluminum base layer 101 and the graphene layer 102 so that the adjacent aluminum base layer 101 and graphene layer 102 are in contact.

[0043] Step three involves applying ultrasonic vibration to the laminated blank 1 and performing friction stir welding on the aluminum base layer 101 and the graphene layer 102. The purpose of friction stir welding is to disperse the graphene in the graphene layer 102 within the aluminum base layer 101 and to connect the layers of the laminated blank 1 into a unified whole. How this is achieved is well-known to those skilled in the art and will not be elaborated upon here. Furthermore, the preset pressure applied in step two is not removed during friction stir welding; the preset pressure remains applied to the laminated blank 1 throughout the entire welding process.

[0044] The graphene-aluminum matrix composite material preparation method provided in this embodiment of the invention utilizes friction stir welding combined with ultrasonic vibration to prepare the graphene-aluminum matrix composite material. Compared with the graphene-aluminum matrix composite material preparation method using powder metallurgy, the graphene-aluminum matrix composite material preparation method provided by this invention not only overcomes the problem of undesirable interfacial reactions between graphene and aluminum matrix in powder metallurgy, thus improving the mechanical properties of the graphene-aluminum matrix composite material, but also refines the grains through temperature effect, vibration effect, and intense plastic deformation, resulting in better uniformity of graphene reinforcing phase distribution in the aluminum matrix, optimizing the microstructure and properties, and improving the strength and toughness of the graphene-aluminum matrix composite material.

[0045] It should be noted that the aluminum base layer 101 is made of an aluminum matrix, such as aluminum alloy or aluminum, and the graphene layer 102 is made of graphene material. The number of aluminum base layer 101 and graphene layer 102 depends on actual needs, and the thickness of aluminum base layer 101 and graphene layer 102 is related to the ratio of graphene to aluminum matrix in the graphene-aluminum matrix composite material. Different ratios require different amounts of graphene and aluminum matrix.

[0046] Furthermore, the frequency of ultrasonic vibration and the magnitude of the preset pressure applied to the laminated blank 1 during processing are optimized according to the thickness of the laminated blank 1. The specific optimization methods are common knowledge in the art and are not the focus of this invention, so they will not be elaborated here. The graphene-aluminum-based composite material preparation method provided in this embodiment of the invention is rationally designed, simple in process, and stable in control, effectively solving the limitations existing in the preparation process of graphene-aluminum-based composite materials, and providing an effective method for achieving the production goal of integrated material preparation and performance improvement.

[0047] refer to Figures 1-5 As shown in the figure, this embodiment of the invention also provides a graphene-aluminum-based composite material preparation apparatus suitable for the preparation method of graphene-aluminum-based composite materials, comprising:

[0048] A pressurizing mechanism for applying a preset pressure to the laminated blank 1;

[0049] An ultrasonic vibration mechanism for applying ultrasonic vibration to the laminated blank 1;

[0050] Friction stir welding mechanism 14 for performing friction stir welding on stacked blanks 1.

[0051] As an alternative implementation method, such as Figure 3 As shown, the ultrasonic vibration mechanism includes an ultrasonic generator 5, an ultrasonic transducer 6, and a vibrating head 17 connected in sequence. Furthermore, the graphene-aluminum-based composite material preparation apparatus also includes a control element and a sensor 7. The sensor 7 is used to monitor the output frequency of the vibrating head 17. The sensor 7 is communicatively connected to the control element to transmit the monitored output frequency information of the vibrating head 17 to the control element. The control element is communicatively connected to the ultrasonic generator 5 to control the operation of the ultrasonic generator 5 according to the output frequency information of the vibrating head 17 monitored by the sensor 7.

[0052] In practical use, the ultrasonic generator 5 generates an AC signal with ultrasonic frequency, which is converted into mechanical vibration by the ultrasonic transducer 6. After being monitored and adjusted by the sensor 7, the mechanical vibration is transmitted to the stacked blank 1 by the vibrating head 17.

[0053] The frequency adjustment range of the ultrasonic generator 5 is, for example, 20kHz-100kHz, and the control element is, for example, a controller, more specifically, a PLC controller.

[0054] As an optional implementation, the graphene aluminum-based composite material preparation apparatus further includes a drive mechanism, which is connected to both the ultrasonic vibration mechanism and the friction stir welding mechanism 14 to drive the ultrasonic vibration mechanism and the friction stir welding mechanism 14 to move, for example, to rotate and / or move in a linear direction.

[0055] Specifically, in this embodiment, such as Figure 3 As shown, the driving mechanism includes a first linear driver and a second linear driver that are perpendicular to each other. The first linear driver is connected to the second linear driver to drive the second linear driver to move. The second linear driver is connected to both the ultrasonic vibration mechanism and the friction stir welding mechanism 14 to drive the ultrasonic vibration mechanism and the friction stir welding mechanism 14 to move. The movement directions of the ultrasonic vibration mechanism and the friction stir welding mechanism 14 are both perpendicular to the movement direction of the second linear driver.

[0056] More specifically, such as Figure 3 As shown, the driving mechanism provided in this embodiment also includes a support platform 19. The first linear driver includes two first lead screws 20 and two first motors 21. The two first motors 21 are respectively connected to the two first lead screws 20 to drive the two first lead screws 20 to rotate. The two first lead screws 20 are respectively arranged on opposite sides of the support platform 19. Each first lead screw 20 is axially positioned and rotatably connected to the support platform 19.

[0057] like Figure 3 As shown, the second linear actuator includes two second lead screws 11, two second motors 13, two guide rails 10, two sliders 8, and a connecting structure 18, which may be, for example, a connecting plate. Both second lead screws 11 are axially positioned and rotatably connected to the two guide rails 10. The axial direction of the second lead screw 11 is parallel to the length direction of the guide rail 10, and the axis of the second lead screw 11 is perpendicular to the axis of the first lead screw 20. The two second motors 13 are connected to the two second lead screws 11 respectively to drive them to rotate. The two sliders 8 are slidably connected to the two guide rails 10, respectively, and are respectively sleeved on the two second lead screws 11 and threadedly connected to them. The two sliders 8 are connected through the connecting structure 18. The ultrasonic vibration mechanism and the friction stir welding mechanism 14 are both connected to the connecting structure 18. In actual use, the second motor 13 rotates, and the slider 8 moves along the axis of the second lead screw 11, thereby driving the connecting structure 18 and the ultrasonic vibration mechanism and friction stir welding mechanism 14 set on the connecting structure 18 to move synchronously, so as to adjust the position of the ultrasonic vibration mechanism and friction stir welding mechanism 14.

[0058] like Figure 3 As shown, two first lead screws 20 pass through two guide rails 10 respectively, and the two guide rails 10 are threadedly connected to the two first lead screws 20. Guide blocks are provided on both guide rails 10. Two guide grooves 1901 are provided on opposite sides of the support platform 19. The two guide blocks are slidably connected to the two guide grooves 1901. The length direction of the guide grooves 1901 is parallel to the axial direction of the first lead screws 20. In actual use, the first motor 21 rotates, driving the first lead screws 20 to rotate synchronously. As the first lead screws 20 rotate, the guide rails 10 move along the axial direction of the first lead screws 20, thereby driving the ultrasonic vibration mechanism and the friction stir welding mechanism 14 to move synchronously, realizing the adjustment of the positions of the ultrasonic vibration mechanism and the friction stir welding mechanism 14.

[0059] It should be noted that axial positioning means that the first lead screw 20 cannot move along its axial direction, and the first linear actuator and the second linear actuator can adjust the positions of the ultrasonic vibration mechanism and the friction stir welding mechanism 14 in two mutually perpendicular directions. Specifically, in this embodiment, the above two directions are perpendicular to the stacking direction of the stacked blank 1, and the ultrasonic vibration mechanism is set in front of the friction stir welding mechanism 14 so as to apply ultrasonic vibration to the stacked blank 1 and then perform friction stir welding on the aluminum base layer 101 and the graphene layer 102. In the specific preparation process, the stacked blank 1 is supported on the support platform 19 and is located between the support platform 19 and the vibration head 17 of the ultrasonic vibration mechanism and between the support platform 19 and the stirring needle 1401 of the friction stir welding mechanism 14. The specific structure of the friction stir welding mechanism 14 belongs to the prior art and will not be described in detail here.

[0060] Furthermore, such as Figures 4-5 As shown, the graphene-aluminum composite material preparation device also includes a first positioning fixture 12, a second positioning fixture 15, a first connecting plate 4, a second connecting plate 9, an intermediate connecting piece 16, a bolt 2, and a nut.

[0061] The ultrasonic vibration mechanism is positioned and clamped between the first positioning clamp 12 and the second positioning clamp 15, and the first positioning clamp 12 and the second positioning clamp 15 are detachably connected. Specifically, in this embodiment, the first positioning clamp 12 and the second positioning clamp 15 are used to position and clamp the vibration head 17 of the ultrasonic vibration mechanism, the sensor 7 is disposed on the vibration head 17, and the shapes of the first positioning clamp 12 and the second positioning clamp 15 match the shape of the outer side wall of the vibration head 17.

[0062] The first connecting plate 4 and the second connecting plate 9 are arranged parallel to each other and opposite to each other. The first connecting plate 4 is connected to the second linear actuator, and the second connecting plate 9 is connected to the first positioning fixture 12 or the second positioning fixture 15 through the intermediate connecting piece 16. The second connecting plate 9 is provided with a through groove 901. One end of the bolt 2 passes through the through groove 901 and the second connecting plate 9 in sequence and is fastened with a nut. The bolt 2 is slidably connected to the through groove 901. With this arrangement, the relative position of the first connecting plate 4 and the second connecting plate 9 can be adjusted by adjusting the position of the bolt 2 in the through groove 901, thereby realizing the fine adjustment of the installation position of the ultrasonic vibration mechanism and the friction stir welding mechanism 14.

[0063] Furthermore, to prevent the first connecting plate 4 and the second connecting plate 9 from moving relative to each other due to ultrasonic influence, the two opposite sidewalls of the through groove are both serrated structures.

[0064] As an alternative implementation method, such as Figure 2 As shown, the pressurizing mechanism includes two clamping plates 3 and two third linear actuators. The two third linear actuators are respectively connected to the two clamping plates 3. The two third linear actuators are used to drive the two clamping plates 3 to move away from or towards each other along the stacking direction of the aluminum base layer 101 and the graphene layer 102. The third linear actuators are, for example, hydraulic cylinders.

[0065] In practical use, by adjusting the distance between the two clamping plates 3, the interlayer pressure of the stacked blank 1 can be adjusted. Under the action of thermo-mechanical-acoustic multi-field coupling, the stacked blank 1 can obtain a graphene aluminum-based composite material with excellent structure and properties.

[0066] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for preparing a graphene-aluminum-based composite material, characterized in that, Includes the following steps: Step 1: Alternately stack aluminum substrate and graphene layer, with the two layers at both ends of the stacking direction being the aluminum substrate, to obtain a stacked blank, wherein the graphene layer is made of graphene material; Step 2: Apply a preset pressure to the laminated blank along the stacking direction of the aluminum base layer and the graphene layer to make adjacent aluminum base layers and graphene layers adhere to each other. The preset pressure is applied by a pressurizing mechanism, which includes two clamping plates and two third linear actuators. The two third linear actuators are respectively connected to the two clamping plates. The two third linear actuators are used to drive the two clamping plates away from each other or closer to each other along the stacking direction of the aluminum base layer and the graphene layer. The size of the clamping plates is the same as the size of the laminated blank, and the clamping plates can cover the surface of the laminated blank. Step 3: Apply ultrasonic vibration to the laminated blank and perform friction stir welding on the aluminum base layer and the graphene layer. Through temperature effect, vibration effect and plastic deformation, the graphene in the graphene layer is dispersed in the aluminum base layer, and the layers of the laminated blank are connected to each other to form a whole. The pre-pressure is always present during the friction stir welding process.

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