High-strength aluminum alloy friction stir welding seam defect repairing method and system

Abstract

The invention provides a high-strength aluminum alloy friction stir welding seam defect repairing method and system. The method comprises the steps that a to-be-repaired area is marked; calculating filling passes and the number of layers, planning a multi-layer and multi-channel filling path of the cross interface effect, and storing the multi-layer and multi-channel filling path in a three-dimensional model readable by equipment; determining repair manufacturing process parameters; importing a data model containing the contour of the to-be-repaired area, the number of filling layers and the filling pass of each layer into model processing software in a file format, and processing the repair model according to the repair manufacturing process parameters to obtain a filling repair path of the to-be-repaired part; and the repaired high-strength aluminum alloy component is prepared according to the repair manufacturing process parameters and the planned path in cooperation with a tool of additive repair equipment. On one hand, the problems that the high-strength aluminum alloy material shortage repairing filler is too high in heat input, large in influence on the performance of a base material and limited in performance improvement are solved, and on the other hand, the anisotropy between the performance of a filling area and the performance of the base body is effectively weakened.

Description

Technical Field

[0001] The present invention relates to the field of additive defect repair technology, and in particular, to a method and system for repairing defects in high-strength aluminum alloy friction stir welds, and in particular to a low heat input friction stir welding defect repair filler path design that has both lateral and longitudinal connection toughening and forms a mechanical interlocking interface. Background Art

[0002] Friction Stir Welding (FSW) is an advanced solid-state joining method invented by the Welding Institute (TWI) in 1991. This technology has the advantages of low heat input, high quality of welded joints, small welding deformation, insensitivity to temperature and humidity, and environmental protection, and is particularly suitable for welding aluminum alloy materials. Therefore, once FSW technology came out, it has attracted widespread attention from experts and scholars, and due to the significant technical and economic benefits of this technology, FSW technology has been widely used in aviation, aerospace, shipbuilding, automobile manufacturing, and rail vehicle processing and manufacturing.

[0003] The lightweight and high-strength characteristics of new aluminum alloys such as 2195 aluminum-lithium alloy provide more possibilities for the manufacture of large lightweight tanks. Due to the high sensitivity to thermal cracking, the quality of aluminum-lithium alloy fusion welding is poor. Due to high heat input, fatal defects such as holes and cracks are very likely to occur, and it is often difficult to completely avoid them by relying solely on parameter optimization. Therefore, the development of stir friction additive technology is crucial for the engineering application of aluminum-lithium alloys. However, defects such as weld thinning or sinking often occur during stir friction welding. Such defects are currently often treated by fusion welding and then stir friction welding to improve the organization, which has many problems: ①During the fusion welding process, the introduction of melting heat has a great influence on the microstructure and properties of the aluminum-lithium alloy matrix; ② Aluminum-lithium alloy currently lacks mature welding wire that has been verified by engineering applications; ③ The density of the fusion welding filling structure is poor, and defects still exist in the repaired part after stir friction welding.

[0004] Therefore, there is an urgent need to develop new additive repair methods for aluminum-lithium alloys, especially the design and repair technology of stir friction welding defect repair tools with low heat input to form a mechanical interlocking effect and metallurgical bonding.

[0005] Patent document CN209648007U discloses a device for repairing surface defects of aluminum alloy welds, including a base and a connecting block, a bottom slide groove is provided on the upper surface of the bottom of the base, the connecting blocks are symmetrically welded on both sides of the outside of the base, threaded holes are reserved inside the two sides of the base, and the inner side of the base is connected to the clamping plate through a spring, the top of the base is connected to the side rod through an upper rotating shaft, and side slide grooves are provided on both sides of the outside of the side rod, the side slider is installed on the side of the positioning block, and fixing columns are installed on the inner sides of the welding gun and the positioning block, and the fixing columns are connected to the side rod through fixing holes.

[0006] However, patent document CN209648007U cannot repair the friction stir welding defects that form mechanical interlocking effect and metallurgical bonding with low heat input.

[0007] In addition, common solid-phase repair technologies, such as stir friction additive manufacturing, rolling, powder metallurgy, etc., all have disadvantages such as limited repair shape and complex post-processing to varying degrees, and there is obvious anisotropy in the formed parts. The bonding mechanism between multiple passes and multiple layers and the weak interlayer bonding force are still problems that need to be solved, especially the problem of poor interface strength between the repair area and the substrate. Summary of the invention

[0008] In view of the defects in the prior art, the purpose of the present invention is to provide a method and system for repairing defects in high-strength aluminum alloy friction stir welds.

[0009] A high-strength aluminum alloy friction stir weld defect repair method provided by the present invention comprises: Step S1: Mark the area to be repaired and extract the outline of the area to be repaired; Step S2: Calculate the filling passes and the number of layers according to the distribution of the area to be repaired, plan the multi-layer and multi-pass filling paths of the cross-interface effect, and save them in a three-dimensional model that can be read by the device; Step S3: Determine repair manufacturing process parameters; Step S4: data model processing, importing the data model including the outline of the area to be repaired, the number of filling layers and the filling passes of each layer into the model processing software in a file format, completing the repair model processing according to the repair manufacturing process parameters, and obtaining the filling repair path of the part to be repaired; Step S5: preparing a repaired high-strength aluminum alloy component by cooperating with tools of the additive repair equipment according to the repair manufacturing process parameters and the path planned in step S4.

[0010] Preferably, in step S1, a three-dimensional model entity is established using computer-aided software according to the path and filling requirements of the repair tool, and the three-dimensional model entity is saved in a file format recognizable by the model processing software; The file formats include stl format and stp format.

[0011] Preferably, the step S2 includes extracting three-dimensional information of the area to be repaired, and calculating the number of filling passes and layers according to the three-dimensional information; The three-dimensional information includes the size of the area to be repaired, the width of a single pass, and the thickness of a single layer; The calculation formula for the number of filling layers and the number of filling passes per layer is as follows: N=(h+5) / t M=l or M=w / d Wherein, N represents the number of filling layers, M represents the number of filling passes in each layer, l, w, h represent the length, width, and height of the area to be repaired, respectively, d represents the width of a single layer, and t represents the thickness of a single layer.

[0012] Preferably, the step S3 includes a first process and a second process; The first process is to first use low heat input to supplement the material. At this time, there is no metallurgical and mechanical bonding between the filling material layers and the channels, and between the filling and supplementing areas and the substrate. The adjacent layers in the filling area are rotated 63° clockwise, and a non-linear close-packed filling method is used between the single layers to introduce a multi-interface effect. The second process is to use a repair tool with serrated features on the side to perform a homogenization treatment on the tissue modifier, thereby increasing the metallurgical bonding and mechanical locking effect between layers and paths in the repair area and between the repair area and the substrate.

[0013] Preferably, the heat input in the first process is less than that in the second process, and the heat input in the second process is less than the heat introduced by means including melting of the welding filler.

[0014] Preferably, in the step S4, a nonlinear dense arrangement is adopted in the single-layer pass of the filling area, and a wide contour filling method is adopted for the interface area between the prepared filling area and the substrate to cover all the interface areas.

[0015] Preferably, step S4 includes importing the three-dimensional format file generated in step S2 into the additive manufacturing slice layer model processing software, and according to the repair manufacturing parameters determined in step S3, t is the single layer thickness, d is the single lane laying spacing, and then planning the manufacturing path according to the contour of the area to be repaired, and generating a defect repair command file for the substrate filling path.

[0016] Preferably, in step S5, continuous non-linear paving is performed in the area to be repaired, so that the continuous passes are distributed at intersecting non-truncated interfaces, and a repair tool with a circumferential serrated structure is used to fill and modify the repair area to prepare a weakly anisotropic area to be repaired with multiple intersecting interfaces.

[0017] Preferably, a low-calorie filling method including stir friction additive is adopted, and the added material is filled in the area to be repaired in a poorly distributed manner, so that multiple contacts are formed between the continuous filled area and the filling material, and finally a low heat input, weakly anisotropic, high-strength aluminum alloy repair area is obtained.

[0018] A high-strength aluminum alloy friction stir weld defect repair system provided by the present invention comprises: Module M1: Mark the area to be repaired and extract the contour of the area to be repaired; Module M2: Calculate the filling passes and the number of layers according to the distribution of the area to be repaired, plan the multi-layer and multi-pass filling paths of the cross-interface effect, and save them in a three-dimensional model that can be read by the device; Module M3: Determine the repair manufacturing process parameters; Module M4: data model processing, importing the data model containing the outline of the area to be repaired, the number of filling layers and the filling passes of each layer into the model processing software in a file format, completing the repair model processing according to the repair manufacturing process parameters, and obtaining the filling repair path of the part to be repaired; Module M5: According to the repair manufacturing process parameters and the path planned by module M4, the tools of the additive repair equipment are coordinated to prepare the repaired high-strength aluminum alloy component.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts low-heat material adding methods such as stir friction material adding to replace the original high-heat input melting welding filler method. The filler part adopts an irregular wavy close-packed distribution method, which can effectively increase the multi-interface effect, alleviate the abnormal growth of the organization and the anisotropy of performance caused by a single heat input, effectively improve the comprehensive performance of the material, reduce the influence of heat input on the matrix, reduce the risk of thermal cracking, and at the same time break the limitation that high-strength aluminum alloy welds cannot be repaired multiple times.

[0020] Compared with the traditional solid-phase repair method, the present invention adopts a repair tool with a serrated structure on both sides, which can realize the material and heat exchange between the substrate and the filling area, and between the paths and layers of the filling area, forming a transverse and longitudinal interface distribution with both metallurgical bonding and mechanical locking effects. The bonding strength between the repair area and the substrate is improved, the interlayer bonding strength of the repair area is improved, and the anisotropy of the component is weakened.

[0021] The present invention invents a new filling method by optimizing the stirring tool, avoiding the high-energy heat input filling method of melt transition such as fusion welding, thereby avoiding coarse grains or even cracking of the high-strength aluminum alloy matrix due to excessive heat input; in addition, the material conversion efficiency between the repair area and the matrix is ​​increased through the structural design of the repair tool, and the single interface effect is weakened, thereby effectively weakening the poor interface performance between the repair layer and the matrix and the anisotropy of the performance of the multi-layer and multi-channel repair area. In particular, the serrated design of the side of the repair tool realizes the interlaced distribution of the repair area and the enhanced matrix structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 It is a schematic diagram of the working method of the present invention; Figure 2 A three-dimensional schematic diagram of the repair principle of high-strength aluminum alloy weld fillers with high strength and low anisotropy; Figure 3 To connect the layers and tracks after the repair is completed. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0024] The present invention optimizes the defect repair technology of improving the performance and organizational uniformity of high-strength aluminum alloy by nonlinear close-packed laying with low energy input and organizational modification methods that increase interlayer and inter-track material conversion, thereby improving the strength of the repaired area of ​​the prepared high-strength aluminum alloy and weakening the anisotropy of the performance between the filling area and the matrix. By using a low-heat input nonlinear filling material laying method and an organizational modification method with a high material exchange rate between the repair area and the matrix, a high-strength and weakly anisotropic high-strength aluminum alloy component is obtained. The repair objects of the present invention include defects caused by welding defects of high-strength aluminum alloys or damage during long-term service.

[0025] According to a high-strength aluminum alloy friction stir weld defect repair method provided by the present invention, Figure 1 As shown, including: Step S1: Mark the area to be repaired (filled) and extract the contour of the area to be repaired. According to the path and filling requirements of the repair tool, use computer-aided software to create a three-dimensional model entity and save it in a file format recognizable by the model processing software, such as stl and stp formats. For example, use computer-aided drawing software creo 2.0 or UG to extract the contour of the area to be repaired, including the three directions of X, Y, and Z. The outline is extended by 5mm compared to the actual outline, and the three-dimensional model is exported to stl or stp format.

[0026] Step S2: Calculate the filling passes and number of layers according to the distribution of the area to be repaired, plan the multi-layer and multi-pass filling path of the cross-interface effect, and save it in a 3D model that can be read by the device. According to the extracted 3D information of the area to be repaired, the 3D information includes: the size of the area to be repaired, the width of a single pass, and the thickness of a single layer. The calculation formula for the number of filling layers and the number of filling passes per layer is as follows: N=(h+5) / t M=l or M=w / d Wherein, N represents the number of filling layers, M represents the number of filling passes in each layer, l, w, h represent the length, width, and height of the area to be repaired, respectively, d represents the width of a single layer, and t represents the thickness of a single layer.

[0027] Filling method: Figure 2 As shown. The single layers are arranged in an interlaced manner, and the adjacent layers are rotated 63° to form a multiple interface effect of a non-single heat transfer path. The nth layer is distributed along the x direction, and the distribution is n (1), n ​​(2), n (3), n (4), n (5); the n+1 layer is rotated 63° clockwise compared to the n layer, and the distribution is n+1 (1), n+1 (2), n+1 (3), n+1 (4), n+1 (5). Among them, the laying direction of the nth layer of the filling material is rotated 63° clockwise from the laying axis between the n+1 layer. A nonlinear dense arrangement is adopted in the single layer of the filling area, and a wide contour filling method is adopted in the interface area between the prepared filling area and the substrate to cover all interface areas. For example: the substrate heating temperature is 250°C, the fiber head heating temperature is 250°C, the single layer thickness t is 2.5mm, the single-pass laying spacing d is 5mm, the rotation speed is 700rpm, and the forward speed is 150mm / min.

[0028] In addition, reference Figure 2 It can be seen that the adjacent layers are rotated at a certain angle, and the edge of the specimen is filled with a wide contour. The contour width is A, and A needs to fully cover all interface areas. Finally, the model is exported to a file format that can be recognized by the device. Figure 3 , the substrate is distributed nonlinearly in the filling path, and the passes are closely arranged; the edge of the repair area ( Figure 2The filling angle between adjacent layers changes. In this embodiment, the preferred method is to increase the filling angle by 63°. Figure 2 , the nth layer and the n+1th layer rotate 63° successively. Finally, a file format that can be recognized by the device is generated, which contains parameters and path planning.

[0029] Step S3: Determine the repair manufacturing process parameters; The formability of low heat input weak anisotropy repair of high-strength aluminum alloy friction stir weld defects mainly depends on the high-strength fusion between the filler area organization and the matrix with low energy input. Low heat input is first used for material supplementation. In this process 1, no metallurgical and mechanical bonding is generated between the filling material layers and the paths and between the filling and supplementary areas and the substrate. In process 1, in order to break through the directional heat transfer and single interface effect, the adjacent layers of the filler area are rotated 63° clockwise, and a non-linear close-packed filling method is used between the single layers to introduce a multi-interface effect. Then, in process 2, a repair tool with a serrated feature on the side is used to homogenize the tissue modifier to increase the metallurgical bonding and mechanical locking effect between the layers, paths and repair areas of the repair area and the substrate. The heat input in process 1 is less than that in process 2, but the heat input in process 2 is less than the heat introduced by filler methods such as melting welding. In addition, the repair process parameters are determined according to the above material system and manufacturing requirements.

[0030] For example, when selecting an appropriate material system, 2195 high-strength aluminum-lithium alloy is selected as the substrate, and the stir friction welding weld has serious thinning defects. In process 1, continuous water cooling is used to maintain the filler temperature at 150-250°C. This process only produces surface adhesion, and no metallurgical bonding and mechanical locking are produced. In process 2, the optimized combination of optimized repair tools, rotation speed, forward speed, etc. is selected to make the organizational optimization temperature at 400-450°C. In this process, obvious metallurgical bonding and mechanical locking are produced between the layers, between the passes, and between the filling area and the substrate.

[0031] The repair manufacturing process parameters include: the filling process temperature is in the range of 150 to 250°C, the tissue denaturation process temperature range is in the range of 400 to 450°C, the substrate is continuously water-cooled, the filling process temperature is in the range of 150 to 250°C, the tissue denaturation process temperature range is in the range of 400 to 450°C, the material filling single layer thickness t is 2.5mm, the movement spacing h between adjacent passes of the machine head is 5mm, the clockwise rotation angle between adjacent layers is 63°, the repair tool rotation speed is 700rpm, and the forward speed is 200mm / min.

[0032] Step S4: Data model processing, importing the data model containing the contour of the area to be repaired, the number of filling layers and the number of filling passes per layer into the model processing software in a file format, completing the repair model processing according to the repair manufacturing process parameters, and obtaining the processed repair model. Specifically, the three-dimensional format file generated in step S2 is imported into the additive manufacturing slice layer model processing software, according to the repair manufacturing parameters determined in step S3, t is the single layer thickness, d is the single pass laying spacing, and then the manufacturing path is planned according to the contour of the area to be repaired, and a defect repair command file of a single layer of non-linear densely distributed substrate filling path is generated.

[0033] Step S5: According to the repair manufacturing process parameters and the path planned in step S4, the tool of the additive repair equipment is matched to prepare the repaired high-strength aluminum alloy component. Continuous non-linear laying is performed in the area to be repaired, so that the continuous passes are distributed across the non-truncated interface, and the repair tool with a serrated structure on the circumference is used to fill and modify the repair area. The repair tool with a serrated structure on the edge improves the heat generation uniformity and material exchange efficiency between layers and paths, increases the bonding strength between layers and paths, eliminates various anisotropies, and prepares a weakly anisotropic area to be repaired with multiple cross-interfaces. The file format generated in step S3 is imported into the equipment, and through the motion coordination between the head and the turntable of the multi-axis linkage equipment, a repair tool with a serrated structure on the circumference is used to fill and modify the repair area. The repair tool with a serrated structure on the edge improves the heat generation uniformity and material exchange efficiency between layers and paths, increases the bonding strength between layers and paths, and eliminates various anisotropies. Finally, a high-strength aluminum alloy repaired part with low heat input and weak anisotropy is prepared. Set the equipment parameters and import the file generated in step S4 into the equipment so that the direction of the first layer of filling material is parallel to the +X direction of the equipment and the second layer is +X offset by +Y 63°. Finally, a repaired high-strength aluminum alloy component with low heat input and weak anisotropy is prepared.

[0034] The present invention adopts a method of increasing the repair area by a low heat input filler method and realizing the organization modification by heat material exchange, wherein the filling material is in a nonlinear close-packed distribution form, so that the filling area replaces the original single interface form according to the multi-interface effect, so that multiple contacts are formed between the filling area passes, and finally a repaired high-strength aluminum alloy component with weak anisotropy between the repair area and the substrate is obtained. High-strength aluminum alloys include 2195, 7075, etc. with high thermal crack sensitivity. Among them, the added material is filled in the area to be repaired in a poorly distributed manner to avoid the obvious anisotropy caused by the single interface formed by the layered or single linear distribution, so that multiple contacts are formed between the continuous filled area and the filling material, and finally a weak anisotropic additive repair area with geothermal input is obtained. The XY direction tensile strength of the repaired high-strength aluminum alloy component is 410Mpa, the Z direction tensile strength is 365Mpa, and the anisotropic strength difference is reduced to 10.97%. The matrix material includes one or more of 2195 aluminum-lithium alloy, 6061 aluminum alloy, 7075 aluminum alloy, 2219 aluminum alloy, and 2050 aluminum alloy. The matrix material is the main body of the repaired component.

[0035] In this embodiment, the tensile strength of the 2195 aluminum-lithium alloy parts repaired by the traditional melting welding filler method + traditional stir friction structure modification technology is 310Mpa in the XY direction and 220Mpa in the Z direction; the tensile strength of the sample prepared by the present invention is 410Mpa in the XY direction and 365Mpa in the Z direction. The anisotropic strength difference is reduced from the original 29.03% to 10.97%.

[0036] The substrate of the present invention adopts a nonlinear filling method with low energy input, which can effectively reduce heat input while weakening directional heat transfer, reduce single interface effects, and effectively weaken the anisotropy of the material. A tool with a sawtooth structure is used for tissue denaturation to increase the material and heat transfer between a single pass and a single layer, forming a high-strength interface with both mechanical locking and metallurgical bonding. At the same time, the nonlinear material filling method can achieve multi-point stable contact between adjacent passes and between the filling area and the substrate, forming a good bonding interface, and the anisotropy of the filling area in the XY and Z directions and between the filling area and the matrix is ​​improved. Combined with the angle rotation of 63° between adjacent layers, the formation of a single texture is improved, which can effectively improve the anisotropy of the workpiece.

[0037] The present invention aims to achieve the simultaneous filling and repair of the defects of the high-strength aluminum alloy thinning, excavation and other short-material welds, and involves a low heat input filling method for the defects of the high-strength aluminum alloy stir friction welds and anisotropic organization optimization methods. On the one hand, it solves the problem that the heat input of the high-strength aluminum alloy short-material repair filler is too high, which has a great impact on the performance of the substrate and the performance improvement is limited. On the other hand, it effectively weakens the anisotropy between the filling area and the substrate performance.

[0038] During the forming process of the parts of the present invention, the assembly of parts, parameter setting and other processes can be similar to the traditional stir friction welding method. The transition from stir friction welding to low-heat weld quality repair can be achieved by simply replacing the repair tool. Therefore, it can be repaired based on existing additive manufacturing equipment, tooling and production systems. However, unlike the prior art, this case uses a nonlinear close-packed filling method in the repair area to produce a multi-interface effect in the filling area, overcoming the problems of weak interlayer bonding and obvious anisotropy caused by a single interface effect. In addition, through the processing of the serrated steps around the repair tool, more material exchanges are generated between layers and channels, and between the repair area and the matrix. On the basis of forming a traditional welding metallurgical bond, an obvious mechanical locking effect is formed, thereby further improving the performance, thereby reducing the anisotropy of the repaired weld and component performance, and finally obtaining a high-strength aluminum alloy weld repair method with low heat input and a repaired stir friction weld that meets the standard requirements.

[0039] A high-strength aluminum alloy friction stir weld defect repair system provided by the present invention comprises: Module M1: Mark the area to be repaired and extract the outline of the area to be repaired; in the module M1, a three-dimensional model entity is established using computer-aided software according to the path and filling requirements of the repair tool, and the three-dimensional model entity is saved in a file format recognizable by the model processing software; the file format includes stl format and stp format.

[0040] Module M2: Calculate the filling passes and the number of layers according to the distribution of the area to be repaired, plan the multi-layer and multi-pass filling path of the cross-interface effect, and save it in a three-dimensional model that can be read by the device; the module M2 includes the extracted three-dimensional information of the area to be repaired, and calculates the filling passes and the number of layers according to the three-dimensional information; the three-dimensional information includes the size of the area to be repaired, the width of a single pass and the thickness of a single layer; the calculation formula for the number of filling layers and the number of filling passes per layer is as follows: N=(h+5) / t M=l or M=w / d Wherein, N represents the number of filling layers, M represents the number of filling passes in each layer, l, w, h represent the length, width, and height of the area to be repaired, respectively, d represents the width of a single layer, and t represents the thickness of a single layer.

[0041] Module M3: Determine the parameters of the repair manufacturing process; the module M3 includes the first process and the second process; the first process is to first use low heat input to supplement the material, at this time, there is no metallurgical and mechanical bonding between the filling material layers and the paths, and between the filling area and the base material, the adjacent layers of the filling area rotate 63° clockwise, and a non-linear close-packed filling method is used between the single layers to introduce a multi-interface effect; the second process is to use a repair tool with serrated features on the side to perform a uniform treatment of the tissue modifier, increase the metallurgical bonding and mechanical locking effect between the layers and paths of the repair area, and between the repair area and the base material. The heat input in the first process is less than that in the second process, and the heat input in the second process is less than the heat introduced by the melting welding filler method.

[0042] Module M4: Data model processing, importing the data model containing the contour of the area to be repaired, the number of filling layers and the filling passes of each layer into the model processing software in a file format, completing the repair model processing according to the repair manufacturing process parameters, and obtaining the filling and repair path of the part to be repaired; in the module M4, a nonlinear dense arrangement method is adopted in the single-layer pass of the filling area, and a wide contour filling method is adopted in the prepared filling area and the interface area of ​​the substrate to cover all interface areas. The module M4 includes importing the three-dimensional format file generated by module M2 into the additive manufacturing slice layered model processing software, and according to the repair manufacturing parameters determined by module M3, t is the single layer thickness, d is the single-pass laying spacing, and then planning the manufacturing path according to the contour of the area to be repaired, and generating a defect repair command file for the substrate filling path.

[0043] Module M5: According to the repair manufacturing process parameters and the path planned by module M4, the tools of the additive repair equipment are used to prepare the repaired high-strength aluminum alloy component. In the module M5, continuous non-linear laying is performed in the area to be repaired, so that the continuous passes are distributed at the intersection of non-truncated interfaces, and a repair tool with a circumferential serrated structure is used to fill and modify the repair area to prepare a weakly anisotropic area to be repaired with multiple intersection interfaces. A low-calorie filling method including stir friction additive is used, and the added material is filled in the area to be repaired in a poorly distributed manner, so that multiple contacts are formed between the continuous filled area and the filling material, and finally a low-heat input, weakly anisotropic, high-strength aluminum alloy repair area is obtained.

[0044] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for repairing defects in high-strength aluminum alloy friction stir welds, characterized in that: include: Step S1: Mark the area to be repaired and extract the outline of the area to be repaired; Step S2: Calculate the filling passes and the number of layers according to the distribution of the area to be repaired, plan the multi-layer and multi-pass filling paths of the cross-interface effect, and save them in a three-dimensional model that can be read by the device; Step S3: Determine repair manufacturing process parameters; Step S4: data model processing, importing the data model including the outline of the area to be repaired, the number of filling layers and the filling passes of each layer into the model processing software in a file format, completing the repair model processing according to the repair manufacturing process parameters, and obtaining the filling repair path of the part to be repaired; Step S5: preparing a repaired high-strength aluminum alloy component by cooperating with tools of the additive repair equipment according to the repair manufacturing process parameters and the path planned in step S4.

2. The high-strength aluminum alloy friction stir weld defect repair method according to claim 1, characterized in that: In the step S1, a three-dimensional model entity is established using computer-aided software according to the path and filling requirements of the repair tool, and the three-dimensional model entity is saved in a file format recognizable by the model processing software; The file formats include stl format and stp format.

3. The high-strength aluminum alloy friction stir weld defect repair method according to claim 1, characterized in that: The step S2 includes extracting three-dimensional information of the area to be repaired, and calculating the filling passes and the number of layers according to the three-dimensional information; The three-dimensional information includes the size of the area to be repaired, the width of a single pass, and the thickness of a single layer; The calculation formula for the number of filling layers and the number of filling passes per layer is as follows: N=(h+5) / t M=l or M=w / d Wherein, N represents the number of filling layers, M represents the number of filling passes in each layer, l, w, h represent the length, width, and height of the area to be repaired, respectively, d represents the width of a single layer, and t represents the thickness of a single layer.

4. The high-strength aluminum alloy friction stir weld defect repair method according to claim 1, characterized in that: The step S3 includes a first process and a second process; The first process is to first use low heat input to supplement the material. At this time, there is no metallurgical and mechanical bonding between the filling material layers and the channels, and between the filling and supplementing areas and the substrate. The adjacent layers in the filling area are rotated 63° clockwise, and a non-linear close-packed filling method is used between the single layers to introduce a multi-interface effect. The second process is to use a repair tool with serrated features on the side to perform a homogenization treatment on the tissue modifier, thereby increasing the metallurgical bonding and mechanical locking effect between layers and paths in the repair area and between the repair area and the substrate.

5. The high-strength aluminum alloy friction stir weld defect repair method according to claim 4, characterized in that: The heat input in the first process is less than that in the second process, and the heat input in the second process is less than the heat introduced by means of melting the welding filler.

6. The high-strength aluminum alloy friction stir weld defect repair method according to claim 1, characterized in that: In the step S4, a nonlinear dense arrangement is adopted in the single-layer pass of the filling area, and a wide contour filling method is adopted in the interface area between the prepared filling area and the substrate to cover all the interface areas.

7. The high-strength aluminum alloy friction stir weld defect repair method according to claim 1, characterized in that: The step S4 includes importing the three-dimensional format file generated in step S2 into the additive manufacturing slice layer model processing software, and according to the repair manufacturing parameters determined in step S3, t is the single layer thickness, d is the single lane laying spacing, and then planning the manufacturing path according to the contour of the area to be repaired, and generating a defect repair command file for the substrate filling path.

8. The high-strength aluminum alloy friction stir weld defect repair method according to claim 1, characterized in that: In step S5, continuous non-linear paving is performed in the area to be repaired, so that the continuous passes are distributed at intersecting non-truncated interfaces, and a repair tool with a circumferential sawtooth structure is used to fill and modify the repair area to prepare a weakly anisotropic area to be repaired with multiple intersecting interfaces.

9. The high-strength aluminum alloy friction stir weld defect repair method according to claim 8, characterized in that: A low-heat filling method including stir friction additive is adopted, and the added material is filled in the area to be repaired in a poorly distributed manner, so that multiple contacts are formed between the continuous filled area and the filling material, and finally a low heat input, weakly anisotropic, high-strength aluminum alloy repair area is obtained.

10. A high-strength aluminum alloy friction stir weld defect repair system, characterized in that: include: Module M1: Mark the area to be repaired and extract the contour of the area to be repaired; Module M2: Calculate the filling passes and the number of layers according to the distribution of the area to be repaired, plan the multi-layer and multi-pass filling paths of the cross-interface effect, and save them in a three-dimensional model that can be read by the device; Module M3: Determine the repair manufacturing process parameters; Module M4: data model processing, importing the data model containing the outline of the area to be repaired, the number of filling layers and the filling passes of each layer into the model processing software in a file format, completing the repair model processing according to the repair manufacturing process parameters, and obtaining the filling repair path of the part to be repaired; Module M5: According to the repair manufacturing process parameters and the path planned by module M4, the tools of the additive repair equipment are coordinated to prepare the repaired high-strength aluminum alloy component.

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