NiTi continuous wire / aluminum-based composite material and preparation method and application thereof

Abstract

The invention provides a NiTi continuous wire / aluminum-based composite material and a preparation method and application thereof, and belongs to the technical field of aluminum-based composite materials. The invention provides a preparation method of a NiTi continuous wire / aluminum-based composite material, which comprises the following steps of: preparing an aluminum matrix by adopting a stirring friction additive to obtain a deposition layer; the deposition layer is subjected to grooving, then grooves are filled with NiTi continuous wires, then the grooves are filled with aluminum-based materials through friction stir additive materials, and the NiTi continuous wire / aluminum-based composite material is obtained. According to the preparation method, the NiTi continuous wires are filled in the aluminum matrix, and then the aluminum-based material is deposited through friction stir additive deposition, so that the composite material with relatively high mechanical properties can be obtained through the shape memory effect of the NiTi continuous wires, and meanwhile, the composite materials with different properties can be obtained by changing the phase composition of the NiTi shape memory alloy.

Description

Technical Field

[0001] This invention belongs to the field of aluminum-based composite material technology, specifically relating to a NiTi continuous filament / aluminum-based composite material, its preparation method, and its application. Background Technology

[0002] Nickel-titanium continuous wire (NiTi continuous wire) reinforced aluminum matrix composites possess advantages such as high strength, low density, intelligence, and variable stiffness, showing broad application prospects in advanced electronic intelligent switches, high-end automotive intelligent tail wings, intelligent aircraft skins, and intelligent engine exhaust nozzles and lips. Currently, the method for producing NiTi continuous wire reinforced aluminum matrix composites is extrusion casting. This method has certain drawbacks, such as high casting temperatures leading to excessive reactions between the NiTi continuous wire and the aluminum matrix, forming a large number of hard and brittle reaction layers. The resulting NiTi continuous wire reinforced aluminum matrix composites exhibit microcracks at the interface, resulting in poor mechanical properties and consequently slow intelligent action response speeds. Furthermore, traditional extrusion casting requires pre-fabricating molds based on the structure, hindering the rapid and flexible customization of intelligent structures. Therefore, how to improve NiTi continuous wire / aluminum matrix composites to increase the interfacial bonding between the NiTi continuous wire and the aluminum matrix has become a pressing technical challenge in this field. Summary of the Invention

[0003] The purpose of this invention is to provide a NiTi continuous filament / aluminum matrix composite material, its preparation method, and its applications. The preparation method provided by this invention can increase the interfacial bonding between the NiTi continuous filament and the aluminum matrix, and the arrangement and content of the NiTi continuous filament are adjustable, with a simple process.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing NiTi continuous filament / aluminum-based composite materials, comprising the following steps: (1) An aluminum substrate was prepared by friction stir additive manufacturing to obtain a deposited layer; (2) The deposited layer obtained in step (1) is grooved, and then NiTi continuous filament is filled in the groove. Then, aluminum-based material is filled in the groove by friction stirring additive manufacturing to obtain NiTi continuous filament / aluminum-based composite material.

[0005] Preferably, the thickness of the deposited layer in step (1) is 1~4 mm.

[0006] Preferably, the depth of the groove in step (2) is 0.5~1.5mm.

[0007] Preferably, the diameter of the NiTi continuous wire in step (2) is 0.5~1.5mm.

[0008] Preferably, in step (2), the NiTi continuous filament is pretreated before use, and the pretreatment includes grinding, cutting, acid treatment, cleaning and drying in sequence.

[0009] Preferably, step (2) further includes filling the groove with powdered zinc-aluminum based brazing filler metal after filling the groove with NiTi continuous wire.

[0010] Preferably, the process parameters for friction stir additive manufacturing in step (2) include: rotational speed of 1500~1700rpm, travel speed of 110~130mm / min, and wire feeding speed of 1~3m / min.

[0011] Preferably, in step (2), after the aluminum-based material is filled in the tank by friction stirring additive manufacturing, an aging heat treatment is also performed; the holding temperature of the aging heat treatment is 100~150℃, and the holding time of the aging heat treatment is 10~16h.

[0012] The present invention also provides a NiTi continuous filament / aluminum-based composite material prepared by the preparation method described in the above technical solution.

[0013] This invention also provides the application of the NiTi continuous filament / aluminum-based composite material described above in advanced electronic intelligent switches, automotive intelligent rear wings, intelligent skins, intelligent engine exhaust nozzles, and intelligent engine exhaust lips.

[0014] This invention provides a method for preparing a NiTi continuous filament / aluminum-based composite material, comprising the following steps: preparing an aluminum matrix using friction stir additive manufacturing to obtain a deposited layer; slotting the deposited layer; filling the slots with NiTi continuous filaments; and then filling the slots with aluminum-based material using friction stir additive manufacturing to obtain the NiTi continuous filament / aluminum-based composite material. This invention fills the interior of the aluminum matrix with NiTi continuous filaments and then deposits the aluminum-based material using friction stir additive manufacturing, which can improve the interfacial bonding strength between the aluminum matrix and the NiTi continuous filaments. Results from the embodiments show that the NiTi continuous filament / aluminum-based composite material prepared by the method provided by this invention has a bonding layer thickness of 3.29~16μm and a tensile strength of 217.1~350.3MPa. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention with grooves in the deposition layer; Figure 2 This is a schematic diagram of the additive manufacturing process after filling the groove with continuous NiTi filaments according to the present invention; Figure 3 This is a macroscopic cross-sectional view of the NiTi continuous filament / aluminum matrix composite material prepared in Example 1; Figure 4The microstructure of the NiTi continuous filament / aluminum matrix composite material prepared in Example 1 is shown in the diagram. Figure 5 The thickness curve of the bonding layer of the NiTi continuous filament / aluminum matrix composite material prepared in Example 1 is shown. Figure 6 The tensile strength of the aluminum matrix and the NiTi continuous filament / aluminum matrix composite material in Example 1; Figure 7 This is a cross-sectional view of the NiTi continuous filament / aluminum matrix composite material prepared in Comparative Example 1; Figure 8 This is a cross-sectional view of the NiTi continuous filament / aluminum matrix composite material prepared in Example 4. Detailed Implementation

[0016] This invention provides a method for preparing NiTi continuous filament / aluminum-based composite materials, comprising the following steps: (1) An aluminum substrate was prepared by friction stir additive manufacturing to obtain a deposited layer; (2) The deposited layer obtained in step (1) is grooved, and then NiTi continuous filament is filled in the groove. Then, aluminum-based material is filled in the groove by friction stirring additive manufacturing to obtain NiTi continuous filament / aluminum-based composite material.

[0017] The present invention does not have any special limitations on the source of the raw materials, and commercially available products known to those skilled in the art can be used.

[0018] This invention uses friction stir additive manufacturing to prepare an aluminum substrate and obtain a deposited layer.

[0019] The present invention does not impose any special limitations on the specific operation of the friction stir additive manufacturing process; any operation known to those skilled in the art can be used.

[0020] The present invention does not impose any special limitation on the specific type of aluminum substrate; it can be selected according to actual needs.

[0021] In one embodiment, the aluminum substrate can be a 4043 aluminum substrate or a 7075 aluminum substrate.

[0022] In this invention, the thickness of the deposited layer is preferably 1 to 4 mm. As one embodiment, the thickness of the deposited layer can be 2 mm, 2.5 mm, or 3 mm.

[0023] After obtaining the deposited layer, the present invention grooves the deposited layer, fills the groove with NiTi continuous filament, and then fills the groove with aluminum-based material using friction stirring additive manufacturing to obtain NiTi continuous filament / aluminum-based composite material.

[0024] In this invention, the deposited layer is preferably milled before trenching. The milling operation is not particularly limited, as long as the surface of the deposited layer is smooth.

[0025] The present invention does not have a special limitation on the position of the slot, which can be adjusted according to actual needs.

[0026] In this invention, the depth of the slot (D) 槽深 The depth is preferably 0.5~1.5mm. In one embodiment, the depth of the groove can be 0.8mm, 1.1mm, or 1.2mm.

[0027] The present invention does not impose any special limitations on the grooving operation, as long as the specified depth is reached.

[0028] The present invention does not have a special limitation on the width of the slot; it can be adjusted according to the width of the actual NiTi continuous wire.

[0029] The present invention does not have a special limitation on the number of slots, which can be adjusted according to actual needs.

[0030] In this invention, the diameter of the NiTi continuous filament is preferably 0.5~1.5 mm. As one embodiment, the diameter of the NiTi continuous filament can be 1.0 mm or 1.2 mm. Limiting the diameter of the NiTi continuous filament to the above range ensures that only part of the groove is filled, followed by the deposition of the aluminum-based material, which further improves the interfacial bonding strength of the composite material.

[0031] In this invention, the NiTi continuous filament is preferably pretreated before use; the pretreatment preferably includes grinding, cutting, acid treatment, cleaning and drying in sequence.

[0032] The present invention does not have any special limitations on the polishing operation, as long as the surface protrusions are removed.

[0033] The present invention does not impose any special limitations on the cutting operation; it is sufficient to cut to the required length.

[0034] The present invention does not have any special limitations on the operation of the acid treatment, as long as the oxide film on the surface is removed.

[0035] The present invention does not impose any special limitations on the cleaning operation, as long as the cleaning is thorough.

[0036] In one embodiment, the cleaning agent used for cleaning can be a mixed aqueous solution of HNO3 and HF; the cleaning can be ultrasonic cleaning; and the cleaning time can be 10-30 minutes.

[0037] In this invention, the drying temperature is preferably 40~90℃; the drying time is preferably 10~20min.

[0038] After drying, the product obtained by drying is preferably cooled; the cooling is preferably air cooling. The present invention does not have any particular limitations on the air cooling operation, and any operation well known to those skilled in the art can be used.

[0039] The present invention does not impose any special limitations on the operation of filling the groove with NiTi continuous wire; any operation known to those skilled in the art can be used.

[0040] In this invention, after filling the groove with NiTi continuous wire, it is preferable to further fill the groove with powdered zinc-aluminum-based brazing filler metal; the powdered zinc-aluminum-based brazing filler metal preferably fills the groove completely. This invention does not have a specific limitation on the amount of zinc-aluminum-based brazing filler metal used, as long as the gaps in the groove are filled. In this invention, the zinc-aluminum-based brazing filler metal can fill the gaps in the groove of the NiTi continuous wire, and it melts during friction stir additive manufacturing. The melted zinc-aluminum-based brazing filler metal can increase the interfacial bonding performance between the NiTi continuous wire and the aluminum substrate.

[0041] In this invention, the aluminum-based material is preferably the same as the aforementioned aluminum matrix, which will not be described again here.

[0042] In this invention, the preferred process parameters for the friction stir additive manufacturing process include: a rotational speed of 1500~1700 rpm, a travel speed of 110~130 mm / min, and a wire feeding speed of 1~3 m / min. As one embodiment, the rotational speed can be 1600 rpm, the travel speed can be 120 mm / min, and the wire feeding speed can be 2 m / min.

[0043] In this invention, the downward pressure distance of the stirring pin during friction stir additive manufacturing is preferably 0.5~1mm; the NiTi continuous filament is preferably located below the stirring pin. This invention embeds the NiTi continuous filament below the stirring pin, ensuring that the embedded NiTi continuous filament retains its functional integrity during the additive manufacturing process and will not break, knot, or even violently shatter due to the stirring action.

[0044] The present invention does not impose a specific limitation on the length of the stirring pin; it can be adjusted according to actual needs. As one embodiment, the length of the stirring pin can be 2 mm.

[0045] In this invention, when the thickness of the NiTi continuous filament / aluminum-based composite material is higher than the thickness of the deposited layer, it is preferable to repeat the aforementioned operation, continue to use friction stir additive manufacturing to prepare the deposited layer, then groove the deposited layer, then fill the groove with NiTi continuous filament, and then use friction stir additive manufacturing to fill the groove with aluminum-based material until the desired thickness is achieved.

[0046] In this invention, after the aluminum-based material is filled into the tank using friction stir additive manufacturing, it preferably includes aging heat treatment; the holding temperature of the aging heat treatment is preferably 100~150℃; and the holding time of the aging heat treatment is preferably 10~16h. By limiting the process parameters of the aging heat treatment within the above range, this invention can further improve the mechanical properties of the composite material.

[0047] As one implementation, the holding temperature of the aging heat treatment can be 110℃, 120℃, 130℃ or 140℃; the holding time of the aging heat treatment can be 11h, 12h, 13h, 14h or 15h.

[0048] The schematic diagram of the trenching structure in this invention is shown below. Figure 1 As shown. From Figure 1 It can be seen that the NiTi continuous wire only fills a portion of the groove.

[0049] A schematic diagram of the present invention, in which NiTi continuous wires are filled in the groove, is shown below. Figure 2 As shown. From Figure 2 As can be seen, the stirring needle is positioned above the NiTi continuous wire.

[0050] This invention fills the interior of the deposition layer with NiTi continuous filaments and then uses friction stir additive deposition to deposit aluminum-based materials, which can improve the interfacial bonding strength between the aluminum substrate and the NiTi continuous filaments.

[0051] This invention addresses the problems of long processing cycles, complex processes, and poor quality in traditional NiTi composite materials. It utilizes friction stir solid-state additive manufacturing to prepare NiTi continuous filament / aluminum matrix composites, solving the issues of maintaining the integrity of NiTi continuous filament functions, freely controlling filament arrangement and content, and regulating interfacial reactions and bonding in composite materials. This effectively improves upon the shortcomings of traditional NiTi continuous filament aluminum matrix composites, such as complex processes and long processing cycles. It can be used in structural components requiring high specific strength and impact resistance, such as wing skins, landing gear, and connectors.

[0052] The present invention also provides a NiTi continuous filament / aluminum-based composite material prepared by the preparation method described in the above technical solution.

[0053] This invention also provides the application of the NiTi continuous filament / aluminum-based composite material described above in advanced electronic intelligent switches, automotive intelligent rear wings, intelligent skins, intelligent engine exhaust nozzles, and intelligent engine exhaust lips.

[0054] The present invention does not impose any special limitations on the operation of the NiTi continuous filament / aluminum matrix composite material in advanced electronic intelligent switches, automotive intelligent rear wings, intelligent skins, intelligent engine exhaust nozzles and intelligent engine exhaust lips; any application operations known to those skilled in the art can be used.

[0055] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0056] Example 1 A method for preparing a NiTi continuous filament / aluminum-based composite material is as follows: After installing the additive manufacturing fixture and debugging the additive manufacturing equipment, 4043 aluminum alloy wire is used to continuously add multiple layers on the substrate until the thickness of the deposited layer reaches 4mm, thus obtaining the deposited layer. The surface of the NiTi continuous wire was polished with silicon carbide wet sandpaper to remove surface protrusions. The polished NiTi continuous wire was then cut into 100mm long wires. The NiTi continuous wires were then soaked in a mixed aqueous solution of HNO3 and HF (volume ratio of HNO3, HF and H2O 3:1:6) until the oxide film on the surface of the NiTi continuous wires was etched away. The NiTi continuous wires were then ultrasonically cleaned with anhydrous ethanol for 25 minutes. Finally, the NiTi continuous wires were taken out and placed in an oven at 90℃ for 12 minutes. After that, they were air-cooled to obtain NiTi continuous wires with a diameter of 1.2mm. The deposited layer was milled flat using a milling cutter, and then a groove was cut with a groove depth of 1.2 mm. NiTi continuous wire was then filled into the groove, and 4043 aluminum alloy was filled into the groove using friction stir additive manufacturing to obtain NiTi continuous wire / aluminum-based composite material. The length of the stirring pin was 2 mm, the downward pressing distance of the stirring pin during the additive manufacturing process was 0.7 mm, and the process parameters of friction stir additive manufacturing were: rotation speed 1600 rpm, travel speed 120 mm / min, and wire feed speed 2 m / min.

[0057] Macroscopic image of the NiTi continuous filament / aluminum matrix composite material prepared in Example 1 is shown below. Figure 3 As shown.

[0058] from Figure 3It can be seen that the NiTi continuous wire maintains a circular cross-section during the manufacturing process.

[0059] The magnified view of the interface of the NiTi continuous filament / aluminum matrix composite material prepared in Example 1 is shown below. Figure 4 As shown.

[0060] from Figure 4 As can be seen, even when the interface is zoomed in, it is still clear that the interface is tightly integrated, with no gaps.

[0061] The thickness curve of the bonding layer of the NiTi continuous filament / aluminum matrix composite material prepared in Example 1 is shown below. Figure 5 As shown.

[0062] from Figure 5 It can be seen that the thickness of the bonding layer is 3.29 μm.

[0063] Tensile properties were tested on the aluminum matrix and the NiTi continuous wire / aluminum matrix composite material (i.e., nickel-titanium wire aluminum matrix composite) in Example 1. The tensile strength curves are shown below. Figure 6 As shown.

[0064] from Figure 6 It can be seen that the tensile strength of the NiTi continuous filament / aluminum matrix composite is 217.1 MPa, while the tensile strength of the aluminum matrix is ​​149.7 MPa, representing an increase of 45.02%.

[0065] Example 2 A method for preparing a NiTi continuous filament / aluminum-based composite material is as follows: After installing the additive manufacturing fixture and debugging the additive manufacturing equipment, 7075 aluminum alloy wire is used to continuously add multiple layers on the substrate until the thickness of the deposited layer reaches 3mm, thus obtaining the deposited layer. The surface of the NiTi continuous wire was polished with silicon carbide wet sandpaper to remove surface protrusions. The polished NiTi continuous wire was then cut into short wires with a length of 100 mm. The NiTi continuous wire was then soaked in a mixed aqueous solution of HNO3 and HF (the volume ratio of HNO3, HF and H2O was 3:1:6) until the oxide film on the surface of the NiTi continuous wire was etched away. Then, the NiTi continuous wire was ultrasonically cleaned with anhydrous ethanol for 15 min. Finally, the NiTi continuous wire was taken out and placed in an oven at 90℃ for 12 min. After that, it was taken out and air-cooled to obtain a NiTi continuous wire with a diameter of 1.0 mm. The deposited layer was milled flat using a milling cutter, and then a groove was cut with a groove depth of 1.1 mm. NiTi continuous wire was then filled into the groove, and powdered ZnAl5 zinc-aluminum-based brazing filler metal was then used to fill the gaps in the groove until it was flush with the deposited layer. Finally, 7075 aluminum alloy was used to fill the groove using friction stir additive manufacturing to obtain an intermediate body. The length of the stirring pin was 2 mm, the downward pressing distance of the stirring pin during the additive manufacturing process was 1 mm, and the process parameters of friction stir additive manufacturing were: rotation speed 1600 rpm, travel speed 120 mm / min, and wire feed speed 2 m / min. The intermediate was subjected to aging heat treatment at 120°C for 12 hours to obtain a NiTi continuous filament / aluminum matrix composite material.

[0066] Observing the cross section of the NiTi continuous wire / aluminum matrix composite material prepared in Example 2, it was found that the NiTi continuous wire still maintains a circular cross section, and the interface remains tightly bonded after magnification. The interface layer has a three-layer structure of NiTi continuous wire / zinc-aluminum brazing filler metal / aluminum matrix, and the bonding layer thickness is about 16μm.

[0067] The performance of the NiTi continuous filament / aluminum matrix composite material prepared in Example 2 was tested. The results showed that the tensile strength was 510.72 MPa and the tensile strength of the aluminum matrix was 350.3 MPa, which was an increase of about 45.80%.

[0068] Example 3 A method for preparing a NiTi continuous filament / aluminum-based composite material is as follows: After installing the additive manufacturing fixture and debugging the additive manufacturing equipment, 7075 aluminum alloy wire is used to continuously add multiple layers on the substrate until the thickness of the deposited layer reaches 2.5mm, thus obtaining the deposited layer. The surface of the NiTi continuous wire was polished with silicon carbide wet sandpaper to remove surface protrusions. The polished NiTi continuous wire was then cut into short wires with a length of 100 mm. The NiTi continuous wire was then soaked in a mixed aqueous solution of HNO3 and HF (the volume ratio of HNO3, HF and H2O was 3:1:6) until the oxide film on the surface of the NiTi continuous wire was etched away. Then, the NiTi continuous wire was ultrasonically cleaned with anhydrous ethanol for 25 min. Finally, the NiTi continuous wire was taken out and placed in an oven at 90℃ for 20 min. After that, it was taken out and air-cooled to obtain a NiTi continuous wire with a diameter of 0.5 mm. The deposited layer is milled flat using a milling cutter, then grooved to a depth of 0.5 mm, and then covered with the groove using friction stir additive manufacturing to obtain an intermediate body. The length of the stirring pin is 2 mm, the downward pressing distance of the stirring pin during the additive manufacturing process is 0.5 mm, and the process parameters of friction stir additive manufacturing are: rotation speed 1600 rpm, travel speed 120 mm / min, and wire feed speed 2 m / min. The intermediate was subjected to aging heat treatment at 130°C for 14 hours to obtain a NiTi continuous filament / aluminum matrix composite material.

[0069] Observing the cross section of the NiTi continuous filament / aluminum matrix composite material prepared in Example 3, it was found that the NiTi continuous filament still maintains a circular cross section, and the interface remains tightly bonded after magnification, with a bonding layer thickness of approximately 4.25 μm.

[0070] The performance of the NiTi continuous filament / aluminum matrix composite material prepared in Example 3 was tested. The results showed that the tensile strength was 502.88 MPa and the tensile strength of the aluminum matrix was 276.7 MPa, which was an increase of about 81.74%.

[0071] Comparative Example 1 Based on Example 1, the additive manufacturing process parameters were changed as follows: rotation speed 1200 rpm, travel speed 140 mm / min, wire feeding speed 3.5 m / min, and grooving depth 3 mm, while other conditions remained unchanged.

[0072] Example 4 Based on Example 1, the additive manufacturing process parameters were changed as follows: rotation speed 1500 rpm, travel speed 130 mm / min, wire feeding speed 2.5 m / min, and grooving depth 1.2 mm, while other conditions remained unchanged.

[0073] The cross-sectional view of the NiTi continuous filament / aluminum matrix composite material prepared in Comparative Example 1 is shown below. Figure 7 As shown; the cross-sectional view of the NiTi continuous filament / aluminum matrix composite material prepared in Example 4 is shown in Figure 4. Figure 8 As shown.

[0074] from Figure 7 It can be seen that the NiTi continuous filament / aluminum matrix composite material prepared in Comparative Example 1 has large unfilled defects in its structure, and the bond between the NiTi continuous filament and the aluminum matrix is ​​not tight.

[0075] from Figure 8 It can be seen that the structure of the NiTi continuous filament / aluminum matrix composite material prepared in Example 4 has only a small number of unbonded defects in some areas, and the bonding between the NiTi filament and the aluminum matrix is ​​tight.

[0076] The performance of the NiTi continuous filament / aluminum matrix composite material prepared in Comparative Example 1 was tested, and the results showed that the tensile strength was only 67.3 MPa, indicating poor mechanical properties.

[0077] The performance of the NiTi continuous filament / aluminum matrix composite material prepared in Example 4 was tested, and the results showed that the tensile strength was 182.5 MPa, indicating good mechanical properties.

[0078] As can be seen from Example 1, Comparative Example 1 and Example 4, the present invention can further increase the interfacial bonding between NiTi continuous wire and aluminum substrate by optimizing process parameters.

[0079] As can be seen from the above embodiments and comparative examples, the preparation method provided by the present invention can increase the degree of bonding between the NiTi continuous wire and the aluminum substrate interface, and the arrangement and content of the NiTi continuous wire are adjustable, and the process is simple.

[0080] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a NiTi continuous filament / aluminum-based composite material, characterized in that, Includes the following steps: (1) An aluminum substrate was prepared by friction stir additive manufacturing to obtain a deposited layer; (2) The deposited layer obtained in step (1) is grooved, and then NiTi continuous filament is filled in the groove. Then, aluminum-based material is filled in the groove by friction stirring additive manufacturing to obtain NiTi continuous filament / aluminum-based composite material.

2. The preparation method according to claim 1, characterized in that, The thickness of the deposited layer in step (1) is 1~4 mm.

3. The preparation method according to claim 1, characterized in that, The depth of the groove in step (2) is 0.5~1.5mm.

4. The preparation method according to claim 1, characterized in that, In step (2), the diameter of the NiTi continuous wire is 0.5~1.5mm.

5. The preparation method according to claim 4, characterized in that, In step (2), the NiTi continuous filament is pretreated before use. The pretreatment includes grinding, cutting, acid treatment, cleaning and drying in sequence.

6. The preparation method according to claim 1, characterized in that, Step (2) further includes filling the groove with powdered zinc-aluminum based brazing filler metal after filling the groove with NiTi continuous wire.

7. The preparation method according to claim 1, characterized in that, The process parameters for friction stir additive manufacturing in step (2) include: rotation speed 1500~1700rpm, travel speed 110~130mm / min, and wire feeding speed 1~3m / min.

8. The preparation method according to claim 1, characterized in that, In step (2), after the aluminum-based material is filled in the tank by friction stirring additive manufacturing, an aging heat treatment is also performed; the holding temperature of the aging heat treatment is 100~150℃, and the holding time of the aging heat treatment is 10~16h.

9. The NiTi continuous filament / aluminum-based composite material prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the NiTi continuous filament / aluminum matrix composite material of claim 9 in advanced electronic intelligent switches, automotive intelligent rear wings, intelligent skins, intelligent engine exhaust nozzles, and intelligent engine exhaust lips.

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