A scanning correction forming method and processing equipment for superconducting cavity workpiece

Abstract

The present invention discloses a scanning, correction, and forming method and processing equipment for a superconducting cavity workpiece. After the first stamping of the niobium plate, a three-dimensional scan of the semi-finished product is performed. This step accurately obtains the structural data of the semi-finished product, including stress distribution and thickness variation. Next, the stress concentration factor is calculated based on the stress distribution data. If the stress concentration factor is too large, a full annealing is performed. If the stress concentration factor is too small, a local annealing is performed in the high-stress area, releasing stress in some areas while preventing grain growth in other areas, thereby ensuring overall mechanical properties and, in turn, the product's pass rate. Next, the thickness variation data is used to identify the first area of ​​the niobium plate where the thinning effect during the first stamping is minimal. A positioning hole is then opened in this first area, which serves as a positioning reference for the semi-finished product. This reduces the risk of mechanical failure or degradation of superconducting performance of the finished superconducting cavity workpiece after long-term use, thereby increasing its service life.

Description

Technical Field

[0001] The present invention relates to the field of superconducting cavity processing technology, and in particular to a scanning correction molding method and processing equipment for a superconducting cavity workpiece. Background Art

[0002] With the in-depth development of modern physics, particle accelerator technology has become a core technology in research in multiple fields, including 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 effectiveness of the accelerator. Common superconducting cavities are usually made of niobium, which 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, allowing particles to continuously gain energy within the cavity. To achieve stability and efficiency in high-frequency operating environments, the superconducting cavity must not only possess 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.

[0003] Conventional superconducting cavity workpieces are primarily formed through single stamping or deep drawing, followed by localized corrections and polishing to meet design requirements. Due to the low ductility of niobium, these forming methods subject the niobium material to significant tensile forces and deformation in a short period of time. This is particularly prone to stress concentration in areas with large curvature variations and at edges. This stress concentration can not only cause microcracks or uneven thickness during the stamping process, resulting in substandard finished products, but also makes the superconducting cavity workpiece more susceptible to mechanical failure or degradation of superconducting performance after long-term use, shortening the effective life of the finished product.

[0004] It can be seen that when the molding method in the prior art is applied to the scenario of preparing superconducting cavity workpieces from niobium materials, there are defects such as low finished product qualification rate and short effective life. Summary of the Invention

[0005] 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 finished product qualification rate and short effective life in the existing niobium superconducting cavity forming method.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A scanning correction forming method for a superconducting cavity workpiece, comprising:

[0008] Performing the first punching of the niobium plate to obtain a semi-finished product;

[0009] Performing a three-dimensional scan 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;

[0010] 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 it is determined whether the stress concentration factor is greater than the preset stress standard factor C.

[0011] If so, the semi-finished product is fully annealed;

[0012] If not, the semi-finished product is subjected to local annealing;

[0013] Obtaining a first region of the first three-dimensional model where the thickness reduction is the least based on the thickness variation data, using the first region as a positioning region for the semi-finished product, and opening a positioning hole in the positioning region;

[0014] Based on the positioning hole, the semi-finished product is punched a 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.

[0015] Optionally, performing three-dimensional scanning on the semi-finished product includes:

[0016] Perform laser scanning and ultrasonic scanning on the semi-finished product to obtain a 3D point cloud dataset and an ultrasonic dataset;

[0017] The ICP algorithm is used to unify the coordinate system of the ultrasonic dataset and the coordinate system of the 3D point cloud dataset.

[0018] Perform weighted fusion on the ultrasonic data set and the 3D point cloud data after coordinate system alignment to obtain an aligned data set;

[0019] The aligned data set is triangulated to obtain a first three-dimensional model including surface nodes and internal nodes.

[0020] Optionally, performing stress analysis on the first three-dimensional model includes:

[0021] Import the first three-dimensional model into the finite element analysis software, and after meshing, solve the stress of each surface node and each internal node;

[0022] 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.

[0023] Optionally, the aligned data set includes a penetration depth value, and the performing stress analysis on the first three-dimensional model includes:

[0024] According to the penetration depth value, the first three-dimensional model is depth-stratified to obtain a multi-layer segmented model;

[0025] Import each layer of the cut model into the finite element analysis software, mesh it, and solve the stress;

[0026] 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 that exceed the material yield strength and mark them as stress concentration points;

[0027] According to each stress concentration point and the corresponding penetration depth value, it is determined whether a concentrated stress area is formed that penetrates the first three-dimensional model. If so, it is determined that the stress concentration coefficient is greater than a preset stress standard coefficient C.

[0028] Optionally, the first punching of the niobium plate comprises:

[0029] Providing a first stamping die, the first stamping die comprising a first lower die and a first upper die;

[0030] placing the niobium plate into a first stamping die for stamping to obtain a semi-finished product;

[0031] The second stamping of the semi-finished product comprises:

[0032] Providing a second stamping die, the second stamping die comprising a second lower die and a second upper die;

[0033] placing the semi-finished product into a second stamping die for stamping to obtain a superconducting cavity workpiece;

[0034] Wherein, 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.

[0035] Optionally, the second upper mold includes an upper mold body with a mounting groove and a customized convex mold detachably mounted in the mounting groove; the customized convex mold is connected to a positioning pin for inserting into the positioning hole;

[0036] The molding method of the customized convex mold includes:

[0037] 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;

[0038] 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.

[0039] Optionally, performing stress analysis on the first three-dimensional model further includes:

[0040] Determine whether a concentrated stress region is formed that includes only internal nodes and no surface nodes;

[0041] If not, jump to the step of calculating the stress concentration factor according to the stress distribution data;

[0042] 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;

[0043] Determine whether there is a misalignment between the upper approach stress area and the lower approach stress area;

[0044] If it does not exist, jump to the step of calculating the stress concentration factor according to the stress distribution data;

[0045] 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 a first laser, and the lower approach stress area of ​​the semi-finished product is irradiated by a second laser;

[0046] 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.

[0047] Optionally, the comprehensive annealing of the semi-finished product includes:

[0048] The semi-finished product is immersed in liquid metal, which is heated to 450°C-500°C by electric current and then slowly cooled.

[0049] Optionally, the locally annealing the semi-finished product includes:

[0050] Marking stress concentration areas of the semi-finished product based on the first three-dimensional model and stress distribution data;

[0051] The stress concentration area of ​​the semi-finished product is irradiated with a laser, heated to 450°C-500°C and then slowly cooled.

[0052] 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.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] The scanning correction forming method and processing equipment for a superconducting cavity workpiece provided by the present invention perform a three-dimensional scan 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 variation data. Next, the stress concentration factor is calculated based on the stress distribution data. If the stress concentration factor is too large, full annealing is performed to uniformly release the stress of the semi-finished product. If the stress concentration factor is too small, local annealing is performed in high-stress areas to release the stress in some areas while preventing grain growth in other areas, thereby ensuring the overall mechanical properties and, in turn, the product qualification rate.

[0055] Next, the thickness variation data is used to identify the first area of ​​the niobium plate where the thinning effect during the first stamping is minimized. Positioning holes are then opened in this area, serving as a positioning reference for the semi-finished product. This reduces the risk of new stress concentration points and reduces the risk of mechanical failure or degradation of superconducting performance after long-term use in the finished superconducting cavity workpiece, thereby extending its service life. In summary, the superconducting cavity workpieces obtained using this scanning, correction, and forming method and processing equipment exhibit a high pass rate and a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0057] The structures, proportions, sizes, etc. depicted 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 intended to limit the conditions under which the present invention can be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and objectives that can be achieved by the present invention.

[0058] 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;

[0059] Figure 2 A schematic diagram of the first principle structure of a processing device provided in an embodiment of the present invention;

[0060] Figure 3 A schematic diagram of a second principle structure of a processing device provided in an embodiment of the present invention;

[0061] Illustration: 1. Upper die base; 2. Primary punch; 3. Locating plate; 4. Primary die; 5. Locating pin; 6. Customized punch; 7. Upper die body; 8. Secondary punch. DETAILED DESCRIPTION

[0062] 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 making creative work are within the scope of protection of the present invention.

[0063] In the description of the present invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on 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 located component.

[0064] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0065] 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 niobium plate. In this embodiment, by optimizing the scanning correction forming method of the superconducting cavity workpiece, which is different from the stamping forming method in the prior art, the formed superconducting cavity workpiece has a higher pass rate and a longer effective life.

[0066] like Figure 1 As shown, the scanning correction forming method of the superconducting cavity workpiece provided by the present invention specifically includes:

[0067] S100, performing the first punching of the niobium plate to obtain a semi-finished product;

[0068] S200, performing a three-dimensional scan 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 variation data of the first three-dimensional model;

[0069] The first three-dimensional model includes a plurality of surface nodes and a plurality of internal nodes, each of which 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 internal node. The thickness variation data is reflected as the distance between the surface nodes of the upper surface and the surface nodes of the lower surface in the first three-dimensional model.

[0070] S300, calculating a stress concentration factor based on the stress distribution data, where 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 determining whether the stress concentration factor is greater than a preset stress standard factor C;

[0071] For example, surface nodes whose stress values ​​exceed the material's yield strength can be considered stress concentration points. The total number of surface nodes is the total number of surface nodes. The ratio of the number of stress concentration points to the total number of nodes is calculated to determine the stress concentration coefficient. This stress concentration coefficient is compared with a 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, internal nodes whose stress values ​​exceed the material's yield strength can also be considered stress concentration points. Correspondingly, the total number of nodes is the total number of surface nodes and internal nodes. It will be understood that whether stress concentration points are selected only from surface nodes or from both surface and internal nodes depends on the accuracy of the first three-dimensional model. If the internal nodes are more accurate, stress concentration points are selected from both surface and internal nodes; otherwise, stress concentration points are selected only from surface nodes.

[0072] S310: If yes, perform comprehensive annealing on the semi-finished product;

[0073] S320: If not, perform local annealing on the semi-finished product;

[0074] 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 high, the semi-finished product is fully annealed; otherwise, the semi-finished product is partially annealed according to the distribution of stress concentration points in the three-dimensional model;

[0075] S400, obtaining a first region of the first three-dimensional model where the thickness is least reduced based on the thickness variation data, using the first region as a positioning region for the semi-finished product, and opening positioning holes in the positioning region;

[0076] S500 , performing a second punching on the semi-finished product based on the positioning hole 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.

[0077] Specifically, the scanning correction forming method of the superconducting cavity workpiece in this embodiment is to perform a three-dimensional scanning on the semi-finished product 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 variation data; then, the stress concentration coefficient is calculated based on the stress distribution data. If the stress concentration coefficient is too large, the entire semi-finished product is annealed to evenly release the stress of the semi-finished product; if the stress concentration coefficient is too small, the high stress area is locally annealed to release the stress in some areas while preventing the grain growth in other areas, thereby ensuring the overall mechanical properties and thus ensuring the qualified rate of the product. Then, the first area where the thinning effect of the niobium plate is the least in the first stamping is found by using the thickness variation data, and the positioning area of ​​the semi-finished product is found based on this first area. Then, a positioning hole is opened in the positioning area, which serves 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, thereby improving 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.

[0078] Furthermore, in step S200, the step of performing a three-dimensional scan on the semi-finished product specifically includes:

[0079] 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 ultrasound dataset P ultrasound ;

[0080] 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 ={(x i ,y i , z i )}; Ultrasonic dataset P ultrasound The ultrasonic point set is 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 )};

[0081] S212, guiding the coordinate system of the ultrasonic dataset to be unified with the coordinate system of the three-dimensional point cloud dataset through an ICP algorithm (Iterative Closest Point algorithm);

[0082] 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 the rotation matrix R and the 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.

[0083] 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;

[0084] In this step, corresponding weights are set based on 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 data. The final aligned dataset contains three-dimensional coordinates (x, y, z). It can be understood that the three-dimensional coordinates in the aligned dataset refer to the ultrasonic data and can more accurately reflect the material stress changes inside the semi-finished product.

[0085] S214 , performing triangulation on the aligned data set to obtain a first three-dimensional model including surface nodes and internal nodes.

[0086] As another optional embodiment, in step S200, the step of performing a three-dimensional scan on the semi-finished product specifically includes:

[0087] 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 )};

[0088] 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 as long as a first three-dimensional model including surface nodes and internal nodes is obtained. At this time, the internal nodes in the first three-dimensional model are evenly distributed.

[0089] Based on the above two embodiments, in step S200, performing stress analysis on the first three-dimensional model includes:

[0090] S231. Import the first three-dimensional model into finite element analysis software, mesh it, and solve the stress of each surface node and each internal node. The finite element analysis software can be commonly used stress analysis software such as ANASY, and is not limited in this embodiment.

[0091] S232. 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.

[0092] As a supplementary implementation, the aligned data set includes a penetration depth value, that is, the aligned data set includes (x, y, z, d), where d is the penetration depth value, indicating the depth position of the node in the semi-finished product.

[0093] In step S200, performing stress analysis on the first three-dimensional model includes:

[0094] S241. Depth-slicing the first three-dimensional model according to the penetration depth value to obtain a multi-layered cut model; for example, all coordinates with d between 0 and 1 are divided into a layer of cut models, all coordinates with d between 1 and 2 are divided into a layer of cut models, and so on;

[0095] S242, importing each layer of the cut model into finite element analysis software, meshing it, and solving the stress; the finite element analysis software can be commonly used stress analysis software such as ANASY, which is not limited in this embodiment;

[0096] S243. Select the segmented models with stresses higher than the material yield strength, import them into finite element analysis software, mesh them, solve the stresses, select the nodes that exceed the material yield strength, and mark them as stress concentration points;

[0097] Steps S241-S243 incorporate a depth-layered approach during stress analysis. The first 3D model corresponding to the semi-finished product is segmented based on the penetration depth, and targeted finite element analysis is performed layer by layer. Because the semi-finished product is layered and thin, stress concentration is prone to occur. This approach more accurately identifies stress concentration points exceeding the yield strength.

[0098] S244: Based on the stress concentration points and the corresponding penetration depth values, determine whether a concentrated stress region 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 and perform comprehensive annealing on the semi-finished product. It can be understood that the above method can determine whether the semi-finished product has a stress concentration region extending from one surface to the other. When such a concentrated stress region exists, it means that the superconducting cavity workpiece is at risk of fracture or overall deformation. Although the actual concentrated stress region is small, in actual use, this concentrated stress region is equivalent to multiple dispersed and larger concentrated stress regions. Therefore, it is necessary to perform comprehensive annealing on the semi-finished product to rearrange the grains within the material, fully release the stress that penetrates the semi-finished product, and repair microcracks and dislocations caused by processing stress, thereby significantly improving the uniformity and durability of the material. If not, execute step S300 and calculate the stress concentration coefficient based on the stress distribution data.

[0099] Based on the above embodiment, the stress analysis of the first three-dimensional model further includes determining whether the first three-dimensional model includes a concentrated stress region located entirely inside. For example:

[0100] Before step S244, performing stress analysis on the first three-dimensional model further includes:

[0101] S251, determining whether a concentrated stress region including only internal nodes and excluding surface nodes is formed;

[0102] This step can effectively screen out internal stress concentration points that are invisible on the surface of the semi-finished product. Compared with simple surface stress monitoring, this step identifies 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.

[0103] S252: If not, jump to step S244 and calculate the stress concentration factor based on the stress distribution data;

[0104] S253: If yes, then based on the concentrated stress region that includes only internal nodes and no surface nodes, search for the closest upper approximate stress region on the upper surface of the first three-dimensional model, and search for the closest lower approximate stress region on the lower surface of the first three-dimensional model;

[0105] S254, determining whether there is a misalignment between the upper approach stress region and the lower approach stress region;

[0106] By further determining the alignment between the upper and lower stress-prone regions and the concentrated stress areas, potential risk areas can be accurately located. During actual use, localized stress misalignment in niobium superconducting cavity components can lead to uneven deformation or cracks within the cavity, thereby affecting its superconducting performance at low temperatures. By determining the misalignment between the upper and lower stress-prone regions, risk areas can be discovered and located in advance.

[0107] S255: If not, jump to step S244 and calculate the stress concentration factor based on the stress distribution data;

[0108] S256. If so, mark the upper approach stress region and the lower approach stress region of the semi-finished product according to the first three-dimensional model, the upper approach stress region, and the lower approach stress region; irradiate the upper approach stress region of the semi-finished product with a first laser and irradiate the lower approach stress region of the semi-finished product with a second laser;

[0109] The power of the first laser is positively correlated with the distance between the upper approach stress region and the corresponding concentrated stress region, while the power of the second laser is positively correlated with the distance between the lower approach stress region and the corresponding concentrated stress region. The ratio of the first positive correlation to the second positive correlation is the same. This arrangement effectively controls the heat-affected zone (HAZ) of the laser, preventing damage to the superconducting cavity workpiece surface due to excessive laser power. It also ensures that energy is concentrated in the dislocated stress region, thereby achieving precise internal stress adjustment. Furthermore, since niobium is brittle and highly susceptible to excessive heat energy in thin-walled structures, controlling the upper and lower laser powers effectively reduces the risk of secondary damage during the correction process, thereby better protecting the structural integrity and superconducting properties of the workpiece. Furthermore, the power of the first and second lasers are positively correlated with the distance between the upper and lower approach stress regions and the concentrated stress region, respectively. This ensures that the annealing temperature is uniformly distributed across the entire dislocated stress region, preventing uneven stress recovery and the generation of new stress concentration points. This allows for targeted stress relief in the concentrated stress region, which contains only internal nodes and no surface nodes.

[0110] Based on the above embodiment, the first stamping of the niobium plate in step S100 includes:

[0111] S101, providing a first stamping die, the first stamping die comprising a first lower die and a first upper die;

[0112] S102, placing the niobium plate into a first stamping die for stamping to obtain a semi-finished product;

[0113] In step S500, performing a second stamping on the semi-finished product includes:

[0114] S521, providing a second stamping die, the second stamping die including a second lower die and a second upper die;

[0115] S522, placing the semi-finished product into a second stamping die for stamping to obtain a superconducting cavity workpiece;

[0116] 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, the cavity is placed face down, which 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.

[0117] like Figure 2 As shown, the first lower die includes a primary die 4 and a positioning plate 3 mounted on the primary die 4, and the first upper die includes an upper die base 1 and a primary punch 2 mounted on the upper die base 1. The niobium plate is positioned on the primary die 4 using the positioning plate 3, and the semi-finished product is formed by pressing down the upper die base 1 and the primary punch 2.

[0118] 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 the positioning hole is connected to the customized punch.

[0119] In step S500, the method for forming the customized male mold includes:

[0120] S511, presetting an initial contour surface of the customized convex mold, where the initial contour surface matches a non-working surface of a standard superconducting cavity workpiece;

[0121] S512 , corresponding to the first area, forming a second area on the initial contour surface, wherein the second area forms a pin hole for installing a positioning pin.

[0122] By presetting an initial contour surface that conforms to the non-working surface of a standard superconducting cavity workpiece and forming locating pin holes on this contour surface, it is easy to insert the locating pins 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.

[0123] On the basis of the above embodiment, the comprehensive annealing of the semi-finished product includes:

[0124] The semi-finished product is immersed in liquid metal, which is heated to 450°C-500°C by electric current and then slowly cooled.

[0125] Based on the above embodiment, the partial annealing of the semi-finished product includes:

[0126] Marking stress concentration areas of the semi-finished product based on the first three-dimensional model and stress distribution data;

[0127] The stress concentration area of ​​the semi-finished product is irradiated with a laser, heated to 450°C-500°C and then slowly cooled.

[0128] 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.

[0129] To facilitate understanding by those skilled in the art, the following embodiments are used as an introduction to the principles.

[0130] Example 1:

[0131] S100, performing the first punching of the niobium plate to obtain a semi-finished product;

[0132] S200, performing a three-dimensional scan 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 variation data of the first three-dimensional model;

[0133] Step S200 specifically includes:

[0134] 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 )};

[0135] S222, triangulating the set of three-dimensional coordinate points to obtain a first three-dimensional model including surface nodes and internal nodes;

[0136] S231. Import the first three-dimensional model into finite element analysis software, mesh it, and solve the stress of each surface node and each internal node. The finite element analysis software can be commonly used stress analysis software such as ANASY, and is not limited in this embodiment.

[0137] S232. Determine whether the stresses at the surface nodes and the internal nodes exceed 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;

[0138] S300: Calculate a stress concentration factor 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 determine whether the stress concentration factor is greater than a preset stress standard factor C. In this case, the stress concentration factor 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.

[0139] S310: If yes, perform comprehensive annealing on the semi-finished product;

[0140] S320: If not, perform local annealing on the semi-finished product;

[0141] S400, obtaining a first region of the first three-dimensional model where the thickness is least reduced based on the thickness variation data, using the first region as a positioning region for the semi-finished product, and opening positioning holes in the positioning region;

[0142] S500 , performing a second punching on the semi-finished product based on the positioning hole 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.

[0143] Example 2:

[0144] S100, performing the first punching of the niobium plate to obtain a semi-finished product;

[0145] S200, performing a three-dimensional scan 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 variation data of the first three-dimensional model;

[0146] Step S200 specifically includes:

[0147] 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 ultrasound dataset P ultrasound ;

[0148] 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;

[0149] S213, performing weighted fusion on the ultrasonic data set after coordinate system alignment 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;

[0150] S214, triangulating the aligned data set to obtain a first three-dimensional model including surface nodes and internal nodes;

[0151] S241. Depth-slicing the first three-dimensional model according to the penetration depth value to obtain a multi-layered cut model; for example, all coordinates with d between 0 and 1 are divided into a layer of cut models, all coordinates with d between 1 and 2 are divided into a layer of cut models, and so on;

[0152] S242, importing each layer of the cut model into finite element analysis software, meshing it, and solving the stress; the finite element analysis software can be commonly used stress analysis software such as ANASY, which is not limited in this embodiment;

[0153] S243. Select the segmented models with stresses higher than the material yield strength, import them into finite element analysis software, mesh them, solve the stresses, select the nodes that exceed the material yield strength, and mark them as stress concentration points;

[0154] S251, judging whether a concentrated stress region including only internal nodes and excluding surface nodes is formed based on each stress concentration point and the corresponding penetration depth value;

[0155] S252: If not, jump to step S244 to determine whether a concentrated stress area is formed that penetrates the first three-dimensional model;

[0156] S253: If yes, then based on the concentrated stress region that includes only internal nodes and no surface nodes, search for the closest upper approximate stress region on the upper surface of the first three-dimensional model, and search for the closest lower approximate stress region on the lower surface of the first three-dimensional model;

[0157] S254, determining whether there is a misalignment between the upper approach stress region and the lower approach stress region;

[0158] S255: If not, jump to step S244 to determine whether a concentrated stress region is formed that penetrates the first three-dimensional model;

[0159] S256. If so, mark the upper approach stress region and the lower approach stress region of the semi-finished product according to the first three-dimensional model, the upper approach stress region, and the lower approach stress region; irradiate the upper approach stress region of the semi-finished product with a first laser and irradiate the lower approach stress region of the semi-finished product with a second laser;

[0160] S244: Based on the stress concentration points and the corresponding penetration depth values, determine whether a concentrated stress region 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 fully anneal the semi-finished product;

[0161] S300: Calculate a stress concentration factor 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 determine whether the stress concentration factor is greater than a preset stress standard factor C. In this case, the stress concentration factor 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.

[0162] S310: If yes, perform comprehensive annealing on the semi-finished product;

[0163] S320: If not, perform local annealing on the semi-finished product;

[0164] S400, obtaining a first region of the first three-dimensional model where the thickness is least reduced based on the thickness variation data, using the first region as a positioning region for the semi-finished product, and opening positioning holes in the positioning region;

[0165] S500 , performing a second punching on the semi-finished product based on the positioning hole 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.

[0166] 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 concentrated stress area inside can be annealed first; then, using steps S244 and S300, it is determined whether the semi-finished product needs to be fully annealed or whether the concentrated stress area on its surface needs to be locally annealed, thereby ensuring the quality of the superconducting cavity workpiece.

[0167] 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 above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can 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: Performing the first punching of the niobium plate to obtain a semi-finished product; Performing a three-dimensional scan 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 it is determined whether the stress concentration factor is greater than the 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; Obtaining a first region of the first three-dimensional model where the thickness reduction is the least based on the thickness variation data, using the first region as a positioning region for the semi-finished product, and opening a positioning hole in the positioning region; Based on the positioning hole, the semi-finished product is subjected to a second punching to obtain a superconducting cavity workpiece, and the superconducting cavity workpiece is subjected to a three-dimensional scanning 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; The three-dimensional scanning of the semi-finished product comprises: Perform laser scanning and ultrasonic scanning on the semi-finished product to obtain a 3D point cloud dataset and an ultrasonic dataset; 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 and the 3D point cloud data after coordinate system alignment to obtain an aligned data set; triangulating the aligned data set to obtain a first three-dimensional model including surface nodes and internal nodes; the aligned data set also includes a penetration depth value; The performing stress analysis on the first three-dimensional model includes: According to the penetration depth value, the first three-dimensional model is depth-stratified to obtain a multi-layer segmented model; Import each layer of the cut model into the finite element analysis software, mesh it, and solve the stress; 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 that exceed the material yield strength and mark them as stress concentration points; Based on each stress concentration point and the corresponding penetration depth value, it is determined whether a concentrated stress area containing only internal nodes and excluding surface nodes is formed; If not, jump to executing the step of determining whether a concentrated stress area is formed penetrating the first three-dimensional model; 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 is formed that penetrates the first three-dimensional model; 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 a first laser, and the lower approach stress area of ​​the semi-finished product is irradiated by a second laser; determining, based on each stress concentration point and the corresponding penetration depth value, whether a concentrated stress region penetrating the first three-dimensional model is formed; if so, determining that the stress concentration coefficient is greater than a preset stress standard coefficient C; if not, performing the calculation based on the stress distribution data to obtain the stress concentration coefficient; 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.

2. The scanning correction forming method of a superconducting cavity workpiece according to claim 1, characterized in that: Stress analysis of the first 3D model includes: Import the first three-dimensional model into the finite element analysis software, and after meshing, solve the stress of each surface node and each internal node; 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.

3. The scanning correction forming method of a superconducting cavity workpiece according to claim 2, characterized in that: The first punching of the niobium plate comprises: Providing a first stamping die, the first stamping die comprising a first lower die and a first upper die; placing 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; Wherein, 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.

4. The scanning correction forming method of a superconducting cavity workpiece according to claim 3, characterized in that: The second upper mold includes an upper mold body with a mounting groove and a customized convex mold detachably mounted in the mounting groove; the customized convex mold is connected to a positioning pin for inserting into a positioning hole; The molding method of the customized convex mold includes: 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; 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.

5. The scanning correction forming method of a superconducting cavity workpiece according to claim 1, 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 an electric current and then slowly cooled.

6. The scanning correction forming method of a superconducting cavity workpiece according to claim 1, characterized in that: The partial annealing of the semi-finished product comprises: Marking stress concentration areas of the semi-finished product based on 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.

7. A processing equipment, characterized in that, The scanning correction forming method of a superconducting cavity workpiece according to any one of claims 1 to 6 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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