Additive manufacturing method of aluminum-steel composite material and application thereof

Abstract

The application discloses an additive preparation method of aluminum-steel composite material and application thereof, and comprises the following steps: S1, laser preheating treatment is conducted on aluminum alloy raw materials to obtain aluminum alloy; and S2, the aluminum alloy additive is conducted on a base material steel plate by adopting a friction stir additive process to obtain the aluminum-steel composite material. The application combines solid-phase additive with various exogenous auxiliary process technologies, laser heat sources are introduced to preheat the aluminum alloy raw materials in the friction stir additive process, the softening degree of the materials can be well improved, the metal fluidity in the additive process is improved, the heat input required in the additive process is reduced, and the generation of defects such as cracks and pores is effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy technology, and more specifically to a forming method for aluminum alloys and its application. Background Technology

[0002] Aluminum-steel composites are in high demand due to their combination of the low density and corrosion resistance of aluminum and its alloys with the high strength of steel. For example, in shipbuilding, aluminum-steel composites can provide a stable connection between the deck (steel) and the cabin (aluminum alloy), ensuring the safe operation of the vessel. However, the physical and chemical properties of aluminum alloys and steel differ significantly, making effective bonding impossible using traditional fusion welding. The main advantages of rolling composite methods include: the ability to composite metals in sheets, bars, tubes, and wires; lower cost; higher output; and a mature process suitable for large-scale industrial production. The main disadvantages include: oxidation of raw materials cannot be avoided during the rolling composite process; and the bond between the two metals is unstable, representing a typical mechanical bonding process. When using explosive welding to prepare aluminum-steel composites, the poor chemical or metallurgical compatibility of aluminum and iron leads to the formation of numerous hard and brittle compounds at the interface, severely impacting the bonding quality and hindering engineering applications. Therefore, in actual production, pure titanium or pure aluminum is often introduced as a transition layer between the aluminum alloy and steel to improve the bonding quality. However, the interface is a weak point in composite materials. Using a transition layer in the preparation of aluminum-steel composites creates two interfaces within the material, increasing the risk of failure. The significant differences in thermophysical and chemical properties between aluminum and steel increase the difficulty of joining dissimilar metals like aluminum and steel. Aluminum and steel have low miscibility, and welding easily forms hard and brittle intermetallic compounds (IMCs), such as FeAl2, Fe2Al5, and FeAl3, increasing joint brittleness. The large differences in the coefficients of linear expansion and thermal conductivity between aluminum and steel lead to significant residual stress after welding, which easily promotes crack initiation and propagation. Furthermore, the formation of a refractory Al2O3 oxide film on the aluminum alloy surface during welding affects the degree of fusion of the weld metal and reduces weld quality. For joining dissimilar metals like aluminum and steel, friction stir welding (FSM) is a suitable method. Solid-state welding (FSW), as a solid-state joining technology, utilizes the heat generated by friction between a high-speed rotating stirring head and the workpiece, as well as the heat generated by material deformation, to locally plasticize the materials being welded. The plasticized material flows under the stirring action of the stirring pins and forms a dense solid-state weld under the pressure of the welding tool. Its low heat input and short thermal cycle time can effectively control the growth of intermetallic compounds (IMCs), while also reducing welding stress and minimizing defects such as cracks and porosity caused by the melting-solidification process. It has become a research hotspot in aluminum / steel dissimilar material welding. The FSW process involves complex frictional heat generation and shear deformation behavior. The material near the friction interface is mainly subjected to thermo-mechanical coupling effects provided by temperature and deformation force, causing a series of physical phenomena such as plastic deformation, flow, and atomic diffusion.Larger plastic deformation rates lead to crystal defects such as supersaturated vacancies, dislocations, and stacking faults, as well as internal stresses at the interface, reducing the atomic diffusion activation energy and promoting atomic diffusion kinetics. The intense plastic deformation during friction stir treatment refines grains, breaks down second-phase particles, shortens diffusion distances, and shifts the diffusion rate from bulk diffusion to tube diffusion along dislocations, increasing the diffusion rate by 1000 times. Therefore, in the aluminum / steel FSW process, due to intense plastic deformation, atoms at the interface diffuse into each other, forming metallic bonds and generating a series of Fe-Al IMCs, achieving metallurgical bonding between aluminum and steel dissimilar metals. Reliable bonding of aluminum / steel dissimilar metals is closely related to interfacial behavior, and the thickness and type of Fe-Al IMCs play a crucial role in interfacial bonding. The formation of IMCs at the aluminum / steel interface enables metallurgical bonding, enhancing joint strength and fatigue performance compared to purely mechanical bonding. However, excessive IMCs can lead to phase volume changes, generating localized stresses, facilitating crack initiation and propagation, and reducing the joint's load-bearing capacity.

[0003] Therefore, existing aluminum-steel composite material preparation processes are prone to defects such as cracks and pores, which affect the mechanical properties of the material. Summary of the Invention

[0004] The present invention aims to solve the aforementioned technical problems existing in the prior art. To this end, the present invention proposes an additive manufacturing method for aluminum-steel composite materials, which combines solid-phase additive manufacturing with various external auxiliary processing technologies to obtain high-performance and highly reliable dissimilar metal material interfaces.

[0005] This invention also proposes the application of an additive manufacturing method for aluminum-steel composite materials in the preparation of components for the transportation sector.

[0006] According to one aspect of the present invention, an additive manufacturing method for aluminum-steel composite materials is provided, comprising the following steps:

[0007] S1. Aluminum alloy is obtained by laser preheating of aluminum alloy raw materials;

[0008] S2. An aluminum-steel composite material is obtained by using friction stir additive manufacturing process to add aluminum alloy to a base steel plate.

[0009] The first aspect of the present invention has at least the following beneficial effects:

[0010] This invention discloses a solid-phase additive manufacturing technology for aluminum-steel composite materials. It combines solid-phase additive manufacturing with various external auxiliary processes. During the stirring and mixing additive process, a laser heat source is introduced to preheat the aluminum alloy raw material, which effectively improves the material's softening degree, enhances metal fluidity during additive manufacturing, and reduces the heat input required. The lower heat input avoids material melting during additive manufacturing; instead, the metal layers are bonded through solid-phase diffusion, effectively preventing defects such as cracks and porosity.

[0011] In some embodiments of the present invention, the preparation method further includes: cooling the aluminum-steel composite material in step S2 at -250 to -150°C for 20 to 120 minutes.

[0012] In some embodiments of the present invention, the preparation method further includes: cooling the aluminum-steel composite material in step S2 at -200 to -150°C for 20 to 120 minutes.

[0013] In some embodiments of the present invention, the cooling process further includes heat treatment.

[0014] In some embodiments of the present invention, the temperature of the heat treatment is 150–250°C.

[0015] The additively prepared aluminum-steel composite material is placed in a coolant for 20 to 120 minutes at a temperature of -150 to -250°C. Then it is taken out and rapidly heated to a temperature of 150 to 250°C. This extreme cold and heat treatment can generate a large number of dislocations, strengthen the substrate, and eliminate residual stress.

[0016] In some embodiments of the present invention, the temperature of the laser preheating treatment is 200–300°C.

[0017] In some embodiments of the present invention, the laser power of the laser preheating treatment is 1 to 5 kW; the beam diameter of the laser preheating treatment is 0.5 to 1.5 mm.

[0018] In some embodiments of the present invention, the parameters of the friction stir additive manufacturing process include: the rotational speed of the stirring head is 1000-2000 r / min.

[0019] In some embodiments of the present invention, the parameters of the friction stir additive manufacturing process include: the rotational speed of the stirring head is 1000-2000 r / min.

[0020] In some embodiments of the present invention, the parameters of the friction stir additive process include: additive speed: 50-200 mm / min.

[0021] In some embodiments of the present invention, the parameters of the friction stir additive process include: additive speed: 90-110 mm / min.

[0022] In some embodiments of the present invention, the parameters of the friction stir additive manufacturing process include: interaxial pressure of 0.5 to 2 mm.

[0023] In some embodiments of the present invention, the parameters of the friction stir additive manufacturing process include: a stirring head tilt angle of 1 to 5°.

[0024] In some embodiments of the present invention, the parameters of the friction stir additive manufacturing process include: a stirring head tilt angle of 2 to 4°.

[0025] In some embodiments of the present invention, the friction stir additive manufacturing process further includes ultrasonic assistance.

[0026] In some embodiments of the present invention, the parameters of the ultrasound assistance include: an ultrasonic vibration frequency of 10 to 50 kHz.

[0027] In some embodiments of the present invention, the parameters of the ultrasound assistance include: an ultrasonic vibration frequency of 20 to 40 kHz.

[0028] In some embodiments of the present invention, the parameters of the ultrasound assistance include an amplitude of 10–40 μm.

[0029] In some embodiments of the present invention, the parameters of the ultrasound assistance include an amplitude of 20–40 μm.

[0030] In some embodiments of the present invention, the parameters of the ultrasound assistance include: ultrasound power of 1 to 4 kW.

[0031] In some embodiments of the present invention, the parameters of the ultrasound assistance include: ultrasound power of 2 to 4 kW.

[0032] In some embodiments of the present invention, a cooling medium is used to cool the substrate steel plate during the friction stir additive manufacturing process.

[0033] In some embodiments of the present invention, the flow rate of the cooling medium is 10-30 L / min, and the cooling rate of the cooling medium is 10-30 °C / s.

[0034] In some embodiments of the present invention, the temperature of the cooling medium is 10–80°C.

[0035] In some embodiments of the present invention, the flow rate of the cooling medium is 15-25 L / min, and the cooling rate of the cooling medium is 15-25 °C / s.

[0036] The use of a cooling medium to cool the substrate (steel) improves the thermal conductivity of the substrate, achieves grain refinement, and enhances mechanical properties. The cooling medium can effectively reduce welding heat input, control the growth of interfacial IMCs, reduce the thickness of the IMCs layer, and prevent the formation of coarse and brittle compounds. Rapid cooling can improve the grain structure, thereby improving the mechanical properties of the joint.

[0037] Ultrasonic assistance and cooling media can effectively reduce welding heat input, control the growth of interfacial IMCs, and rapid cooling can improve grain structure, thereby enhancing the mechanical properties of the joint. Therefore, the combination of solid-state additive manufacturing with various external auxiliary processes holds promise for achieving low-cost, highly stable, and high-quality welding / additive manufacturing of dissimilar metal materials, resulting in high-performance and highly reliable dissimilar metal interfaces.

[0038] This invention combines solid-state additive manufacturing with various external auxiliary processes. Introducing laser heat sources and ultrasound during the stirring and friction additive manufacturing process effectively improves material softening and controls heat input. By simultaneously introducing ultrasound into the additive manufacturing process with the FSW process, ultrasound can cause IMCs to break down, reducing the IMC layer thickness. Furthermore, the introduction of additional mechanical energy by ultrasound helps soften the material, reduces friction, lowers heat input, and inhibits IMC growth. Solid-state additive manufacturing under a cooling medium can reduce the temperature of the stirring zone and interface, increase the cooling rate, and obtain ultrafine equiaxed grains. The presence of the cooling medium can quickly absorb the heat generated by stirring friction, reducing heat input and increasing the cooling rate. Less heat reduces the diffusion rate and duration between Al and Fe atoms, thereby reducing the thickness of the IMCs. The faster cooling rate refines the grain structure in the weld nugget, significantly improving the mechanical strength of the joint.

[0039] According to a second aspect of the present invention, an additive manufacturing method for aluminum-steel composite materials is proposed for use in the manufacture of components in the transportation sector. Detailed Implementation

[0040] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment provides an additive manufacturing method for aluminum-steel composite materials, comprising the following steps:

[0043] S1. A laser is used to preheat 7075 aluminum alloy raw material (the raw material has dimensions of 50mm width, 200mm length, and 6mm thickness). The laser power is 2kW, the beam diameter is 1.0mm, and the preheating temperature is 240℃.

[0044] S2. Using a friction stir additive manufacturing process (where the stirring head rotation speed is 1000 r / min, the additive speed is 100 mm / min, the inter-shaft pressure is 1 mm, the stirring head tilt angle is 3°; the ultrasonic vibration frequency is 30 kHz, the amplitude is 30 μm, and the ultrasonic power is 3 kW), 7075 aluminum alloy is additively processed on a base steel plate to obtain an aluminum-steel composite material. The additively prepared aluminum-steel composite material is then placed in a coolant at a temperature of -180℃ for 60 minutes, and then taken out and rapidly heated to a temperature of 170℃, using an extreme cold and extreme heat treatment.

[0045] The additive manufacturing process uses coolant for cooling, and the substrate (steel) is cooled by a cooling medium (temperature of 30℃) with a flow rate of 20L / min and a cooling rate of 20℃ / s.

[0046] Example 2

[0047] This embodiment provides an additive manufacturing method for aluminum-steel composite materials, comprising the following steps:

[0048] S1. Laser is used to preheat 7075 aluminum alloy raw materials. Laser power: 2kW, beam diameter: 1.0mm.

[0049] Preheating temperature 240℃;

[0050] S2. Using a friction stir additive manufacturing process (where the stirring head rotation speed is 1500 r / min, the additive speed is 100 mm / min, the inter-shaft pressure is 1 mm, the stirring head tilt angle is 3°; the ultrasonic vibration frequency is 30 kHz, the amplitude is 30 μm, and the ultrasonic power is 3 kW), 7075 aluminum alloy is additively processed on a base steel plate to obtain an aluminum-steel composite material. The additively prepared aluminum-steel composite material is then placed in a coolant at a temperature of -180℃ for 60 minutes, and then taken out and rapidly heated to a temperature of 170℃, using an extreme cold and extreme heat treatment.

[0051] The additive manufacturing process uses coolant for cooling, and the substrate (steel) is cooled by a cooling medium with a flow rate of 20 L / min and a cooling rate of 20 °C / s.

[0052] Example 3

[0053] This embodiment provides an additive manufacturing method for aluminum-steel composite materials, comprising the following steps:

[0054] S1. Laser is used to preheat 7075 aluminum alloy raw materials. Laser power: 2kW, beam diameter: 1.0mm.

[0055] Preheating temperature 240℃;

[0056] S2. Using a friction stir additive manufacturing process (where the stirring head rotation speed is 2000 r / min, the additive speed is 100 mm / min, the inter-shaft pressure is 1 mm, the stirring head tilt angle is 3°; the ultrasonic vibration frequency is 30 kHz, the amplitude is 30 μm, and the ultrasonic power is 3 kW), 7075 aluminum alloy is additively processed on a base steel plate to obtain an aluminum-steel composite material. The additively prepared aluminum-steel composite material is then placed in a coolant at a temperature of -180℃ for 60 min, and then taken out and rapidly heated to a temperature of 170℃, using an extreme cold and extreme heat treatment.

[0057] The additive manufacturing process uses coolant for cooling, and the substrate (steel) is cooled by a cooling medium with a flow rate of 20 L / min and a cooling rate of 20 °C / s.

[0058] Comparative Example 1

[0059] This comparative example provides an additive manufacturing method for aluminum-steel composite materials. The difference between this comparative example and Example 1 is that it does not include preheating treatment and ultrasonic assistance. The specific steps are as follows:

[0060] S1. Using friction stir additive manufacturing process (where the stirring head speed is 1000 r / min, the additive speed is 100 mm / min, the inter-shaft pressure is 1 mm, and the stirring head tilt angle is 3°), 7075 aluminum alloy is additively processed on the base steel plate to obtain aluminum-steel composite material. The aluminum-steel composite material prepared by additive manufacturing is placed in a coolant for 60 min at a temperature of -180℃, and then taken out and rapidly heated to a temperature of 170℃, using extreme cold and extreme heat treatment.

[0061] The additive manufacturing process uses coolant for cooling, and the substrate (steel) is cooled by a cooling medium with a flow rate of 20 L / min and a cooling rate of 20 °C / s.

[0062] Comparative Example 2

[0063] This comparative example provides an additive manufacturing method for aluminum-steel composite materials. The difference between this comparative example and Example 1 is that it does not include the preheating treatment and cooling in the additive manufacturing steps. Specifically, the steps are as follows:

[0064] S1. Using a friction stir additive manufacturing process (where the stirring head speed is 1000 r / min, the additive speed is 100 mm / min, the inter-shaft pressure is 1 mm, and the stirring head tilt angle is 3°), 7075 aluminum alloy is additively processed on a base steel plate to obtain an aluminum-steel composite material. The additively prepared aluminum-steel composite material is then placed in a coolant at a temperature of -180℃ for 60 minutes. After that, it is taken out and rapidly heated to a temperature of 170℃, which is an extreme cold and extreme heat treatment.

[0065] Comparative Example 3

[0066] This comparative example provides an additive manufacturing method for aluminum-steel composite materials, specifically comprising the following steps:

[0067] S1. Heat 7075 aluminum alloy and 316 stainless steel to 350℃ and roll them together using a rolling mill with a rolling reduction of 10%.

[0068] S2. The rolled composite material is subjected to solution treatment at a temperature of 470℃ for 2 hours. After removal, it is water-quenched and then subjected to aging heat treatment at 120℃ for 24 hours.

[0069] Comparative Example 4

[0070] This comparative example provides an additive manufacturing method for aluminum-steel composite materials. The difference between this comparative example and Example 1 is that the laser preheating step in Example 1 is replaced, while the other conditions are the same.

[0071] This embodiment provides an additive manufacturing method for aluminum-steel composite materials, comprising the following steps:

[0072] S1. TIG argon arc heating is used to preheat the 7075 aluminum alloy raw material. The argon arc current is 8A. The preheating temperature is 240℃.

[0073] S2. Using a friction stir additive manufacturing process (where the stirring head rotation speed is 1000 r / min, the additive speed is 100 mm / min, the inter-shaft pressure is 1 mm, the stirring head tilt angle is 3°; the ultrasonic vibration frequency is 30 kHz, the amplitude is 30 μm, and the ultrasonic power is 3 kW), 7075 aluminum alloy is additively processed on a base steel plate to obtain an aluminum-steel composite material. The additively prepared aluminum-steel composite material is then placed in a coolant at a temperature of -180℃ for 60 minutes, and then taken out and rapidly heated to a temperature of 170℃, using an extreme cold and extreme heat treatment.

[0074] The additive manufacturing process uses coolant for cooling, and the substrate (steel) is cooled by a cooling medium with a flow rate of 20 L / min and a cooling rate of 20 °C / s.

[0075] TIG (Tranquilizing Induction Heat) preheating has a low energy density, resulting in a long preheating time and uneven temperature. Aluminum dissipates heat quickly, leading to poor preheating effect and poor metal flow during the stirring additive manufacturing process. This results in alumina entrapment and void defects, reducing performance. Laser, on the other hand, has a high energy density, provides fast and uniform preheating, and can also remove the oxide film on the aluminum surface, thus achieving excellent results.

[0076] Comparative Example 5

[0077] This comparative example provides an additive manufacturing method for aluminum-steel composite materials. The difference between this comparative example and Example 1 is that the ultrasonic-assisted step in Example 1 is replaced, while the other conditions are the same.

[0078] S1. Laser is used to preheat 7075 aluminum alloy raw materials. Laser power: 2kW, beam diameter: 1.0mm.

[0079] Preheating temperature 240℃;

[0080] S2. Using friction stir additive manufacturing process (where the stirring head rotation speed is 1000 r / min, the additive speed is 100 mm / min, the inter-shaft pressure is 1 mm, and the stirring head tilt angle is 3°; the electromagnetic field excitation current is 1~10A, the frequency is 10~100Hz, and the magnetic field strength is 1~100mT), 7075 aluminum alloy is additively processed on the base steel plate to obtain aluminum-steel composite material. After obtaining the aluminum-steel composite material prepared by additive manufacturing, it is placed in a coolant at a temperature of -180℃ for 60 minutes, and then taken out and rapidly heated to a temperature of 170℃, using extreme cold and extreme heat treatment.

[0081] The additive manufacturing process uses coolant for cooling, and the substrate (steel) is cooled by a cooling medium with a flow rate of 20 L / min and a cooling rate of 20 °C / s.

[0082] Electromagnetic fields can soften materials and improve fluidity, but they cannot effectively break up large aluminum-iron compounds at the interface, nor can they hinder the formation and growth of IMCs. Therefore, the strength and shear strength are not high.

[0083] Test case

[0084] The performance of the embodiments and comparative examples is shown in Table 1.

[0085] Mechanical property testing standard: GB / T 228.1-2021;

[0086] Table 1 Performance Results

[0087]

[0088]

[0089] This invention discloses a solid-state additive manufacturing technology for aluminum-steel composite materials. It combines solid-state additive manufacturing with various external auxiliary processes. During the stirring and friction additive manufacturing process, a laser heat source is introduced to preheat the aluminum alloy raw material, which effectively improves the material softening degree, enhances metal fluidity during additive manufacturing, and reduces the heat input required. By simultaneously introducing ultrasound and the FSW process into the additive manufacturing process, ultrasound can, on the one hand, cause IMCs to fracture, reducing the IMC layer thickness and preventing the formation of coarse, brittle compounds; on the other hand, ultrasound introduces additional mechanical energy, which helps soften the material, reduces friction, lowers heat input, and inhibits IMC growth. Solid-state additive manufacturing under a cooling medium can reduce the temperature of the stirring zone and interface, increase the cooling rate, and obtain ultrafine equiaxed grains. Since steel has poor cooling efficiency, cooling is performed on the substrate (steel). The presence of a cooling medium can quickly absorb the heat generated by stirring and friction, reducing heat input and increasing the cooling rate. Less heat reduces the diffusion rate and duration between Al and Fe atoms, thereby reducing the thickness of the IMCs. The rapid cooling rate refines the grain structure in the weld nugget, significantly improving the mechanical strength of the joint. Ultrasonic assistance and cooling media effectively reduce welding heat input, control the growth of intermetallic compounds (IMCs) at the interface, and rapid cooling improves the grain structure, thereby enhancing the mechanical properties of the joint. Therefore, the combination of solid-state additive manufacturing with various external auxiliary processes holds promise for achieving low-cost, highly stable, and high-quality welding / additive manufacturing of dissimilar metal materials, resulting in high-performance and highly reliable dissimilar metal interfaces. As can be seen from the test results in Table 1, the combination of solid-state additive manufacturing with various external auxiliary processes in this invention significantly improves the strength, elongation, and shear strength of the prepared composite material, significantly reduces the thickness of the intermetallic compounds, and significantly refines the grain structure of the additive-manufactured aluminum alloy.

[0090] Comparative Example 1 does not include preheating treatment and ultrasonic assistance, which reduces the fluidity of the material. During the additive manufacturing process, the aluminum alloy material is deposited unevenly, resulting in poor forming quality and the appearance of cracks or pores. At the same time, without ultrasonic assistance, it is impossible to reduce the resistance to plastic deformation and fluidity of the metal material, and it is also impossible to cause the IMCs to break, resulting in an increase in the thickness of the IMCs layer and the formation of coarse and brittle compounds.

[0091] Comparative Example 2, which excludes the cooling operation in the preheating and additive manufacturing steps, cannot maintain good material flowability, resulting in uneven interlayer fusion. It also exacerbates the formation of IMCs, leading to increased joint brittleness and reduced mechanical properties of the composite material. Without the cooling step, the welding heat input cannot be effectively reduced, resulting in increased IMC layer thickness, which in turn affects strength and shear strength.

[0092] Comparative Example 3 uses hot rolling to composite aluminum and steel, followed by solution treatment. This high-temperature, long-duration heat treatment method results in the formation of thick IMCs at the aluminum-steel interface, with a large number of coarse and brittle aluminum-iron compounds, leading to poor bonding performance of aluminum and steel and low strength and shear strength.

[0093] In Comparative Example 4, TIG argon arc preheating was performed. Due to the low energy density of the argon arc, the preheating time was long and the preheating temperature was uneven. The aluminum dissipated heat relatively quickly, resulting in poor preheating effect. This led to poor metal fluidity during the stirring additive manufacturing process, alumina entrapment and void defects, and reduced performance.

[0094] Comparative Example 5 uses an electromagnetic field, which has a certain softening effect on the material and improves its fluidity. However, it cannot effectively break up the coarse aluminum-iron compounds between the interfaces, nor can it hinder the formation and growth of IMCs. Therefore, its strength and shear strength are not high.

[0095] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. An additive manufacturing method for aluminum-steel composite materials, characterized in that: Includes the following steps: S1. An aluminum alloy is obtained by laser preheating treatment of aluminum alloy raw materials, wherein the laser preheating treatment temperature is 200~300℃, the laser power is 1~5kW, and the laser beam diameter is 0.5~1.5mm; S2. Aluminum alloy additive manufacturing is carried out on a base steel plate using friction stir additive manufacturing process. After additive manufacturing, the plate is cooled at -250 to -150℃ for 20-120 minutes and then heated at 150-250℃ to obtain an aluminum-steel composite material. The friction stir additive manufacturing process also includes ultrasonic assistance; the parameters of the ultrasonic assistance include: ultrasonic vibration frequency of 10-50 kHz, amplitude of 10-40 μm, and ultrasonic power of 1-4 kW; the parameters of the friction stir additive manufacturing process include: stirring head rotation speed of 1000-2000 r / min; additive speed of 50-200 mm / min, inter-shaft compression of 0.5-2 mm, and stirring head tilt angle of 1-5°; In the process of friction stir additive manufacturing, a cooling medium is used to cool the substrate steel plate. The flow rate of the cooling medium is 10-30 L / min, and the cooling rate of the cooling medium is 10-30 °C / s.

2. The application of the additive manufacturing method of aluminum-steel composite material as described in claim 1 in the preparation of components in the transportation field.

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