Steel-aluminum transition joint and solid phase deformation driving deposition manufacturing method thereof

Abstract

The application discloses a steel-aluminum transition joint and a solid-phase deformation driving deposition manufacturing method thereof, and relates to a transition joint and a deposition manufacturing method thereof. In order to solve the problem that the steel-aluminum transition joint is prone to generating brittle intermetallic compounds, thereby causing the performance of the joint to deteriorate, the steel-aluminum transition joint comprises a deposited aluminum alloy, a steel material and a Si-containing micro-layer; the deposited aluminum alloy and the steel material are sequentially arranged from top to bottom, and the Si-containing micro-layer is arranged between the deposited aluminum alloy and the steel material. The application belongs to the technical field of dissimilar material connection.

Description

Technical Field

[0001] The invention relates to a transition joint and a deposition manufacturing method thereof, belonging to the technical field of dissimilar material connection. Background Art

[0002] In many fields such as automobiles, ships, and aerospace, steel-aluminum composite structures are gradually replacing traditional all-steel structures to meet the design requirements of lightweight, energy-saving and emission-reduction. However, the huge difference in physical properties between steel and aluminum makes it difficult to connect heterogeneous materials. In addition, due to the metallurgical reaction between aluminum and steel, a large amount of brittle intermetallic compounds (Fe2Al5, Fe4Al 13 etc.), which reduces the strength of the steel-aluminum transition interface and leads to the deterioration of the bearing performance of the entire joint.

[0003] Silicon (Si) atoms have a lower chemical potential at the steel-aluminum interface and tend to diffuse preferentially there. Furthermore, Si can effectively reduce the activity coefficient of aluminum atoms, thereby reducing the thickness of the diffusion layer between the steel and aluminum metals. Therefore, appropriately introducing Si at the interface helps control the thickness of the intermetallic compound at the interface, thereby improving the mechanical properties of the joint. Furthermore, the introduction of Si can alter the structure of the intermetallic compound, generating relatively tougher compounds such as Fe(Al,Si) and Fe2Al8Si, effectively reducing joint stress and improving joint mechanical properties.

[0004] The solid-phase deformation-driven deposition method, developed from friction stir welding technology, uses a rotating threaded stirring head and a stationary material storage chamber to achieve the thermal plasticization and deposition process of the material. Because this process does not involve melting and solidification of the material, it can effectively avoid defects such as pores and cracks in steel-aluminum transition joints. In addition, due to the low heat input of this process, it can effectively control the thickness of the intermetallic compound and reduce the residual stress in the joint, thereby improving the mechanical properties of the joint. The solid-phase deposition additive method can more flexibly prepare steel-aluminum transition joints with different shape requirements in a "point-by-point and layer-by-layer, breaking the whole into parts" approach, providing greater freedom in production.

[0005] Therefore, by using the solid-phase deformation-driven deposition method and designing a Si-containing microlayer at the interface, the production and preparation of high-performance steel-aluminum transition joints with high freedom can be achieved, which has important application value in the automotive, shipbuilding and aerospace fields. Summary of the Invention

[0006] The present invention aims to solve the problem that brittle intermetallic compounds are easily generated in steel-aluminum transition joints, which leads to deterioration of joint performance, and further proposes a steel-aluminum transition joint and a solid-phase deformation-driven deposition manufacturing method thereof.

[0007] The technical solution adopted by the present invention to solve the above problems is as follows: the steel-aluminum transition joint of the present invention comprises a deposited aluminum alloy, a steel material and a Si-containing microlayer;

[0008] The deposited aluminum alloy and the steel are arranged in sequence from top to bottom, and the Si-containing microlayer is arranged between the deposited aluminum alloy and the steel.

[0009] The steps of the solid phase deformation driven deposition manufacturing method of the present invention include:

[0010] Step 1, preparing Si microlayer;

[0011] Step 2: Solid phase deformation driven deposition.

[0012] Furthermore, in step 101, a steel material with a thickness of 1 to 50 mm is prepared, the oxide layer on the surface to be deposited is removed, and oil and dust are cleaned;

[0013] Step 102: Using Si-containing material as raw material, the surface of the steel is enriched with Si, and a Si-containing microlayer with a thickness of about 5 to 500 μm is formed.

[0014] Furthermore, Si-enrichment methods include solid phase deformation driven deposition, friction stir deposition, hot dip plating, magnetron sputtering and silanization.

[0015] Furthermore, step 2 specifically includes:

[0016] Step 201: delivering the wire material for preparing the steel-aluminum transition joint to a deformation-driven deposition device through a wire feeding mechanism;

[0017] Step 202: The wire entering the device is sheared and transported by the mutual movement between the tools in the device;

[0018] Step 203: thermal plasticization of the material is achieved under the action of frictional heat and large plastic deformation, and the deposition process of the material is further completed;

[0019] Step 204: Various aluminum alloys are deposited on the steel with Si-rich surface treatment by the deformation-driven deposition method, thereby enabling the preparation of various steel-aluminum transition joints.

[0020] Furthermore, the Si-containing microlayer includes a pure Si layer, an Al-Si alloy layer, a Fe-Si alloy layer and a Fe-Al-Si alloy layer, and has a thickness of 5 to 500 μm.

[0021] Furthermore, a Si-containing aluminum alloy wire with a diameter of Φ1.2-3.0 mm is delivered to a deformation-driven deposition device through a wire feeding mechanism, and a Si-containing microlayer with a thickness of 100-500 μm is obtained at parameters of 300-1500 rpm and 10-200 mm / min.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention designs a Si-containing microlayer at the steel-aluminum transition interface to regulate the metallurgical reaction at the interface, improve the types of intermetallic compounds at the interface, avoid the formation of brittle intermetallic compounds, and reduce the residual stress of the joint. By controlling the thickness of the Si-containing layer, the steel-aluminum interface is strengthened while ensuring the overall mechanical properties of the joint, thereby improving the mechanical properties of the joint.

[0024] 2. The solid-phase deformation-driven deposition method promotes dynamic recovery and recrystallization of the material through large plastic deformation, achieving ultrafine or even nano-crystallization of the grain structure. Under the forging action of the lower end surface of the static storage chamber, an ultra-dense deposited aluminum alloy with extremely low porosity is formed, thereby ensuring the overall mechanical properties of the steel-aluminum joint.

[0025] 3. The deformation-driven deposition method can break down the steel-aluminum transition joint into smaller pieces. The steel-aluminum transition joint is prepared by a point-by-point and layer-by-layer deposition method. This method offers greater freedom in structural design and can produce joints of various shapes and sizes. Furthermore, this method has the advantage of geothermal input, effectively controlling the growth of intermetallic compounds and reducing residual stress in the joint, which is beneficial for improving the mechanical properties of the joint.

[0026] 4. The ultrafine grain structure obtained by introducing Si-containing microlayers at the interface and deformation-driven deposition method can break through the technical bottleneck of high-reliability steel-aluminum transition joints. In addition, this method does not involve the melting-resolidification process, which significantly reduces the energy required for the production of steel-aluminum transition joints, reduces the process difficulty, and avoids the defects caused by the melting-solidification process. It is a green manufacturing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of the T-steel aluminum transition joint containing Si microlayers according to the present invention;

[0028] Figure 2 This is a schematic structural diagram of the ring-shaped steel-aluminum transition joint containing Si microlayers according to the present invention;

[0029] Figure 3 This is a schematic structural diagram of the tubular steel-aluminum transition joint containing Si microlayers according to the present invention;

[0030] Figure 4 is a schematic diagram of the deformation driven deposition method of the present invention;

[0031] Figure 5 It is a schematic structural diagram of the stirring head and the static material storage chamber of the present invention.

[0032] Figures 1 to 5In the figure, 1-deposited aluminum alloy, 2-steel, 3-Si-containing microlayer, 4-deformation-driven deposition device, 401-stirring head, 402-storage chamber, 40101-clamping part, 40102-threaded part, 4010-stirring needle, 40201-wire feeding hole, 40202-lower end surface, 403-wire, 404-wire feeding mechanism. DETAILED DESCRIPTION

[0033] Specific implementation method 1: Figures 1 to 3 As shown, a steel-aluminum transition joint comprises a deposited aluminum alloy (1), a steel material (2) and a Si-containing microlayer (3);

[0034] The deposited aluminum alloy (1) and the steel material (2) are arranged in sequence from top to bottom, and the Si-containing microlayer (3) is arranged between the deposited aluminum alloy (1) and the steel material (2).

[0035] Specific implementation method 2: Figure 4 and Figure 5 As shown, a solid phase deformation driven deposition manufacturing method for the steel-aluminum transition joint as claimed in the claim comprises the following specific steps:

[0036] Step 1: Prepare steel with a thickness of 1 to 50 mm, remove the oxide layer on the surface to be deposited, and clean the oil and dust; use Si-containing material as raw material and prepare a Si-containing microlayer through surface Si-enrichment methods such as solid phase deformation driven deposition, stir friction deposition, hot dip plating, magnetron sputtering or silanization to form a Si-containing microlayer with a thickness of about 5 to 500 μm on the surface of the steel 2;

[0037] Step 2: The wire 403 for the steel-aluminum transition joint is delivered to the deformation-driven deposition device 4 via a wire feeder 404. The wire 403 enters the device, where it is sheared and transported through the interplay between tools within the device. Frictional heat and large plastic deformation result in thermal plasticization of the material, further completing the deposition process. This deformation-driven deposition method allows for the deposition of various aluminum alloys onto the steel 2 containing a Si microlayer, enabling the fabrication of a wide variety of steel-aluminum transition joints.

[0038] The deformation driven deposition device 4 is composed of a rotating stirring head 401 and a stationary material storage chamber 402 coordinated therewith.

[0039] Specific implementation method 2: Figures 1 to 3 As shown, the steel material 2 is one of non-alloy steel, low alloy steel, alloy steel and stainless steel, and its length is 10 mm to 1000 mm.

[0040] Specific implementation method three: Figures 1 to 3As shown, the Si-containing layer 3 is one of a pure Si layer, an Al-Si alloy layer, a Fe-Si alloy layer, and a Fe-Al-Si alloy layer, and has a thickness of 5 to 500 μm.

[0041] Specific implementation method four: Figures 1 to 3 As shown, the deposited aluminum alloy 1 is one of Al-Cu alloy, Al-Mg alloy, Al-Si alloy, and Al-Zn-Mg-Cu alloy.

[0042] Specific implementation method five: Figure 4 and Figure 5 As shown, the Si-containing materials described in the preparation method of the Si-containing microlayer 3 structure include but are not limited to Si-containing aluminum alloys, silane treatment agents and pure Si; the Si-containing materials can be selected from various forms of raw materials such as wire, powder, silane and solution according to different surface Si-enrichment methods.

[0043] Specific implementation method six: Figure 4 and Figure 5 As shown, the surface Si-enriched method described in the preparation method of the Si-containing microlayer 3 structure includes but is not limited to deformation driven deposition, stir friction deposition, hot dip plating, magnetron sputtering and silanization methods;

[0044] Among them, the Si-enrichment method can realize the preparation of Si-containing microlayers with a Si content of 1 to 100% and a thickness of 5 to 500 μm.

[0045] Specific implementation method seven: Figure 4 and Figure 5 As shown, the solid-phase deformation-driven deposition method described in the preparation method of the Si-containing microlayer 3 structure transmits the Si-containing aluminum alloy wire with a diameter of Φ1.2 to 3.0 mm into the deformation-driven deposition device 4 through the wire feeding mechanism 404 and obtains the Si-containing microlayer 3 with a thickness of 100 to 500 μm at the parameters of 300 to 1500 rpm and 10 to 200 mm / min.

[0046] Specific implementation eight: Figure 4 and Figure 5 As shown, the friction stir deposition method described in the preparation method of the Si-containing micro-layer 3 structure uses the Si-containing aluminum alloy rod to achieve the process of thermal plasticization and deposition by utilizing the friction heat and large plastic deformation process between the aluminum alloy rod and the surface of the steel 2;

[0047] The Si-containing microlayer 3 having a thickness of 100 to 500 μm can be formed at parameters of 200 to 2000 rpm and 10 to 200 mm / min.

[0048] Specific implementation method nine: Figure 4 and Figure 5As shown, the hot dip plating method described in the preparation method of the Si-containing microlayer 3 structure is to pickle, degrease, rinse and dry the surface of the steel 2, and then use a Si-containing plating solution and perform immersion plating in a protective gas.

[0049] Among them, it can be heated to 750-800℃ at a speed of 5-20℃ / s and kept warm for 80-150s, then cooled to the dipping temperature of 0-5℃ above at a cooling rate of 5-20℃ / s to start dipping, and then cooled to room temperature at a speed of 10-25℃ / s after dipping.

[0050] Specific implementation method ten: Figure 4 and Figure 5 As shown, the magnetron sputtering method described in the preparation method of the Si-containing microlayer 3 structure can use single crystal Si or FeSi alloy as raw material, the target material diameter is 50-70 mm, the thickness is 3-4 mm, and the target-substrate distance is 25-35 mm. Under the working pressure of 0.5-1 Pa, the target material is heated to 4.6-5.0 W·cm -2 The power density is deposited on the surface of steel 2.

[0051] Specific implementation method 11: Figure 4 and Figure 5 As shown, the rotating stirring head 401 is composed of a clamping part 40101, a threaded part 40102 and a stirring needle 40103 at the end. The threaded structure of the threaded part 40102 can realize the shearing and transmission process of the material, and the stirring needle 40103 at the end can enhance the material flow behavior between different deposition layers and achieve good bonding between the deposition layers.

[0052] Specific implementation method 12: Figure 4 and Figure 5 As shown, the static material storage chamber 402 and the rotating stirring head 401 should cooperate with each other, and a clearance fit is satisfied between the two, with the clearance being 0.2 to 1.0 mm.

[0053] The storage chamber 402 has two structures, namely a wire feeding hole 40201 and a lower end surface 40202 . The lower end surface 40202 can exert a forging effect on the newly deposited material, which is beneficial to optimizing the structure of the deposited material and improving its performance.

[0054] Specific implementation method thirteen: Figure 4 and Figure 5 As shown, the material deposition process can use aluminum alloy wire with a diameter of Φ1.2 to 3.0 mm, and obtain a dense aluminum alloy deposition layer with a single layer thickness of 1.0 to 2.0 mm under the parameters of 300 to 1500 rpm and 100 to 1000 mm / min.

[0055] Specific implementation method 14: Figure 4 and Figure 5As shown, the material deposition process can select aluminum alloy rods with a diameter of Φ10 to 30 mm, and obtain a dense aluminum alloy deposition layer with a single layer thickness of 1.0 to 4.0 mm under the parameters of 300 to 1500 rpm and 100 to 1000 mm / min.

[0056] Example

[0057] Example 1:

[0058] This embodiment utilizes a steel-aluminum transition joint and a solid phase deformation driven deposition manufacturing method thereof in the following steps:

[0059] 1. Preparation of Si-containing microlayer structures

[0060] Prepare 316L stainless steel with a thickness of 1 to 50 mm, remove the oxide layer from the surface to be deposited, and clean it. Use 4043 aluminum alloy wire with a diameter of 1.2 to 3.0 mm as the raw material. This wire is fed into a deformation-driven deposition device (consisting of a rotating stirring head and a stationary storage chamber) via a wire feed mechanism, where shearing, thermal plasticization, and deposition are carried out. At deposition parameters of 600 rpm-50 mm / min, a Si-containing deposited layer with a thickness of approximately 500 μm is formed on the steel surface.

[0061] 2. Deformation-driven deposition method

[0062] A 2.4mm diameter 2219 aluminum alloy wire is fed through a wire feeding mechanism into a deformation-driven deposition device (consisting of a rotating stirring head and a stationary storage chamber), where shearing, thermoplasticization, and deposition processes are performed. A travel speed of 450rpm-150mm / min is used, and the thickness of the deposited layer is 1.6mm. The stirring needle at the bottom of the stirring head is 2mm long and 4mm in diameter at the root. The needle penetrates the 4043 aluminum alloy layer to a depth of 0.4mm. The stirring needle fully mixes the 4043 aluminum alloy with the 2219 aluminum alloy, improving joint performance.

[0063] Example 2:

[0064] This embodiment utilizes a steel-aluminum transition joint and a solid phase deformation driven deposition manufacturing method thereof in the following steps:

[0065] 1. Preparation of Si-containing microlayer structures

[0066] The 40Cr steel surface to be deposited was ground and polished, then rinsed with deionized water and ultrasonically cleaned with alcohol. It was then immersed in a sodium hydroxide solution for 6 minutes, rinsed with clean water, and then immersed in a 15% HCl solution for 2 minutes. After deionized water and alcohol cleaning, the steel surface was subjected to flux plating in a 5% K2ZrF6 aqueous solution at 88°C and then dried in a drying oven at 120°C / h for 60 seconds. Anodization was performed in an electrolyte solution of 175g / L sulfuric acid and 7g / L oxalic acid. Finally, the steel surface was silanized using KH560 in a mixture of 6mL KH560, 20mL anhydrous ethanol, and 75mL deionized water at 70°C for 5 minutes, resulting in a silane layer approximately 20μm thick.

[0067] 2. Deformation-driven deposition method

[0068] A 7075 aluminum alloy rod with a diameter of 20 mm is fed into a friction stir deposition device (consisting of a hollow stirring head) through a wire feed mechanism. The rod is then heat-plasticized and deposited under the action of friction heat and large plastic deformation with the steel plate surface. The first deposition layer is 2.0 mm thick, and the deposition parameters are 700 rpm to 225 mm / min. The stirring needle at the bottom of the stirring head is 2.0 mm long and has a root diameter of 4 mm. The stirring needle makes micro-contact with the Si-containing microlayer on the steel surface. The subsequent deposition process achieves a single layer thickness of 1.8 mm, and the parameters are 700 rpm to 250 mm / min, with the stirring needle penetrating 0.2 mm into the previous layer.

[0069] Example 3:

[0070] This embodiment utilizes a steel-aluminum transition joint and a solid phase deformation driven deposition manufacturing method thereof in the following steps:

[0071] 1. Preparation of Si-containing microlayer structures

[0072] Prepare 3mm thick low silicon steel, grind and polish the surface, and remove the oxide layer and oil stains on the surface to be deposited. Use N-type single crystal Si wafer with a diameter of 60mm and a thickness of 3.5mm, and the target-substrate distance is 30mm. Under the working pressure of 0.8Pa, the target is 4.86W·cm -2 The sample was then placed in a vacuum heat treatment furnace for diffusion treatment. Finally, a pure Si film with a surface thickness of approximately 5 μm was obtained.

[0073] 2. Deformation-driven deposition method

[0074] A pure aluminum wire with a diameter of Φ2.4mm is fed into a deformation-driven deposition device (consisting of a rotating stirring head and a stationary storage chamber) through a wire feeding mechanism, where shearing, thermoplasticization, and deposition processes are performed. The thickness of the first deposition layer is 2.0mm, and the deposition parameters are 1200rpm-450mm / min. The stirring needle at the bottom of the stirring head is 2.0mm long and has a root diameter of 4mm. The stirring needle is in micro-contact with the Si-containing microlayer on the steel surface. The subsequent deposition process has a single layer thickness of 1.6mm, and the parameters are 1200rpm-600mm / min, with the stirring needle penetrating 0.4mm into the previous layer.

[0075] Example 4:

[0076] This embodiment utilizes a steel-aluminum transition joint and a solid phase deformation driven deposition manufacturing method thereof in the following steps:

[0077] 1. Preparation of Si-containing microlayer structures

[0078] The surface of 22MnB5 hot-formed steel is ground and polished, then cleaned to remove surface oxides and oil. A protective gas mixture of 95% N2 + 5% H2 is introduced, and a 90% Al-10% Si bath is used. The bath is heated to 780°C at a rate of 10°C / s and held for 120 seconds. The bath is then cooled at a rate of 10°C / s to a temperature 5°C above the dip-plating temperature before the dip-plating process begins. After dip-plating, the bath is cooled at a rate of 20°C / s to room temperature. This results in a Si-containing microlayer approximately 50μm thick.

[0079] 2. Deformation-driven deposition method

[0080] The Al-7Mg alloy wire with a diameter of Φ1.6mm is fed into a deformation-driven deposition device (consisting of a rotating stirring head and a stationary storage chamber) through a wire feeding mechanism, and the shearing, thermoplasticization and deposition processes are realized in the device. The thickness of the first deposition layer is 2.0mm, and the deposition parameters are 600rpm-225mm / min. The stirring needle at the bottom of the stirring head is 2.0mm long and the root diameter is 4mm. The stirring needle is in micro-contact with the Si-containing microlayer on the steel surface. The subsequent deposition process has a single layer thickness of 1.6mm, and the parameters are 600rpm-300mm / min. The stirring needle penetrates 0.4mm into the previous layer.

[0081] Example 5:

[0082] The surface of 316L stainless steel with a thickness of 15mm was ground and polished, and then cleaned to remove surface oxides and oil stains. The Al-Si alloy wire with a diameter of Φ2.4mm was fed into the deformation-driven deposition device (consisting of a rotating stirring head and a static storage chamber) through the wire feeding mechanism, and the shearing, thermoplasticization and deposition processes were realized in the device. The thickness of the first deposition layer was 1.2mm, and the deposition parameters were 400rpm-120mm / min. The stirring needle at the bottom of the stirring head was 1.2mm long and 2mm in diameter at the root. The stirring needle was in micro-contact with the steel surface. The thickness of the single layer in the subsequent deposition process was 1.0mm, and the parameters were 400rpm-100mm / min. The stirring needle penetrated 0.2mm into the previous layer.

[0083] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement of the above embodiments made according to the technical essence of the present invention, within the spirit and principles of the present invention, without departing from the content of the technical solution of the present invention, shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A solid phase deformation driven deposition manufacturing method for a steel-aluminum transition joint, characterized in that: The steel-aluminum transition joint used in the method comprises a deposited aluminum alloy (1), a steel material (2) and a Si-containing microlayer (3); The deposited aluminum alloy (1) and the steel (2) are arranged in sequence from top to bottom, and the Si-containing microlayer (3) is arranged between the deposited aluminum alloy (1) and the steel (2); The solid phase deformation driven deposition manufacturing method refers to a friction stir deposition method; Step 1: preparing Si microlayer (3); specifically comprising: Step 101: prepare steel (2) with a thickness of 1 to 50 mm, remove the oxide layer on the surface to be deposited and clean the oil and dust; Step 102: Si-enriching the surface of the steel (2) with a Si-containing material as a raw material, delivering a Si-containing aluminum alloy wire (403) with a diameter of Φ1.2-3.0 mm to a deformation-driven deposition device (4) through a wire feeding mechanism (404), and obtaining a Si-containing microlayer (3) with a thickness of 100-500 μm at parameters of 300-1500 rpm and 10-200 mm / min; Step 2: solid phase deformation driven deposition; specifically comprising: Step 201: The wire material (403) for preparing the steel-aluminum transition joint is conveyed to the deformation-driven deposition device (4) via the wire feeding mechanism (404); Step 202, the wire material (403) entering the device is sheared and transported by the mutual movement between the tools in the device; Step 203: thermal plasticization of the material is achieved under the action of frictional heat and large plastic deformation, and the deposition process of the material is further completed; Step 204: Various aluminum alloys are deposited on the steel material (2) with a surface Si-rich treatment by using the deformation-driven deposition method, thereby enabling the preparation of various steel-aluminum transition joints.

2. The solid phase deformation driven deposition manufacturing method for a steel-aluminum transition joint according to claim 1, characterized in that: Methods for Si enrichment include hot-dip plating, magnetron sputtering, and silanization.

3. The solid phase deformation driven deposition manufacturing method for a steel-aluminum transition joint according to claim 1, characterized in that: The Si-containing microlayer (3) includes a pure Si layer, an Al-Si alloy layer, a Fe-Si alloy layer, and a Fe-Al-Si alloy layer, and has a thickness of 5 to 500 μm.

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