An asymmetric, alternating forming, deformation-free additive joining method for large thickness metal components

Abstract

The application discloses a kind of asymmetric alternate forming deformation prevention additive connection methods of large-thickness metal components, belong to additive manufacturing and welding technical field.The asymmetric alternate forming deformation prevention additive connection methods of large-thickness metal components of the application, comprising the following steps: the end face of the large-thickness metal component to be connected is machined X-type groove, after assembly and fixation, the front and back forming of X-type groove is completed by additive manufacturing alternately, and finally stress relief annealing treatment is carried out;The thickness d of large-thickness metal component is greater than or equal to 40mm;Front and back forming adopts asymmetric alternate forming mode.The additive connection method of the application solves the bottleneck problem of large deformation and high risk of cracking existing in current additive connection technology, increases the maximum connection thickness of metal component to 200mm, and the maximum deformation angle is less than 0.3 degrees.

Description

Technical Field

[0001] This invention relates to the fields of additive manufacturing and welding technology, and in particular to an asymmetric alternating forming anti-deformation additive joining method for thick metal components. Background Technology

[0002] Large-scale integrated structural design and large, complex integral metal components are important ways to achieve lightweighting in major equipment. However, with the rapid development of large-scale integrated metal components, traditional single manufacturing technologies such as casting, forging, and additive manufacturing face serious bottlenecks in manufacturing capacity and efficiency. Manufacturing methods that separate and connect large, complex integral metal components have significant advantages. Currently, the most widely used connection methods in engineering are high-energy beam welding or additive bonding, such as laser, electron beam, and electric arc welding. However, high-energy beam welding has limitations in two aspects: firstly, the thickness of the welded plate is limited; for example, the thickness of titanium alloy plates welded by electron beam welding in mature industrial applications does not exceed 70mm, and thicker plates are prone to poor fusion. Secondly, high-energy beam welding is limited by the thickness and geometry of the base material, resulting in a large heat-affected zone and significant deformation and cracking risks. Additive bonding also suffers from large deformation and cracking risks. Therefore, how to solve the bottleneck problems of large deformation and cracking risks in connecting large, complex integral metal components using current technologies and realize their application in the field of major equipment has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0003] The purpose of this invention is to provide an asymmetric alternating forming anti-deformation additive joining method for thick metal components, so as to solve the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention provides the following solution: an asymmetric alternating forming and deformation-resistant additive joining method for thick metal components, comprising the following steps: X-shaped bevels are machined on the end faces of the thick metal components to be connected. After assembly and fixation, additive manufacturing is used to alternately form the front and back sides of the X-shaped bevels. Finally, stress-relieving annealing is performed. The thickness d of the thick metal component is ≥ 40 mm; The front and back sides are formed using an asymmetrical alternating forming method.

[0005] Preferably, the thickness d of the thick metal component is 40~200mm.

[0006] Preferably, the material of the thick metal component includes titanium alloy, steel, high-temperature alloy, aluminum alloy, magnesium alloy or high-entropy alloy.

[0007] Preferably, the angle of the X-shaped bevel is 20 to 90 degrees, and the contact end face of the X-shaped bevel is a vertical step with a horizontal length L of 1 to 4 mm and a vertical height H of 2 to 8 mm.

[0008] More preferably, the thick metal components to be connected are assembled and fixed on a device with a rotation function.

[0009] Preferably, the front and back forming includes: The front side is formed for the first time, and the two contact ends are connected by laser remelting (i.e., no powder is fed). The first forming on the reverse side has a forming height d1 of 0.025~0.25d; The front side is formed for the second time, with a forming height of d2, and d1 < d2 ≤ 2d1; The reverse side undergoes a second forming process with a forming height of d3, where d2 < d3 ≤ 2d2. The front side is formed for the third time, with a forming height of d4, and d3 < d4 ≤ 2d3; When d3≥0.5d-d1, d3 is taken as 0.5d-d1, and the reverse side forming is completed; When d4≥0.5d-d2, d4 is taken as 0.5d-d2, and the front side is formed. When d1+d3<0.5d or d2+d4<0.5d, continue alternating forming of the front and back sides until the additive connection of the two bevels is completed at 100% height.

[0010] More preferably, the total number of forming times for the front and back sides is determined according to the specific selection value of d1, and the front and back sides are formed alternately until the additive connection of 100% height of the two bevels is completed.

[0011] Preferably, during the first forming of the front side, process parameters should be reasonably selected to ensure that the depth of laser remelting is greater than 50% of the end face contact height H, thus ensuring the connection strength of the first layer of additive bonding.

[0012] Preferably, the additive manufacturing includes powder-fed laser-directed energy deposition additive manufacturing.

[0013] Preferably, the raw material used in the powder-feeding laser-directed energy deposition additive manufacturing is: metal spherical powder with the same chemical composition as the thick metal component to be joined.

[0014] Preferably, the particle size of the metal spherical powder is 53~250μm.

[0015] Preferably, the additive manufacturing process parameters include: a spot diameter of 3-8 mm (the spot diameter should be no less than 2 mm). LLaser power 2~8kW, scanning rate 500~1500mm / min, powder feeding rate 500~2000g / h, overlap rate 30~60%, single layer height increase 0.3~1.0mm, argon protective atmosphere, oxygen content <100ppm.

[0016] Compared with traditional welding technology, the powder-feeding laser directional energy deposition additive manufacturing joining technology of the present invention has outstanding advantages such as not being limited by the thickness and geometry of the base material and having a small heat-affected zone.

[0017] Preferably, the process parameters for the stress-relief annealing heat treatment are determined based on the grade of the metal component material and the recommended commonly used stress-relief annealing heat treatment process.

[0018] This invention utilizes a novel additive joining process employing an X-shaped bevel and asymmetric, incremental, alternating forming method to significantly reduce deformation and cracking risk in additive joining of thick metal components. The basic principle is that deformation during additive manufacturing is positively correlated with the number of layers and volume formed in a single pass. After each pass, when a certain height is formed on one side, the sample in the joining area deforms and generates internal stress under tensile stress. Moving to the other side and continuing forming generates the opposite internal stress, thus offsetting the internal stress and deformation from the previous pass. Therefore, the incremental alternating forming process completely eliminates the accumulated deformation and internal stress, solving the bottleneck problem of large deformation and high cracking risk in joining large, complex, integral metal components using current technologies.

[0019] The present invention discloses the following technical effects: (1) The additive connection method of the present invention solves the bottleneck problems of large deformation and high risk of cracking in the current additive connection technology, increases the maximum connection thickness of metal components to 200mm, and its maximum deformation angle is less than 0.3 degrees.

[0020] (2) The main process parameters and equipment used in the additive bonding method of the present invention are exactly the same as those used in additive manufacturing, and no special research or updates are required. In addition, the applicable metal material grades are also the same as those used in additive manufacturing, mainly including common metal materials such as titanium alloys, steel, high-temperature alloys, aluminum alloys, magnesium alloys, and high-entropy alloys. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the additive bonding method of the present invention; Figure 2 This is a schematic diagram of the X-shaped bevel geometry parameters of the thick metal component to be connected according to the present invention. Figure 3 This is a schematic diagram of the process of alternating forming of the front and back sides in additive bonding according to the present invention; Figure 4 A photograph of a 120mm thick titanium alloy component prepared according to Example 1 of the present invention; Figure 5 A photograph of a 120mm thick titanium alloy component prepared according to Example 2 of the present invention; Figure 6 Here is a photograph of a 120mm thick titanium alloy component prepared in Comparative Example 1 of this invention. Figure 7 A photograph of a 200mm thick titanium alloy component prepared according to Example 3 of the present invention. Detailed Implementation

[0023] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0024] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0025] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0026] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0027] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0028] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0029] In a specific embodiment of the present invention, an asymmetric alternating forming anti-deformation additive joining method for thick metal components is provided, comprising the following steps: X-shaped bevels are machined on the end faces of the thick metal components to be connected. After assembly and fixation, additive manufacturing is used to alternately form the front and back sides of the X-shaped bevels. Finally, stress-relieving annealing is performed. For thick metal components, the thickness d ≥ 40 mm; The front and back sides are formed using an asymmetrical alternating forming method.

[0030] Preferably, the thickness d of the thick metal component is 40~200mm; Preferably, the materials used for thick metal components include common metal materials such as titanium alloys, steel, high-temperature alloys, aluminum alloys, magnesium alloys, or high-entropy alloys.

[0031] Preferably, the angle of the X-shaped bevel is 20 to 90 degrees, and the contact end face of the X-shaped bevel is processed into a vertical step with a horizontal length L of 1 to 4 mm and a vertical height H of 2 to 8 mm.

[0032] More preferably, the thick metal components to be connected are assembled and fixed on a device with a rotation function.

[0033] Preferably, the front and back forming includes: The front side is formed for the first time, without powder feeding, and the two contact ends are connected by laser remelting. The first forming on the reverse side has a forming height d1 of 0.025~0.25d; The front side is formed for the second time, with a forming height of d2, and d1 < d2 ≤ 2d1; The reverse side undergoes a second forming process with a forming height of d3, where d2 < d3 ≤ 2d2. The front side is formed for the third time, with a forming height of d4, and d3 < d4 ≤ 2d3; When d3≥0.5d-d1, d3 is taken as 0.5d-d1, and the reverse side forming is completed; When d4≥0.5d-d2, d4 is taken as 0.5d-d2, and the front side is formed. When d1+d3<0.5d or d2+d4<0.5d, continue alternating forming of the front and back sides until the additive connection of the two bevels is completed at 100% height.

[0034] More preferably, the total number of forming times for the front and back sides is determined according to the specific selection value of d1, and the front and back sides are formed alternately until the additive connection of 100% height of the two bevels is completed.

[0035] Preferably, during the first forming of the front side, process parameters should be reasonably selected to ensure that the depth of laser remelting is greater than 50% of the end face contact height H, thus ensuring the connection strength of the first layer of additive bonding.

[0036] Preferably, additive manufacturing includes powder-fed laser-directed energy deposition additive manufacturing.

[0037] Preferably, the raw material used in the powder-feeding laser-directed energy deposition additive manufacturing is: metal spherical powder with the same chemical composition as the thick metal component to be joined.

[0038] Preferably, the particle size of the metal spherical powder is 53~250μm.

[0039] Preferably, the additive manufacturing process parameters include: a spot diameter of 3~8mm (the spot diameter should be no less than 2mm). L Laser power 2~8kW, scanning rate 500~1500mm / min, powder feeding rate 500~2000g / h, overlap rate 30~60%, single layer height increase 0.3~1.0mm, argon protective atmosphere, oxygen content <100ppm.

[0040] Preferably, the process parameters for stress-relief annealing heat treatment are determined based on the grade of the metal component material and the recommended commonly used stress-relief annealing heat treatment process.

[0041] A schematic diagram of the additive bonding method is shown below. Figure 1 A schematic diagram of the X-groove geometry parameters for the thick metal components to be connected is shown below. Figure 2 A schematic diagram of the additive bonding process, involving alternating forming of the front and back sides, is shown below. Figure 3 .

[0042] Example 1 An asymmetric alternating forming and deformation-resistant additive joining method for thick metal components (TB18 titanium alloy components): (1) The two titanium alloy components with a maximum thickness of d of 120 mm to be connected are processed into X-shaped bevels with an angle of 70 degrees. The contact end face of the X-shaped bevel is processed into a vertical step with a horizontal length L of 2 mm and a vertical height H of 4 mm.

[0043] (2) Assemble and fix the two metal components on the rotating platform, which can rotate 360 ​​degrees.

[0044] (3) Prepare TB18 titanium alloy spherical powder with the same chemical composition as the metal components to be connected, with a particle size range of 75~250μm.

[0045] (4) The front and back sides of the X-shaped bevel are formed alternately by additive manufacturing. The first front side is formed without powder feeding, and the two contact ends are connected by laser remelting (the height of laser remelting is 60% of the height H of the contact ends); the first back side is formed with a forming height d1 of 30 mm (50% of 0.5d); the second front side is formed with a forming height d2 of 60 mm (2d1), and the front side is formed; the second back side is formed with a forming height d3 of 30 mm (0.5d-d1), and the back side is formed, thus obtaining the additively connected metal component.

[0046] Among them, the additive manufacturing is a powder-fed laser directional energy deposition additive manufacturing process with the following parameters: spot diameter 6mm, laser power 6kW, scanning rate 1000mm / min, powder feeding rate 1000g / h, overlap rate 40%, single layer height increase 0.5mm, argon protective atmosphere, and oxygen content <100ppm.

[0047] (5) The additively connected metal components are subjected to stress-relief annealing. The stress-relief annealing heat treatment process is to hold at 530℃ for 4 hours and then air cool to obtain the additively connected titanium alloy components.

[0048] The additively joined titanium alloy component prepared in this embodiment was tested and analyzed, and the results are shown in the figure. Figure 4 .

[0049] from Figure 4 As can be seen, the quality of the joint area of ​​the additive connection is good, no macro cracks were found, and the deformation angle of the parent material of the additive connection component is 0.25 degrees.

[0050] Example 2 An asymmetric alternating forming and deformation-resistant additive joining method for thick metal components (TB18 titanium alloy components): (1) The two titanium alloy components with a maximum thickness of d of 120 mm to be connected are processed into X-shaped bevels with an angle of 70 degrees. The contact end face of the X-shaped bevel is processed into a vertical step with a horizontal length L of 2 mm and a vertical height H of 4 mm.

[0051] (2) Assemble and fix the two metal components on the rotating platform, which can rotate 360 ​​degrees.

[0052] (3) Prepare TB18 titanium alloy spherical powder with the same chemical composition as the metal components to be connected, with a particle size range of 75~250μm.

[0053] (4) The front and back sides of the X-shaped bevel are formed alternately by additive manufacturing. The first front side is formed without powder feeding, and the two contact ends are connected by laser remelting (the height of laser remelting is 60% of the height H of the contact ends); the first back side is formed with a forming height d1 of 6 mm (10% of 0.5d); the second front side is formed with a forming height d2 of 12 mm (2d1); the second back side is formed with a forming height d3 of 24 mm (2d2); the third front side is formed with a forming height d4 of 48 mm (2d3), and the front side forming is completed; the third back side is formed with a forming height d5 of 30 mm (0.5d-d1-d3), and the back side forming is completed, obtaining the additively connected metal component.

[0054] Among them, the additive manufacturing is a powder-fed laser directional energy deposition additive manufacturing process with the following parameters: spot diameter 6mm, laser power 6kW, scanning rate 1000mm / min, powder feeding rate 1000g / h, overlap rate 40%, single layer height increase 0.5mm, argon protective atmosphere, and oxygen content <100ppm.

[0055] (5) The additively connected metal components are subjected to stress-relief annealing. The stress-relief annealing heat treatment process is to hold at 530℃ for 4 hours and then air cool to obtain the additively connected titanium alloy components.

[0056] The additively joined titanium alloy component prepared in this embodiment was tested and analyzed, and the results are shown in the figure. Figure 5 .

[0057] from Figure 5 As can be seen, the quality of the joint area of ​​the additive connection is good, no macro cracks were found, and the deformation angle of the parent material of the additive connection component is 0.10 degrees.

[0058] Comparative Example 1 Same as in Example 2, except that step (4) is as follows: the front and back sides of the X-shaped bevel are formed by additive manufacturing. First, the first front side is formed without powder feeding, and the two contact surfaces are connected by laser remelting (the laser remelting height is 60% of the contact surface height H). The first back side is formed with a forming height of 60mm, and the back side is formed. The second front side is formed with a forming height of 60mm, and the front side is formed.

[0059] The additively joined titanium alloy components prepared in this comparative example were tested and analyzed. The results are shown in the figure. Figure 6 .

[0060] from Figure 6 As can be seen, the quality of the joint area of ​​the additive bonding is good, and no macroscopic cracks were found. The deformation angle of the parent material of the additive bonding sample is 3 degrees, and its deformation is 30 times that of Example 2.

[0061] Example 3 An asymmetric alternating forming and deformation-resistant additive connection method for thick metal components (TC4-DT titanium alloy components): (1) The two titanium alloy components with a maximum thickness d of 200mm to be connected are processed into X-shaped bevels with an angle of 80 degrees. The contact end face of the X-shaped bevel is processed into a vertical step with a horizontal length L of 2mm and a vertical height H of 4mm.

[0062] (2) Assemble and fix the two metal components on the rotating platform, which can rotate 360 ​​degrees.

[0063] (3) Prepare TC4-DT titanium alloy spherical powder with the same chemical composition as the metal components to be connected, with a particle size range of 75~250μm.

[0064] (4) The front and back sides of the X-shaped bevel are formed alternately by additive manufacturing. The first front side is formed without powder feeding, and the two contact ends are connected by laser remelting (the height of laser remelting is 60% of the height H of the contact ends); the first back side is formed with a forming height d1 of 10 mm (10% of 0.5d); the second front side is formed with a forming height d2 of 20 mm (2d1); the second back side is formed with a forming height d3 of 40 mm (2d2); the third front side is formed with a forming height d4 of 80 mm (2d3), and the front side is formed; the third back side is formed with a forming height d5 of 50 mm (0.5d-d1-d3), and the additively connected metal component is obtained.

[0065] Among them, the additive manufacturing is a powder-fed laser directional energy deposition additive manufacturing process with the following parameters: spot diameter 6mm, laser power 6kW, scanning rate 1000mm / min, powder feeding rate 1000g / h, overlap rate 40%, single layer height increase 0.5mm, argon protective atmosphere, and oxygen content <100ppm.

[0066] (5) The additively connected metal components are subjected to stress-relief annealing. The stress-relief annealing heat treatment process is to keep at 600℃ for 4 hours and then air cool to obtain the additively connected titanium alloy components.

[0067] The additively joined titanium alloy component prepared in this embodiment was tested and analyzed, and the results are shown in the figure. Figure 7 .

[0068] from Figure 7 As can be seen, the quality of the additively joined joint area is good, with no macroscopic cracks found, and the deformation angle of the base material in the additively joined sample is 0.12 degrees. This demonstrates that even with a thickness increased to 200 mm, the deformation of the additively joined titanium alloy component remains very small.

[0069] The method of this invention can achieve the connection of titanium alloy components with X-shaped bevel angles of 20 to 90 degrees. The connection area has good quality, no macroscopic cracks were found, and the deformation angle of the parent material of the additive connection sample does not exceed 0.3 degrees.

[0070] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for asymmetric alternating forming and deformation-resistant additive bonding of thick metal components, characterized in that, Includes the following steps: X-shaped bevels are machined on the end faces of the thick metal components to be connected. After assembly and fixation, additive manufacturing is used to alternately form the front and back sides of the X-shaped bevels. Finally, stress-relieving annealing is performed. The thickness d of the thick metal component is ≥ 40 mm; The front and back sides are formed using an asymmetrical alternating forming method.

2. The asymmetric alternating forming anti-deformation additive connection method for thick metal components according to claim 1, characterized in that, The thickness d of the thick metal component is 40~200mm.

3. The asymmetric alternating forming anti-deformation additive connection method for thick metal components according to claim 1, characterized in that, The materials of the thick metal components include titanium alloys, steel, high-temperature alloys, aluminum alloys, magnesium alloys, or high-entropy alloys.

4. The asymmetric alternating forming anti-deformation additive connection method for thick metal components according to claim 1, characterized in that, The angle of the X-shaped bevel is 20 to 90 degrees, and the contact end face of the X-shaped bevel is a vertical step with a horizontal length L of 1 to 4 mm and a vertical height H of 2 to 8 mm.

5. The asymmetric alternating forming anti-deformation additive connection method for thick metal components according to claim 1, characterized in that, The front and back forming includes: The front side is formed for the first time, and the two contact surfaces are connected by laser remelting. The first forming on the reverse side has a forming height d1 of 0.025~0.25d; The front side is formed for the second time, with a forming height of d2, and d1 < d2 ≤ 2d1; The reverse side undergoes a second forming process with a forming height of d3, where d2 < d3 ≤ 2d2. The front side is formed for the third time, with a forming height of d4, and d3 < d4 ≤ 2d3; When d3≥0.5d-d1, d3 is taken as 0.5d-d1, and the reverse side forming is completed; When d4≥0.5d-d2, d4 is taken as 0.5d-d2, and the front side is formed. When d1+d3<0.5d or d2+d4<0.5d, continue alternating between the front and back sides.

6. The asymmetric alternating forming anti-deformation additive connection method for thick metal components according to claim 5, characterized in that, During the first forming of the front side, the depth of laser remelting is greater than 50% of the end face contact height H.

7. The asymmetric alternating forming anti-deformation additive connection method for thick metal components according to claim 1, characterized in that, The additive manufacturing includes powder-feed laser-directed energy deposition additive manufacturing.

8. The asymmetric alternating forming anti-deformation additive connection method for thick metal components according to claim 7, characterized in that, The raw material used in the powder-feeding laser-directed energy deposition additive manufacturing is spherical metal powder with the same chemical composition as the thick metal component to be joined.

9. The asymmetric alternating forming anti-deformation additive connection method for thick metal components according to claim 8, characterized in that, The particle size of the metal spherical powder is 53~250μm.

10. The asymmetric alternating forming anti-deformation additive joining method for thick metal components according to claim 1, characterized in that, The additive manufacturing process parameters include: spot diameter 3~8mm, laser power 2~8kW, scanning rate 500~1500mm / min, powder feeding rate 500~2000g / h, overlap rate 30~60%, single layer height increase 0.3~1.0mm, argon protective atmosphere, and oxygen content <100ppm.

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