Scanning correction forming method and processing equipment for superconducting cavity workpiece

Abstract

According to the scanning correction forming method of the superconducting cavity workpiece and the machining equipment, after the niobium plate is punched for the first time, the obtained semi-finished product is subjected to three-dimensional scanning, and the step can accurately obtain structural data of the semi-finished product, including stress distribution and thickness change conditions; and then, according to the stress distribution data, calculating a stress concentration coefficient, if the stress concentration coefficient is too large, performing comprehensive annealing, and if the stress concentration coefficient is too small, performing local annealing on a high-stress region, releasing stress of a part of the region, and meanwhile, preventing crystal grains in other regions from growing, thereby ensuring the overall mechanical property and further ensuring the qualified rate of products. And then, finding out a first area with the minimum thinning effect of the niobium plate in the first stamping according to the thickness change data, and forming a positioning hole in the first area to serve as a positioning reference of a semi-finished product, so that the phenomenon of mechanical failure or superconducting performance reduction of a superconducting cavity workpiece of a finished product after long-term use is reduced, and the service life is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of superconducting cavity processing, and in particular to a scanning correction molding method and processing equipment for a superconducting cavity workpiece. Background Art With the in-depth development of modern physics, particle accelerator technology has become the core technology for research in many fields such as high-energy physics and nuclear physics. As a key component of a particle accelerator, the performance of a superconducting cavity directly determines the efficiency and effect of the accelerator; common superconducting cavities are usually made of niobium materials, because niobium has excellent superconducting properties in low-temperature environments. Combined with the resonance characteristics of the superconducting cavity, it can generate a high-intensity electromagnetic field to support particles to continuously obtain energy inside the cavity. In order to achieve stability and efficiency in a high-frequency working environment, the superconducting cavity must not only have excellent electromagnetic properties, but also have a high-precision shape and uniform surface quality to ensure the uniformity and stability of the electromagnetic field distribution.

[0002] Conventional superconducting cavity workpieces are mainly formed by single stamping or deep drawing, and after forming, they are partially corrected and polished to meet design requirements. Due to the low ductility of niobium, in the above-mentioned forming method, the niobium material will be subjected to great tensile force and deformation in a short period of time, especially in areas and edge positions with large curvature changes, which are prone to stress concentration. On the one hand, stress concentration will not only cause microcracks or uneven thickness during the stamping process, resulting in unqualified finished products, but also on the other hand, stress concentration will cause superconducting cavity workpieces to be more prone to mechanical failure or degradation of superconducting performance after long-term use, resulting in a short effective life of the finished product.

[0003] It can be seen that when the molding method in the prior art is applied to the scenario of preparing superconducting cavity workpieces with niobium materials, there are defects such as low qualified rate of finished products and short effective life. Summary of the invention

[0004] The object of the present invention is to provide a scanning correction forming method and processing equipment for a superconducting cavity workpiece, so as to solve the technical problems of low qualified product rate and short effective life in the prior art niobium superconducting cavity forming method.

[0005] To achieve this object, the present invention adopts the following technical solutions: A scanning correction forming method for a superconducting cavity workpiece, comprising: The niobium plate is punched for the first time to obtain a semi-finished product; Performing three-dimensional scanning on the semi-finished product to obtain a first three-dimensional model, and performing stress analysis and thickness analysis on the first three-dimensional model to obtain stress distribution data and thickness change data of the first three-dimensional model; The stress concentration factor is calculated based on the stress distribution data. The stress concentration factor reflects the ratio of the number of stress concentration points to the total number of nodes in the first three-dimensional model, and determines whether the stress concentration factor is greater than a preset stress standard factor C. If so, the semi-finished product is fully annealed; If not, the semi-finished product is subjected to local annealing; Acquire a first area of ​​the first three-dimensional model where the thickness is thinned the least according to the thickness variation data, use the first area as a positioning area for the semi-finished product, and open a positioning hole in the positioning area; Based on the positioning hole, the semi-finished product is punched for the second time to obtain a superconducting cavity workpiece, and the superconducting cavity workpiece is scanned in three dimensions to obtain a second three-dimensional model. The second three-dimensional model is compared with the three-dimensional design model to screen out qualified superconducting cavity workpieces.

[0006] Optionally, the three-dimensional scanning of the semi-finished product includes: Perform laser scanning and ultrasonic scanning on the semi-finished product respectively to obtain a three-dimensional point cloud data set and an ultrasonic data set; Through the ICP algorithm, the coordinate system of the ultrasonic data set is unified with the coordinate system of the 3D point cloud data set; Perform weighted fusion on the ultrasonic data set after coordinate system one and the three-dimensional point cloud data to obtain an aligned data set; The aligned data set is triangulated to obtain a first three-dimensional model including surface nodes and internal nodes.

[0007] Optionally, performing stress analysis on the first three-dimensional model includes: The first three-dimensional model is imported into the finite element analysis software, and after meshing, the stress of each surface node and each internal node is solved; Determine whether the stress of the surface nodes and internal nodes exceeds the material yield strength, and mark the surface nodes that exceed the material yield strength as surface stress concentration points, and mark the internal nodes that exceed the material yield strength as internal stress concentration points.

[0008] Optionally, the aligned data set includes a penetration depth value, and the performing stress analysis on the first three-dimensional model includes: According to the penetration depth value, the first three-dimensional model is deeply layered to obtain a multi-layered cutting model; Import each layer of the cut model into the finite element analysis software, and solve the stress after meshing; The slicing models with stress higher than the material yield strength are selected and imported into the finite element analysis software. After meshing, the stress is solved, and the nodes exceeding the material yield strength are selected and marked as stress concentration points; According to each stress concentration point and the corresponding penetration depth value, it is determined whether a concentrated stress area penetrating the first three-dimensional model is formed. If so, it is determined that the stress concentration coefficient is greater than the preset stress standard coefficient C.

[0009] Optionally, the first stamping of the niobium plate comprises: Providing a first stamping die, the first stamping die comprising a first lower die and a first upper die; Putting the niobium plate into a first stamping die for stamping to obtain a semi-finished product; The second stamping of the semi-finished product comprises: Providing a second stamping die, the second stamping die comprising a second lower die and a second upper die; placing the semi-finished product into a second stamping die for stamping to obtain a superconducting cavity workpiece; Among them, the first lower die is a concave die, and the first upper die is a convex die; the second lower die is a convex die, and the second upper die is a concave die.

[0010] Optionally, the second upper mold comprises an upper mold body with a mounting groove and a customized convex mold detachably mounted in the mounting groove; a positioning pin for inserting into the positioning hole is connected to the customized convex mold; The molding method of the customized male mold includes: Presetting an initial contour surface of the customized convex mold, the initial contour surface matches a non-working surface of a standard superconducting cavity workpiece; Corresponding to the first area, a second area is formed on the initial contour surface, and the second area forms a pin hole for installing a positioning pin.

[0011] Optionally, performing stress analysis on the first three-dimensional model further includes: Determine whether a concentrated stress region including only internal nodes and no surface nodes is formed; If not, jump to execute the step of calculating the stress concentration factor according to the stress distribution data; If so, based on the concentrated stress region that only includes internal nodes and does not include surface nodes, find the closest upper approximate stress region on the upper surface of the first three-dimensional model, and find the closest lower approximate stress region on the lower surface of the first three-dimensional model; Determine whether there is a misalignment between the upper approach stress area and the lower approach stress area; If it does not exist, jump to execute the step of calculating the stress concentration factor according to the stress distribution data; If it exists, the upper approach stress area and the lower approach stress area of ​​the semi-finished product are marked respectively according to the first three-dimensional model, the upper approach stress area and the lower approach stress; the upper approach stress area of ​​the semi-finished product is irradiated by the first laser, and the lower approach stress area of ​​the semi-finished product is irradiated by the second laser; Among them, the power of the first laser is positively correlated with the distance between the upper stress-approaching area and the corresponding concentrated stress area in a first manner, the power of the second laser is positively correlated with the distance between the lower stress-approaching area and the corresponding concentrated stress area in a second manner, and the ratio of the first positive correlation to the second positive correlation is the same.

[0012] Optionally, the comprehensive annealing of the semi-finished product comprises: The semi-finished product is immersed in liquid metal, which is heated to 450°C-500°C by electric current and then slowly cooled.

[0013] Optionally, the locally annealing the semi-finished product comprises: Marking stress concentration areas of the semi-finished product according to the first three-dimensional model and stress distribution data; The stress concentration area of ​​the semi-finished product is irradiated with a laser, heated to 450°C-500°C and then slowly cooled.

[0014] A processing device adopts the scanning correction forming method of the superconducting cavity workpiece as described above, comprising a stamping device and a scanning device, wherein the stamping device is detachably connected to a first stamping die or a second stamping die.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The scanning correction forming method and processing equipment of the superconducting cavity workpiece provided by the present invention performs three-dimensional scanning on the semi-finished product obtained after the first stamping of the niobium plate. This step can accurately obtain the structural data of the semi-finished product, including stress distribution data and thickness change data; then, the stress concentration coefficient is calculated according to the stress distribution data. If the stress concentration coefficient is too large, full annealing is performed to release the stress of the semi-finished product evenly. If the stress concentration coefficient is too small, local annealing is performed on the high stress area to release the stress of some areas while avoiding the growth of grains in other areas, thereby ensuring the overall mechanical properties and further ensuring the qualified rate of the product.

[0016] Next, the first area where the niobium plate has the least thinning effect in the first stamping is found through the thickness change data, and a positioning hole is opened in the first area to serve as the positioning reference of the semi-finished product, which can reduce the risk of generating new stress concentration points and reduce the mechanical failure or degradation of superconducting performance of the finished superconducting cavity workpiece after long-term use, thereby improving the service life. In summary, the superconducting cavity workpiece obtained by the scanning correction molding method and processing equipment of the superconducting cavity workpiece has the advantages of high pass rate and long effective life. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0019] Figure 1 A schematic flow chart of a scanning correction forming method for a superconducting cavity workpiece provided in an embodiment of the present invention; Figure 2 A schematic diagram of the first principle structure of a processing device provided by an embodiment of the present invention; Figure 3 A second schematic structural diagram of a processing device provided by an embodiment of the present invention; Illustration: 1. Upper die base; 2. Primary punch; 3. Positioning plate; 4. Primary die; 5. Positioning pin; 6. Customized punch; 7. Upper die body; 8. Secondary punch. DETAILED DESCRIPTION

[0020] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0022] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0023] An embodiment of the present invention provides a scanning correction forming method for a superconducting cavity workpiece, which is suitable for the forming process of a superconducting cavity workpiece, and is particularly suitable for the forming of a superconducting cavity workpiece made of a niobium plate. In this embodiment, the scanning correction forming method for the superconducting cavity workpiece is optimized, which is different from the stamping forming method in the prior art, so that the formed superconducting cavity workpiece has a higher pass rate and a longer effective life.

[0024] like Figure 1 As shown, the scanning correction forming method of the superconducting cavity workpiece provided by the present invention specifically includes: S100, punching the niobium plate for the first time to obtain a semi-finished product; S200, performing three-dimensional scanning on the semi-finished product to obtain a first three-dimensional model, and performing stress analysis and thickness analysis on the first three-dimensional model to obtain stress distribution data and thickness change data of the first three-dimensional model; The first three-dimensional model includes a plurality of surface nodes and a plurality of internal nodes, each of the surface nodes and the internal nodes includes coordinate values ​​on the x, y, and z axes, the stress distribution data is reflected as the stress value of each surface node and the internal node, and the thickness variation data is reflected as the surface node of the upper surface in the first three-dimensional model and the distance between the surface node of the lower surface; S300, calculating a stress concentration factor according to the stress distribution data, wherein the stress concentration factor reflects the ratio of the number of stress concentration points to the total number of nodes of the first three-dimensional model, and determining whether the stress concentration factor is greater than a preset stress standard factor C; Exemplarily, the surface nodes whose stress values ​​exceed the yield strength of the material can be regarded as stress concentration points; the total nodes are the total number of surface nodes, and the ratio of the number of stress concentration points to the total nodes is obtained, that is, the stress concentration coefficient is obtained, and the stress concentration coefficient is compared with the preset stress standard coefficient C (which can be set to 0.7 in this embodiment) to determine whether the semi-finished product is suitable for full annealing or partial annealing. The stress standard coefficient C depends on the size, shape, and processing technology of the superconducting cavity workpiece, and is not specifically limited in this embodiment. As another optional implementation, the internal nodes whose stress values ​​exceed the yield strength of the material can also be regarded as stress concentration points. Correspondingly, the total nodes are the total number of surface nodes and internal nodes. It can be understood that selecting stress concentration points only from surface nodes, or selecting stress concentration points from surface nodes and internal nodes, depends on the accuracy difference of the first three-dimensional model. If the accuracy of the internal nodes is high, the stress concentration points are selected from the surface nodes and the internal nodes. Otherwise, the stress concentration points are selected from only the surface nodes; S310: If yes, the semi-finished product is fully annealed; S320, if not, perform local annealing on the semi-finished product; That is, when the stress concentration phenomenon of the first three-dimensional model is more serious and the ratio of the number of stress concentration points to the total nodes is higher, the semi-finished product is fully annealed; otherwise, the semi-finished product is partially annealed according to the distribution of stress concentration points of the three-dimensional model; S400, obtaining a first area of ​​the first three-dimensional model where the thickness is thinned the least according to the thickness variation data, and using the first area as a positioning area for the semi-finished product, and opening a positioning hole in the positioning area; S500, using the positioning hole as a reference, performing a second stamping on the semi-finished product to obtain a superconducting cavity workpiece, performing a three-dimensional scan on the superconducting cavity workpiece to obtain a second three-dimensional model, comparing the second three-dimensional model with the three-dimensional design model, and screening to obtain a qualified superconducting cavity workpiece.

[0025] Specifically, the scanning correction forming method of the superconducting cavity workpiece in this embodiment, after the first stamping of the niobium plate, the obtained semi-finished product is three-dimensionally scanned. This step can accurately obtain the structural data of the semi-finished product, including stress distribution data and thickness change data; then, the stress concentration coefficient is calculated according to the stress distribution data. If the stress concentration coefficient is too large, the semi-finished product is fully annealed so that the stress of the semi-finished product can be evenly released. If the stress concentration coefficient is too small, the high stress area is locally annealed to release the stress of some areas while avoiding the growth of grains in other areas, thereby ensuring the overall mechanical properties and thus ensuring the qualified rate of the product. Then, the first area with the least thinning effect of the niobium plate in the first stamping is found through the thickness change data, and the positioning area of ​​the semi-finished product is found based on the first area. Then, a positioning hole is opened in the positioning area, which is used as the positioning reference of the semi-finished product, which can reduce the risk of generating new stress concentration points and reduce the mechanical failure or superconducting performance degradation of the finished superconducting cavity workpiece after long-term use, so as to improve the service life. In summary, the superconducting cavity workpiece obtained by the scanning correction forming method of the superconducting cavity workpiece has the advantages of high qualified rate and long effective life.

[0026] Further, in step S200, the step: performing a three-dimensional scan on the semi-finished product specifically includes: S211, respectively perform laser scanning and ultrasonic scanning on the semi-finished product to obtain a three-dimensional point cloud data set P laser and the ultrasonic dataset P ultrasound ; For example, a 3D point cloud dataset P laser is a set of three-dimensional coordinate points obtained by scanning the surface of the semi-finished product with a laser scanner. Each three-dimensional coordinate point is represented by (x i ,y i , z i ), i is the index of the three-dimensional coordinate point, that is, P laser ={(xi ,y i , z i )}; Ultrasonic dataset P ultrasound is the set of ultrasonic points obtained after the semi-finished product is detected by the ultrasonic sensor. Each ultrasonic point is recorded as (x j ,y j , z j ), j is the index of the ultrasonic point, that is, P ultrasound ={(x j ,y j , z j )}; S212, guiding the coordinate system of the ultrasonic data set to be unified with the coordinate system of the three-dimensional point cloud data set through an ICP algorithm (Iterative Closest Point algorithm); Among them, the ICP algorithm is a point cloud alignment algorithm used to align point cloud data in two different coordinate systems. By finding a coordinate transformation (including rotation matrix R and translation matrix T), the data of one point cloud is "moved" to the position of another point cloud, thereby minimizing the distance difference between the two. It can handle the differences caused by different sensors. Through the ICP algorithm, the ultrasonic data set P ultrasound The coordinate system will gradually "approach" the 3D point cloud data P laser The coordinate system of the two is consistent, which improves the spatial alignment accuracy of the two, so that they can be fused, analyzed or visualized in the same coordinate system.

[0027] S213, performing weighted fusion on the ultrasonic data set after coordinate system one and the three-dimensional point cloud data to obtain an aligned data set; In this step, corresponding weights are set according to the reliability, accuracy, expertise and other information of each data source. For example, when calculating surface nodes, a higher weight is given to the three-dimensional point cloud data, and when calculating internal nodes, a higher weight is given to the ultrasonic number. The final aligned data set contains three-dimensional coordinates (x, y, z). It can be understood that the three-dimensional coordinates in the aligned data set refer to the ultrasonic data and can more accurately reflect the changes in material stress inside the semi-finished product.

[0028] S214 , triangulating the aligned data set to obtain a first three-dimensional model including surface nodes and internal nodes.

[0029] As another optional implementation, in step S200, the step of performing a three-dimensional scan on the semi-finished product specifically includes: S221, laser scan the finished product to obtain a three-dimensional point cloud data set P laser ; 3D point cloud dataset P laseris a set of three-dimensional coordinate points obtained by scanning the surface of the semi-finished product with a laser scanner. Each three-dimensional coordinate point is represented by (x i ,y i , z i ), i is the index of the three-dimensional coordinate point, that is, P laser ={(x i ,y i , z i )}; S222. Triangulate the set of three-dimensional coordinate points to obtain a first three-dimensional model including surface nodes and internal nodes, wherein the internal nodes are formed based on the surface nodes. For example, a node on the upper surface and another node on the lower surface (only the coordinate z is different) are obtained, and multiple internal nodes are filled between the two nodes. Of course, other types of internal filling methods can also be used to obtain a first three-dimensional model including surface nodes and internal nodes. At this time, the internal nodes in the first three-dimensional model are evenly distributed.

[0030] Based on the above two implementations, in step S200, performing stress analysis on the first three-dimensional model includes: S231, importing the first three-dimensional model into finite element analysis software, and solving the stress of each surface node and each internal node after meshing; the finite element analysis software may be commonly used stress analysis software such as ANASY, which is not limited in this embodiment; S232. Determine whether the stress of the surface nodes and the internal nodes exceeds the material yield strength, and mark the surface nodes exceeding the material yield strength as surface stress concentration points, and mark the internal nodes exceeding the material yield strength as internal stress concentration points.

[0031] As a supplementary implementation, the aligned data set includes a penetration depth value, that is, the aligned data set contains (x, y, z, d), where d is the penetration depth value, indicating the depth position of the node in the semi-finished product.

[0032] In step S200, performing stress analysis on the first three-dimensional model includes: S241, depth stratifying the first three-dimensional model according to the penetration depth value to obtain a multi-layer cutting model; for example, all coordinates with d of 0 to 1 are divided into a layer of cutting model, all coordinates with d of 1 to 2 are divided into a layer of cutting model, and so on; S242, importing each layer of the cut model into a finite element analysis software, and solving the stress after meshing; the finite element analysis software may be a commonly used stress analysis software such as ANASY, which is not limited in this embodiment; S243, select the cutting models with stress higher than the material yield strength, import them into the finite element analysis software, solve the stress after meshing, select the nodes exceeding the material yield strength and mark them as stress concentration points; Among them, steps S241-S243 introduce a depth layering method in stress analysis, and after the first three-dimensional model corresponding to the semi-finished product is cut according to the penetration depth value, a targeted finite element analysis is performed layer by layer. Since the semi-finished product is layered as a whole and has a thin wall thickness, stress concentration is prone to occur. The above method can more accurately identify stress concentration points that exceed the yield strength.

[0033] S244, according to each stress concentration point and the corresponding penetration depth value, determine whether a concentrated stress area is formed that penetrates the first three-dimensional model. If so, determine that the stress concentration coefficient is greater than the preset stress standard coefficient C. At the same time, jump to step S310 to perform comprehensive annealing on the semi-finished product; it can be understood that through the above method, it can be determined whether there is a stress concentration area extending from one surface to another surface of the semi-finished product. When there is such a concentrated stress area, it means that the superconducting cavity workpiece is at risk of fracture or overall deformation. Although the actual concentrated stress area is small at this time, in actual use, the concentrated stress area is equivalent to a plurality of dispersed and larger concentrated stress areas. Therefore, it is necessary to perform comprehensive annealing on the semi-finished product at this time to rearrange the grains inside the material, fully release the stress that penetrates the semi-finished product, and repair the microcracks and dislocations caused by processing stress, thereby significantly improving the uniformity and durability of the material. In addition, if not, execute step S300 and calculate the stress concentration coefficient according to the stress distribution data.

[0034] Based on the above implementation, the stress analysis of the first three-dimensional model further includes determining whether the first three-dimensional model includes a concentrated stress region completely located inside, exemplarily: Before step S244, the stress analysis of the first three-dimensional model further includes: S251, determining whether a concentrated stress region including only internal nodes and excluding surface nodes is formed; Through this step, the internal stress concentration points that are invisible on the surface of the semi-finished product can be effectively screened out. Compared with simple surface stress monitoring, this step finds out the internal stress concentration areas, which can reflect the internal stress conditions of the semi-finished product and provide a more targeted direction for subsequent analysis.

[0035] S252: If no, jump to step S244: calculate the stress concentration factor according to the stress distribution data; S253, if yes, then according to the concentrated stress area including only internal nodes and not surface nodes, find the closest upper approximate stress area on the upper surface of the first three-dimensional model, and find the closest lower approximate stress area on the lower surface of the first three-dimensional model; S254, determining whether there is a misalignment between the upper approach stress region and the lower approach stress region; By further judging the alignment between the upper and lower stress-approaching areas and the concentrated stress areas, potential risk areas can be accurately located. In the actual use of niobium superconducting cavity workpieces, local stress dislocation may cause uneven deformation or cracks inside the cavity, thereby affecting its superconducting performance at low temperatures. By judging the dislocation of the upper and lower stress-approaching areas, risk areas can be discovered and located in advance.

[0036] S255, if it does not exist, jump to step S244, calculate the stress concentration factor according to the stress distribution data; S256, if it exists, mark the upper approach stress area and the lower approach stress area of ​​the semi-finished product respectively according to the first three-dimensional model, the upper approach stress area and the lower approach stress area; irradiate the upper approach stress area of ​​the semi-finished product with a first laser, and irradiate the lower approach stress area of ​​the semi-finished product with a second laser; Among them, the power of the first laser is positively correlated with the distance between the upper approach stress area and the corresponding concentrated stress area, and the power of the second laser is positively correlated with the distance between the lower approach stress area and the corresponding concentrated stress area, and the ratio of the first positive correlation to the second positive correlation is the same. Through the above settings, the heat affected range of the laser can be effectively controlled to avoid damage to the surface of the superconducting cavity workpiece due to excessive laser power, and it can also ensure that the energy is concentrated on the dislocation stress area, thereby achieving precise internal stress adjustment. At the same time, since niobium materials have certain brittleness and are easily affected by excessive heat energy in thin-walled structures, by controlling the upper and lower laser powers, the above settings can effectively reduce the risk of secondary damage during the correction process, thereby better ensuring the structural integrity and superconducting properties of the workpiece. In addition, the power of the first laser and the second laser are positively correlated with the distance between the upper and lower approach stress areas and the concentrated stress areas, respectively, which can ensure that the annealing temperature evenly covers the entire dislocation stress area, thereby avoiding uneven stress recovery and generating new stress concentration points, and specifically releasing the stress of the concentrated stress area that only contains internal nodes and does not contain surface nodes.

[0037] On the basis of the above-mentioned implementation, the first stamping of the niobium plate in step S100 includes: S101, providing a first stamping die, wherein the first stamping die comprises a first lower die and a first upper die; S102, placing the niobium plate into a first stamping die for stamping to obtain a semi-finished product; In step S500, the second stamping of the semi-finished product includes: S521, providing a second stamping die, wherein the second stamping die comprises a second lower die and a second upper die; S522, placing the semi-finished product into a second stamping die for stamping to obtain a superconducting cavity workpiece; Among them, the first lower die is a concave die, and the first upper die is a convex die; the second lower die is a convex die, and the second upper die is a concave die. Among them, during the first stamping, the superconducting cavity side of the niobium plate is facing upward, which helps to form the main cavity shape and avoid excessive stress inside the cavity. In the second stamping, placing the cavity face down can disperse the stress during the forming process, especially around the cavity and in areas with large curvature, thereby reducing the probability of occurrence of stress concentration areas and improving the structural stability of the workpiece. In addition, during stamping, areas with large changes in cavity curvature are prone to thickness thinning. Stamping in different directions can compensate for the thickness change to a certain extent between the two processes, so that the wall thickness of the superconducting cavity after forming is more uniform to meet the design requirements.

[0038] like Figure 2 As shown, the first lower die includes a primary die 4 and a positioning plate 3 installed on the primary die 4, and the first upper die includes an upper die holder 1 and a primary punch 2 installed on the upper die holder 1; the niobium plate is positioned on the primary die 4 by using the positioning plate 3, and the semi-finished product is formed by pressing down the upper die holder 1 and the primary punch 2.

[0039] like Figure 3 As shown, the second lower mold includes a secondary punch 8, and the second upper mold includes an upper mold body 7 with a mounting groove and a customized punch 6 detachably mounted in the mounting groove; a positioning pin 5 for inserting into a positioning hole is connected to the customized punch.

[0040] In step S500, the molding method of the customized male mold includes: S511, presetting an initial contour surface of the customized convex mold, wherein the initial contour surface matches a non-working surface of a standard superconducting cavity workpiece; S512, corresponding to the first area, forming a second area on the initial contour surface, and forming a pin hole for installing a positioning pin in the second area.

[0041] By presetting an initial contour surface that conforms to the non-working surface of a standard superconducting cavity workpiece and forming a locating pin hole on the contour surface, it is easy to insert the locating pin and ensure precise mold alignment, avoiding the risk of mold offset or displacement during the forming process, thereby ensuring the accuracy and consistency of the stamping process and further improving the processing accuracy.

[0042] On the basis of the above-mentioned implementation mode, the comprehensive annealing of the semi-finished product comprises: The semi-finished product is immersed in liquid metal, which is heated to 450°C-500°C by electric current and then slowly cooled.

[0043] Based on the above implementation, the local annealing of the semi-finished product includes: Marking stress concentration areas of the semi-finished product according to the first three-dimensional model and stress distribution data; The stress concentration area of ​​the semi-finished product is irradiated with a laser, heated to 450°C-500°C and then slowly cooled.

[0044] This embodiment also provides a processing device, characterized in that it adopts the scanning correction forming method of the superconducting cavity workpiece described above, including a stamping device and a scanning device, and the stamping device is detachably connected to the first stamping die or the second stamping die.

[0045] To facilitate understanding by those skilled in the art, the following embodiments are used as an introduction to the principles.

[0046] Embodiment 1: S100, punching the niobium plate for the first time to obtain a semi-finished product; S200, performing three-dimensional scanning on the semi-finished product to obtain a first three-dimensional model, and performing stress analysis and thickness analysis on the first three-dimensional model to obtain stress distribution data and thickness change data of the first three-dimensional model; Step S200 specifically includes: S221, laser scan the finished product to obtain a three-dimensional point cloud data set P laser ; 3D point cloud dataset P laser is a set of three-dimensional coordinate points obtained by scanning the surface of the semi-finished product with a laser scanner. Each three-dimensional coordinate point is represented by (x i ,y i , z i ), i is the index of the three-dimensional coordinate point, that is, P laser ={(x i ,y i , z i )}; S222, triangulating the three-dimensional coordinate point collection to obtain a first three-dimensional model including surface nodes and internal nodes; S231, importing the first three-dimensional model into finite element analysis software, and solving the stress of each surface node and each internal node after meshing; the finite element analysis software may be commonly used stress analysis software such as ANASY, which is not limited in this embodiment; S232, determining whether the stress of the surface nodes and the internal nodes exceeds the material yield strength, and marking the surface nodes exceeding the material yield strength as surface stress concentration points, and marking the internal nodes exceeding the material yield strength as internal stress concentration points; S300, calculating a stress concentration coefficient according to the stress distribution data, wherein the stress concentration coefficient reflects the ratio of the number of stress concentration points to the total nodes of the first three-dimensional model, and judging whether the stress concentration coefficient is greater than a preset stress standard coefficient C; at this time, the stress concentration coefficient is specifically the ratio of the number of surface stress concentration points to the number of surface nodes, reflecting the surface stress concentration of the semi-finished product; S310: If yes, the semi-finished product is fully annealed; S320, if not, perform local annealing on the semi-finished product; S400, obtaining a first area of ​​the first three-dimensional model where the thickness is thinned the least according to the thickness variation data, and using the first area as a positioning area for the semi-finished product, and opening a positioning hole in the positioning area; S500, using the positioning hole as a reference, performing a second stamping on the semi-finished product to obtain a superconducting cavity workpiece, performing a three-dimensional scan on the superconducting cavity workpiece to obtain a second three-dimensional model, comparing the second three-dimensional model with the three-dimensional design model, and screening to obtain a qualified superconducting cavity workpiece.

[0047] Embodiment 2: S100, punching the niobium plate for the first time to obtain a semi-finished product; S200, performing three-dimensional scanning on the semi-finished product to obtain a first three-dimensional model, and performing stress analysis and thickness analysis on the first three-dimensional model to obtain stress distribution data and thickness change data of the first three-dimensional model; Step S200 specifically includes: S211, respectively perform laser scanning and ultrasonic scanning on the semi-finished product to obtain a three-dimensional point cloud data set P laser and the ultrasonic dataset P ultrasound ; S212, guiding the coordinate system of the ultrasonic data set to be unified with the coordinate system of the three-dimensional point cloud data set through the ICP algorithm; S213, weighted fusion of the ultrasonic data set after coordinate system one and the three-dimensional point cloud data to obtain an aligned data set; the aligned data set includes three-dimensional coordinates (x, y, z) and a penetration depth value d; S214, triangulating the aligned data set to obtain a first three-dimensional model including surface nodes and internal nodes; S241, depth stratifying the first three-dimensional model according to the penetration depth value to obtain a multi-layer cutting model; for example, all coordinates with d of 0 to 1 are divided into a layer of cutting model, all coordinates with d of 1 to 2 are divided into a layer of cutting model, and so on; S242, importing each layer of the cut model into a finite element analysis software, and solving the stress after meshing; the finite element analysis software may be a commonly used stress analysis software such as ANASY, which is not limited in this embodiment; S243, select the cutting models with stress higher than the material yield strength, import them into the finite element analysis software, solve the stress after meshing, select the nodes exceeding the material yield strength and mark them as stress concentration points; S251, judging whether a concentrated stress region including only internal nodes and excluding surface nodes is formed according to each stress concentration point and the corresponding penetration depth value; S252: if not, jump to step S244 to determine whether a concentrated stress area is formed that penetrates the first three-dimensional model; S253, if yes, then according to the concentrated stress area including only internal nodes and not surface nodes, find the closest upper approximate stress area on the upper surface of the first three-dimensional model, and find the closest lower approximate stress area on the lower surface of the first three-dimensional model; S254, determining whether there is a misalignment between the upper approach stress region and the lower approach stress region; S255: If not, jump to step S244 to determine whether a concentrated stress area is formed that runs through the first three-dimensional model; S256, if it exists, mark the upper approach stress area and the lower approach stress area of ​​the semi-finished product respectively according to the first three-dimensional model, the upper approach stress area and the lower approach stress area; irradiate the upper approach stress area of ​​the semi-finished product with a first laser, and irradiate the lower approach stress area of ​​the semi-finished product with a second laser; S244, judging whether a concentrated stress region penetrating the first three-dimensional model is formed according to each stress concentration point and the corresponding penetration depth value, and if so, judging that the stress concentration coefficient is greater than the preset stress standard coefficient C. At the same time, skipping step S310, performing comprehensive annealing on the semi-finished product; S300, calculating a stress concentration coefficient according to the stress distribution data, wherein the stress concentration coefficient reflects the ratio of the number of stress concentration points to the total nodes of the first three-dimensional model, and judging whether the stress concentration coefficient is greater than a preset stress standard coefficient C; at this time, the stress concentration coefficient is specifically the ratio of the number of surface stress concentration points to the number of surface nodes, reflecting the surface stress concentration of the semi-finished product; S310: If yes, the semi-finished product is fully annealed; S320, if not, perform local annealing on the semi-finished product; S400, obtaining a first area of ​​the first three-dimensional model where the thickness is thinned the least according to the thickness variation data, and using the first area as a positioning area for the semi-finished product, and opening a positioning hole in the positioning area; S500, using the positioning hole as a reference, performing a second stamping on the semi-finished product to obtain a superconducting cavity workpiece, performing a three-dimensional scan on the superconducting cavity workpiece to obtain a second three-dimensional model, comparing the second three-dimensional model with the three-dimensional design model, and screening to obtain a qualified superconducting cavity workpiece.

[0048] It can be understood that, through steps S251 to S256, before executing the surface judgment step S300, the concentrated stress area inside the semi-finished product can be detected, and the internal concentrated stress area can be annealed first; then, by using steps S244 and S300, it is determined whether it is necessary to perform comprehensive annealing on the semi-finished product or to perform local annealing on the concentrated stress area on its surface, so as to ensure the quality of the superconducting cavity workpiece.

[0049] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A scanning correction molding method for a superconducting cavity workpiece, characterized in that: include: The niobium plate is punched for the first time to obtain a semi-finished product; Performing three-dimensional scanning on the semi-finished product to obtain a first three-dimensional model, and performing stress analysis and thickness analysis on the first three-dimensional model to obtain stress distribution data and thickness change data of the first three-dimensional model; The stress concentration factor is calculated based on the stress distribution data. The stress concentration factor reflects the ratio of the number of stress concentration points to the total number of nodes in the first three-dimensional model, and determines whether the stress concentration factor is greater than a preset stress standard factor C. If so, the semi-finished product is fully annealed; If not, the semi-finished product is subjected to local annealing; Acquire a first area of ​​the first three-dimensional model where the thickness is thinned the least according to the thickness variation data, use the first area as a positioning area for the semi-finished product, and open a positioning hole in the positioning area; Based on the positioning hole, the semi-finished product is punched for the second time to obtain a superconducting cavity workpiece, and the superconducting cavity workpiece is scanned in three dimensions to obtain a second three-dimensional model. The second three-dimensional model is compared with the three-dimensional design model to screen out qualified superconducting cavity workpieces.

2. The scanning correction forming method of a superconducting cavity workpiece according to claim 1, characterized in that: The three-dimensional scanning of the semi-finished product comprises: Perform laser scanning and ultrasonic scanning on the semi-finished product respectively to obtain a three-dimensional point cloud data set and an ultrasonic data set; Through the ICP algorithm, the coordinate system of the ultrasonic data set is unified with the coordinate system of the 3D point cloud data set; Perform weighted fusion on the ultrasonic data set after coordinate system one and the three-dimensional point cloud data to obtain an aligned data set; The aligned data set is triangulated to obtain a first three-dimensional model including surface nodes and internal nodes.

3. The scanning correction forming method of a superconducting cavity workpiece according to claim 2, characterized in that: Stress analysis of the first 3D model includes: The first three-dimensional model is imported into the finite element analysis software, and after meshing, the stress of each surface node and each internal node is solved; Determine whether the stress of the surface nodes and the internal nodes exceeds the material yield strength, and mark the surface nodes that exceed the material yield strength as surface stress concentration points, and mark the internal nodes that exceed the material yield strength as internal stress concentration points.

4. The scanning correction forming method of a superconducting cavity workpiece according to claim 2, characterized in that: The aligned data set further includes a penetration depth value, and the performing stress analysis on the first three-dimensional model includes: According to the penetration depth value, the first three-dimensional model is deeply layered to obtain a multi-layered cutting model; Import each layer of the cut model into the finite element analysis software, and solve the stress after meshing; The slicing models with stress higher than the material yield strength are selected and imported into the finite element analysis software. After meshing, the stress is solved, and the nodes exceeding the material yield strength are selected and marked as stress concentration points; According to each stress concentration point and the corresponding penetration depth value, it is determined whether a concentrated stress area penetrating the first three-dimensional model is formed. If so, it is determined that the stress concentration coefficient is greater than the preset stress standard coefficient C. If not, the stress concentration coefficient is obtained by calculating according to the stress distribution data.

5. The scanning correction forming method of a superconducting cavity workpiece according to claim 4, characterized in that: The first stamping of the niobium plate comprises: Providing a first stamping die, the first stamping die comprising a first lower die and a first upper die; Putting the niobium plate into a first stamping die for stamping to obtain a semi-finished product; The second stamping of the semi-finished product comprises: Providing a second stamping die, the second stamping die comprising a second lower die and a second upper die; placing the semi-finished product into a second stamping die for stamping to obtain a superconducting cavity workpiece; Among them, the first lower die is a concave die, and the first upper die is a convex die; the second lower die is a convex die, and the second upper die is a concave die.

6. The scanning correction forming method of a superconducting cavity workpiece according to claim 5, characterized in that: The second upper mold comprises an upper mold body with an installation groove and a customized convex mold detachably installed in the installation groove; a positioning pin for inserting into the positioning hole is connected to the customized convex mold; The molding method of the customized male mold includes: Presetting an initial contour surface of the customized convex mold, the initial contour surface matches a non-working surface of a standard superconducting cavity workpiece; Corresponding to the first area, a second area is formed on the initial contour surface, and the second area forms a pin hole for installing a positioning pin.

7. The scanning correction forming method of a superconducting cavity workpiece according to claim 4, characterized in that: The performing stress analysis on the first three-dimensional model further comprises: According to each stress concentration point and the corresponding penetration depth value, it is determined whether a concentrated stress area including only internal nodes and excluding surface nodes is formed; If not, jump to executing the step of determining whether a concentrated stress region penetrating the first three-dimensional model is formed; If so, based on the concentrated stress region that only includes internal nodes and does not include surface nodes, find the closest upper approximate stress region on the upper surface of the first three-dimensional model, and find the closest lower approximate stress region on the lower surface of the first three-dimensional model; Determine whether there is a misalignment between the upper approach stress area and the lower approach stress area; If not, jump to executing the step of determining whether a concentrated stress area penetrating the first three-dimensional model is formed; If it exists, the upper approach stress area and the lower approach stress area of ​​the semi-finished product are marked respectively according to the first three-dimensional model, the upper approach stress area and the lower approach stress; the upper approach stress area of ​​the semi-finished product is irradiated by the first laser, and the lower approach stress area of ​​the semi-finished product is irradiated by the second laser; Among them, the power of the first laser is positively correlated with the distance between the upper stress-approaching area and the corresponding concentrated stress area in a first manner, the power of the second laser is positively correlated with the distance between the lower stress-approaching area and the corresponding concentrated stress area in a second manner, and the ratio of the first positive correlation to the second positive correlation is the same.

8. The scanning correction forming method of a superconducting cavity workpiece according to claim 2, characterized in that: The comprehensive annealing of the semi-finished product comprises: The semi-finished product is immersed in liquid metal, which is heated to 450°C-500°C by electric current and then slowly cooled.

9. The scanning correction forming method of a superconducting cavity workpiece according to claim 2, characterized in that: The partial annealing of the semi-finished product comprises: Marking stress concentration areas of the semi-finished product according to the first three-dimensional model and stress distribution data; The stress concentration area of ​​the semi-finished product is irradiated with a laser, heated to 450°C-500°C and then slowly cooled.

10. A processing equipment, characterized in that: The scanning correction forming method of a superconducting cavity workpiece according to any one of claims 1 to 9 comprises a stamping device and a scanning device, wherein the stamping device is detachably connected to a first stamping die or a second stamping die.

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