In Situ CT of Clinch Points – Enhancing Interface Detectability Using Electroplated Patterns of Radiopaque Materials

In Situ CT of Clinch Points – Enhancing Interface Detectability Using Electroplated Patterns of Radiopaque Materials | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article In Situ CT of Clinch Points – Enhancing Interface Detectability Using Electroplated Patterns of Radiopaque Materials Daniel Köhler, Alrik Dargel, Juliane Troschitz, Maik Gude, Robert Kupfer This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6584984/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 17 Sep, 2025 Read the published version in Journal of Nondestructive Evaluation → Version 1 posted 9 You are reading this latest preprint version Abstract A clinch point’s quality is usually assessed using ex-situ destructive testing methods. These, however, are unable to detect phenomena immediately during the joining process. For instance, elastic deformations reverse and cracks close after unloading. In situ methods such as the force-displacement evaluation are used to investigate a clinching process, though deviations in the clinch point geometry cannot be derived with this method. To overcome these limitations, the clinching process can be investigated using in situ computed tomography (in situ CT) using tool materials suitable for X-ray investigation. When joining aluminum parts, the sheet-sheet interface is hardly visible. Earlier investigations showed that radiopaque materials can be applied between the joining parts to enhance the detectability of the sheet-sheet interface. However, the layers cause strong artefacts, break during the clinching process or change the clinch joint’s properties significantly. In this paper, a minimally invasive method to enhance the interface detectability is presented. First, the aluminum oxide layer is removed by etching. Second, the specimen is electroplated with copper or gold, respectively. In some cases, a mask is applied to create a cross-shaped plating pattern. Then, the plated specimen is clinched with a non-plated counterpart and the interface detectability is assessed in CT scans of the clinch points. It is shown that a copper plating of 2.6-4 µm can visualize some parts of the interface, while 7-9 µm is suitable to enhance the detectability of the sheet-sheet interface almost continuously. Clinching In situ computed tomography Non-destructive testing Interface visibility Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Introduction Lightweight design can benefit significantly from mechanical joining methods such as clinching, because different materials can be joined. The design of clinch points, however, often relies on the experience of clinch tool specialists [1] combined with iterative testing and tool adjustments [2]. Furthermore, the tool configuration is often tailored to a specific material-thickness combination [3]. To design clinching tools more effectively and adapt them more quickly to changing conditions, a better understanding of the phenomena occurring in the joining zone during both manufacturing and loading is required. Additionally, this understanding allows for more accurate validation of numerical models. Conventional investigation methods cannot capture all phenomena. For example, macroscopic analysis of the cross-section does not reflect the actual deformation and crack state during manufacturing, as spring-back effects during unloading and sample preparation can alter this state. Computed tomography (CT) enables a three-dimensional investigation without the destructive influence on the specimen. In situ CT of the clinching process, to add on, eliminates the effect of unloading, allowing for the detailed investigation of the chronological progression of phenomena throughout the process [4]. When clinching equal materials, the sheet-sheet interface is hardly visible in CT due to the absence of an air gap caused by high contact forces in the joining zone. This impedes the post-processing of the CT data necessary for validation of numerical models. Earlier investigations showed that layers of radiopaque material can be applied between the joining parts to enhance the detectability of the sheet-sheet interface [5]. However, the layers caused strong artefacts and wrinkled during the clinching process [5] or changed the clinch joint’s properties significantly [6]. In this paper, a minimally invasive method to enhance the interface detectability is evaluated. For this, the outer oxide layer of an aluminum sheet is removed by etching. Then the sheet is locally electroplated in the joining zone with copper (Cu) or with gold (Au) and clinched with a non-treated aluminum sheet. The resulting interfaces are CT scanned and qualitatively evaluated. Moreover, the geometrical properties are measured and a software-driven layer extraction of the joint is tested. In initial tests, the optimum plating thickness is figured out by electroplating the whole surface in contact varying the process durations and plating material. In subsequent tests, it is tested whether the enhanced interface visualization can also be achieved using a mask to create a locally confined plating pattern while reducing the impact on the joining process. Materials and Methods All parts of the circular aluminum sheet (⌀ 40 mm for full-surface plating, ⌀ 20 mm for pattern plating, t = 2 mm) which were not supposed to be electroplated are masked with blue flash tape in the joining zone (K7666 [1] ) and package tape for the rest of the sheet. In order to create a sufficient bonding between plating and substrate, it is necessary to remove the aluminum oxide layer off the specimen. Therefore, the surface is etched using a sodium hydroxide solution (NaOH 20 %) for 2 min (Figure 1 a). After that, the residual hydroxide is removed using distilled water and the specimen is Cu or Au electroplated (Figure 1 c. For this, the specimen is electrically contacted with a direct current source (cathode). For Cu plating, a Cu plate is used as an anode. Both, anode and cathode, are submerged into a highly saturated solution of copper sulfate and positioned at a distance of ca. 10 cm from each other (Figure 1 c). For gold plating, a stainless-steel plate is used as anode and a gold solution [2] (4 g / l) is used as electrolyte. According to Faraday's first law of electrolysis the amount of substance deposited or dissolved at an electrode during electrolysis is directly proportional to the quantity of electric charge passed through the electrolyte. Thus, with constant current, the mass of deposited copper can be calculated with In initial tests, the entire surface is electroplated with either Cu or Au. For subsequent tests, the Cu plating is applied only to a reduced area in the form of a cross pattern (“cross plating”). This approach aims to minimize the influence on the joint’s mechanical properties while still enabling interface detection in two cross-sections. The pattern is created using the blue masking tape with a cross-shaped cutout (0.5 mm line width, 20 mm diameter), as shown in Figure 1 b. Platings with target thicknesses from 2.5, 5, 10 and 20 µm are created (1 specimen per thickness). Based on Faraday's first law of electrolysis, these thicknesses are expected by adjusting the plating process duration, as outlined in Table 1. The actual plating thickness is measured thereafter. The electric current is set at 0.3 A for the whole surface copper plating and at 0.1 A for the whole surface gold and cross plating. In order to improve adhesion of gold on aluminum, a copper strike layer of 2 – 7 µm thickness is applied before gold platting. After clinching the plated with the non-plated specimen, the clinch point is CT scanned to evaluate the interface detectability. Table 1. Plating durations in min. Plating with copper strike layer thickness of 2 µm (*) and 5 – 9 µm (**). Coating method Electric current [A] Target layer thickness [µm] Coating duration [min] Actual layer thickness [µm] Cu layer 0.3 2.5 4.75 4 5 9.5 7 10 19 9 20 38 19 Cu strike 0.3 2.5 4.75 2 5 9.5 5 – 9 Au layer 0.1 1.25* 5 1 2.5** 9.9 1 5** 19.8 2 15** 59 5 Cu cross 0.1 2.5 3 2.6 5 6 6.6 10 9 9 20 20 19.7 The electric charge for each coating test and the resulting plating thickness can be seen in Figure 3. Notably, the relationship approximates a linear increase. While the steeper incline for the copper cross pattern can be explained with the reduced plating surface, the flat increase for Au plating indicates a lower process efficiency than copper plating. In Figure 2 a set of exemplarily selected specimens after electroplating is shown beside an aluminum sheet without plating for comparison. In (b) can be noticed, how the layer is more consistent at the edges (darker) and more porous in the center (brighter) resulting from the short electroplating duration. Otherwise, the layers appear uniform and consistent. In (c) the Impurities on the sample are probably due to diffusion of copper through the gold layer and subsequent oxidation of the copper. Also, the cross patterns show a clear edge. However, due to the manual cutting of the cross pattern cut out in the tape, the crosses deviate slightly from the center of the specimen. The plated specimen is clinched with a non-plated counterpart using the punch A50100[3] and the die BE8012[4] on a ZwickRoell 1465 testing machine (single-step, rotationally symmetric joint without cut section). A column frame is used to improve alignment of the tools (Figure 1 d). Thereafter, a stack of specimens is scanned in a single CT scan with helical trajectory applying the parameters shown in Table 2. Finally, the CT images are reconstructed using datos|x 2 rec[5] and evaluated in VG Studio Max 3.4[6] Table 2: CT parameters Parameter Unit Value Acceleration voltage [kV] 150 Tube current [µA] 100 Focal spot size [µm] 15 Voxel size [µm] 10 Physical filter [mm] 0.5 (Cu) Exposure time [ms] 500 Averaging 4 Skip 1 X-ray projections 2016 [1] Suter Kunststoffe AG, Aefligenstrasse 3, 3312 Fraubrunnen, Switzerland [2] Betzmann Galvanik, Am Berghof 20, 88630 Pfullendorf, Germany [3] TOX PRESSOTECHNIK GmbH & Co.KG, Weingarten, Germany [4] TOX PRESSOTECHNIK GmbH & Co.KG, Weingarten, Germany [5] Baker Hughes Company, 2001 Rankin Road, Houston, Texas 77073, USA [6] Volume Graphics GmbH, Speyerer Straße 4 – 6, 69115 Heidelberg, Germany Results and Discussion Figure 4 shows both the average maximum clinching force and the average residual bottom thickness, including standard deviations, for each plating method. The average forces are 7-8 % higher than in the reference clinching process (without contrast-enhancing layer). Since both the maximum clinching force and residual bottom thickness directly depend on the punch stroke, this factor must be taken into account. The reference clinching force resulted from a punch stroke of 5.43 mm, while the specimens with Cu and Cu strike and Au layers were clinched with slightly reduced punch stroke of 5.38 mm. The increased thickness of the stacked sheets to be joined and the higher friction resulting from the degreased plated surfaces led to an increase in both the maximum force and the residual bottom thickness. Adjusting the punch stroke to match the residual bottom thickness of the reference would have led to even higher forces. In the case of Cu cross specimens, the punch stroke was adapted to 5.54 mm to achieve a residual bottom thickness similar to the reference. Despite the reduced treatment surface for the cross-pattern plating, the clinching force remained 7 % higher than in the reference process. Figure 5 shows the CT cross-sections of the example specimens from Figure 2. Specimens with a Cu strike Au layer exhibit strong beam hardening artifacts (b, c), which hinder automatic interface detection. Additionally, the contrast material appears to alter the interface course in the bottom region of the joint (c). The specimen with a 4 µm Cu layer shows low interface visibility in the bottom region (d). However, air-filled gaps allow partial interface detection, enabling a volume segmentation with minor inaccuracies during post processing of the CT data. Increasing the Cu layer to 7 µm results in a nearly continuous presence of the contrast layer, with only slight accumulation in the undercut region (e). Specimens with cross plating with very low thickness show similar partial detectability in the bottom region (f). For thicker cross platings, the contrast material appears distorted along the bottom interface (g), likely due to insufficient adhesion and contact surface to the substrate aluminum sheet. To quantify the joint quality, geometrical properties were evaluated for all investigated plating methods, including full-surface Cu layer, Cu strike and Au layer, and Cu cross platings. Using the CT images, for each specimen, the undercut and neck thickness were measured on the left and right side in two sectional views oriented 90° apart. For the purpose of further analysis, the mean values from the set of four measurements were utilized. Additionally, the minimum residual base thickness was determined separately for the punch-side and the die-side. Therefore, the minimum distance from the interface to the surface of the punch-side respectively die side from both sectional views was measured. The results are summarized in Figure 6, which also indicates the ranges for undercut, neck thickness, and minimum residual base thickness of the reference specimen without plating. Across all specimens with Cu layers, consistent values were observed for undercut, neck thickness, and base thickness, regardless of plating thickness. However, the residual base thickness is higher than the reference on the die side and lower on the punch side. In contrast, specimens with an Au plating exhibited reduced undercut values, in some cases falling below the reference range, while neck thickness remained stable. Furthermore, the residual base thickness in these specimens showed considerable variation within one sectional view (cf. Figure 5 c and Figure 6). For the Cu cross plating, the undercut was generally too low, while neck thickness values remained within the acceptable range. However, significant altering of the interface shape in the base was observed, leading to variation of the residual base thickness similar to those seen in the gold-plated samples. In light of a rather undistorted interface in the bottom region of the reference joint (Figure 5 a), this indicates an altered shape of the interface with the undercut falling below the reference limit despite a comparable bottom thickness and reduced contact area of the Cu layer. To isolate the radiopaque interface layer in the grey-scale volume reconstructed from the CT data, a threshold-based segmentation method was applied. Surface determination tools within VGStudio were used to extract the layer from the surrounding material. Morphological operations such as opening, closing, and surface smoothing were subsequently performed to improve the quality of the extracted interface surface. The volume of the interface layer was then quantified. This procedure was carried out for both continuous copper platings and patterned cross copper platings. Figure 7 overlays cross-sectional views of continuous interface layers (blue) with cross-patterned layers (grey) of comparable thickness to improve recognizability. A largely continuous interface surface can be reconstructed from the CT data for all continuous platings as well as for the 19 µm thick cross-patterned layer. The platings significantly improve interface detectability compared to the reference. However, the data contains gaps in the base and neck regions in all plating types. This is due to a local reduction in layer thickness in these areas, whereas material accumulation is observed in the undercut region, leading to largely closed surface data in these areas. Although, areas of incomplete platings complicate the reliable extraction of joint geometry and the interface data, the recognizability is significantly better compared to the reference. In case of the cross-patterned platings, a lateral distortion of the pattern in the base region is observed (Figure 7 a and c) which might be caused by the manual cut-out of the cross in the tape. However, since the pattern remains centered in the neck region, also a non-uniform material flow during clinching could be responsible. Summary and Conclusions In situ CT can be used to capture internal phenomena during clinching processes to improve the validation of numerical models. However, joints made from the same materials (e.g., aluminum) offer low interface contrast in the CT image. In this work, electrical plating is applied to introduce contrast enhancing layers (Cu and Au) into the joining zone. The goal was to achieve sufficient interface detectability with minimal impact on joint formation and properties. It is shown, that electroplated Cu and Au layers can enhance contrast in order to detect the interface of a clinch point in a CT scan. A 7 µm Cu layer proved to offer the best trade-off between contrast enhancement and structural influence. In contrast, Au layers caused significant deviations in joint geometry and artefacts. Using a confined plating in form of a cross pattern showed a lower impact on friction and the clinching force. However, the interface shape and geometrical properties are also altered compared to the untreated reference specimen. To further improve the confined plating method and minimize its influence on joint properties, the following steps are suggested: Optimize the cross pattern design: Reduce the line width of the cross to minimize the coated area and further lower the friction and mechanical impact. Embed the plating: Introduce shallow recesses into the specimen surface using laser ablation, allowing the electroplated material to be embedded rather than surface-mounted. Improve tribological comparability: Polish the surface of the plating and apply a lubricant to both sheets prior to clinching to better replicate the tribological conditions of the reference process. Declarations Author Contribution Conceptualization, D.K.; methodology, D.K.; validation, D.K. and A.D; investigation, D.K. and A.D.; writing—original draft preparation, D.K. and A.D.; writing—review and editing, D.K., A.D., R.K., J.T., M.G.; supervision, R.K. and M.G.; project administration, R.K. and M.G.; funding acquisition, D.K., R.K., J.T. and M.G. All authors have read and agreed to the published version of the manuscript. Acknowledgement This research was funded by the German Research Foundation (DFG) within the project Transregional Collaborative Re-search Centre 285/2 (TRR 285/2, project number 418701707), sub-project C04 (project number 426959879). References Kalich J, Füssel U. Design of clinched joints on the basis of binding mechanisms. Prod. Eng. Res. Devel. 16, 213–222 (2022). https://doi.org/10.1007/s11740-022-01108-z Lambiase F, Di Ilio A. Mechanical clinching of metal–polymer joints. Journal of Materials Processing Technology 2015;215:12–9. https://doi.org/10.1016/j.jmatprotec.2014.08.006. Kappe F, Zirngibl C, Schleich B, Bobbert M, Wartzack S, Meschut G. Determining the influence of different process parameters on the versatile self-piercing riveting process using numerical methods. Journal of Manufacturing Processes 2022;84:1438–48. https://doi.org/10.1016/j.jmapro.2022.11.019. Köhler D, Kupfer R, Troschitz J, Gude M. Clinching in In Situ CT—A Novel Validation Method for Mechanical Joining Processes. In: Inal K, Levesque J, Worswick M, Butcher C, editors. NUMISHEET 2022: Proceedings of the 12th international conference and workshop on. [S.l.]: SPRINGER; 2022, p. 833–840. Köhler D, Kupfer R, Troschitz J, Gude M. Clinching in In-situ CT – Experimental Study on Suitable Tool Materials. ESAFORM 2021 2021. https://doi.org/10.25518/esaform21.2781. Köhler D, Kupfer R, Troschitz J, Gude M. Untersuchung zum Einfluss radioopaker Zwischenschichten bei der in-situ CT geclinchter Verbindungen. In: Zimmermann M, editor. Tagungsband der Tagung Werkstoffprüfung 2022; 2022. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 17 Sep, 2025 Read the published version in Journal of Nondestructive Evaluation → Version 1 posted Editorial decision: Revision requested 27 Jul, 2025 Reviews received at journal 20 Jul, 2025 Reviewers agreed at journal 17 Jul, 2025 Reviews received at journal 08 Jun, 2025 Reviewers agreed at journal 27 May, 2025 Reviewers invited by journal 08 May, 2025 Editor assigned by journal 06 May, 2025 Submission checks completed at journal 06 May, 2025 First submitted to journal 03 May, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6584984","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":453897222,"identity":"4df27191-d124-4e2b-9e41-b845975b660d","order_by":0,"name":"Daniel Köhler","email":"data:image/png;base64,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","orcid":"","institution":"TUD Dresden Universit of Technology","correspondingAuthor":true,"prefix":"","firstName":"Daniel","middleName":"","lastName":"Köhler","suffix":""},{"id":453897223,"identity":"e72ac8df-c3e1-4ad6-acb0-0edd180e6779","order_by":1,"name":"Alrik Dargel","email":"","orcid":"","institution":"TUD Dresden Universit of Technology","correspondingAuthor":false,"prefix":"","firstName":"Alrik","middleName":"","lastName":"Dargel","suffix":""},{"id":453897224,"identity":"c92681ea-4274-451b-9555-ce466dd2ebdc","order_by":2,"name":"Juliane Troschitz","email":"","orcid":"","institution":"TUD Dresden Universit of Technology","correspondingAuthor":false,"prefix":"","firstName":"Juliane","middleName":"","lastName":"Troschitz","suffix":""},{"id":453897225,"identity":"6b5bbcd7-c139-45f1-af85-c16f4ad92026","order_by":3,"name":"Maik Gude","email":"","orcid":"","institution":"TUD Dresden Universit of Technology","correspondingAuthor":false,"prefix":"","firstName":"Maik","middleName":"","lastName":"Gude","suffix":""},{"id":453897226,"identity":"138f8fd8-dd29-423b-9b61-8ff44fc41c9e","order_by":4,"name":"Robert Kupfer","email":"","orcid":"","institution":"TUD Dresden Universit of Technology","correspondingAuthor":false,"prefix":"","firstName":"Robert","middleName":"","lastName":"Kupfer","suffix":""}],"badges":[],"createdAt":"2025-05-03 15:53:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6584984/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6584984/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10921-025-01270-1","type":"published","date":"2025-09-17T15:56:52+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":82711564,"identity":"21572a2b-0597-4695-8648-a43b5ff107ab","added_by":"auto","created_at":"2025-05-14 11:34:34","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":215155,"visible":true,"origin":"","legend":"\u003cp\u003eEtching to remove the aluminum oxide layer from the whole surface (a), from the surface at the uncovered cross cutout (b), electroplating process with copper or gold (c), clinching (d) and CT scan of a specimen stack (e).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6584984/v1/aaff49225a9902ca590c7305.png"},{"id":82712721,"identity":"32550ef2-0573-48f6-b89e-d87b4c6949e9","added_by":"auto","created_at":"2025-05-14 11:42:34","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":521140,"visible":true,"origin":"","legend":"\u003cp\u003ePlated layers after electroplating exemplary specimens including the layer thickness.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6584984/v1/33c66af10dccfa538312968b.png"},{"id":82714115,"identity":"6ed978de-fd37-4686-b4f0-2853b3a6e5e9","added_by":"auto","created_at":"2025-05-14 11:58:34","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":75398,"visible":true,"origin":"","legend":"\u003cp\u003eActual plating thickness depending on the electric charge transferred during plating.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6584984/v1/28bbe0f0c594e59e718e446d.png"},{"id":82711567,"identity":"aabd8fcc-a855-4796-9881-7b6318813596","added_by":"auto","created_at":"2025-05-14 11:34:34","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":32821,"visible":true,"origin":"","legend":"\u003cp\u003eThe average and standard deviation of the maximum clinching forces (a) (reference: 6 specimens, plated: 4 specimens) and of the residual bottom thickness of the different plating methods. *The punch stroke was adapted to achieve the target bottom thickness of 0.7 mm +/- 0.02 mm.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6584984/v1/d5dd627632850b5d17c6b9a8.png"},{"id":82713310,"identity":"da1aa60a-bc75-451b-816f-2de4c35a0409","added_by":"auto","created_at":"2025-05-14 11:50:34","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":436882,"visible":true,"origin":"","legend":"\u003cp\u003eHalf cross sections (a-e) and full cross sections (f-g) of the CT images from exemplary specimens (same selection as in Figure 2)\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6584984/v1/353f9bda9c44cec66d0e8f9c.png"},{"id":82711568,"identity":"10189da6-e04c-4459-8254-3712a3058e3f","added_by":"auto","created_at":"2025-05-14 11:34:34","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":122363,"visible":true,"origin":"","legend":"\u003cp\u003eGeometrical properties of investigated plating methods and layer thicknesses\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-6584984/v1/a5855dc89999b85e8ceed1fb.png"},{"id":82711583,"identity":"8cb799ac-8cca-46aa-ad4a-b6a03b32e473","added_by":"auto","created_at":"2025-05-14 11:34:34","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":302654,"visible":true,"origin":"","legend":"\u003cp\u003eOverlaid surfaces of a Cu layer plating and a Cu cross plating for the layer thicknesses of 7 µm (a), 9 µm (b) and 19 µm (c)\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-6584984/v1/84ec2dda0c319c47543dd95c.png"},{"id":91889782,"identity":"d0a32f27-9713-4e58-bb38-c562c646d6f1","added_by":"auto","created_at":"2025-09-22 16:01:48","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2184479,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6584984/v1/0d68f42f-305e-4b69-98e3-be2d145835f5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"In Situ CT of Clinch Points – Enhancing Interface Detectability Using Electroplated Patterns of Radiopaque Materials","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLightweight design can benefit significantly from mechanical joining methods such as clinching, because different materials can be joined. The design of clinch points, however, often relies on the experience of clinch tool specialists [1] combined with iterative testing and tool adjustments [2]. Furthermore, the tool configuration is often tailored to a specific material-thickness combination [3]. To design clinching tools more effectively and adapt them more quickly to changing conditions, a better understanding of the phenomena occurring in the joining zone during both manufacturing and loading is required. Additionally, this understanding allows for more accurate validation of numerical models. Conventional investigation methods cannot capture all phenomena. For example, macroscopic analysis of the cross-section does not reflect the actual deformation and crack state during manufacturing, as spring-back effects during unloading and sample preparation can alter this state. Computed tomography (CT) enables a three-dimensional investigation without the destructive influence on the specimen. In situ CT of the clinching process, to add on, eliminates the effect of unloading, allowing for the detailed investigation of the chronological progression of phenomena throughout the process [4]. When clinching \u0026nbsp;equal materials, the sheet-sheet interface is hardly visible in CT due to the absence of an air gap caused by high contact forces in the joining zone. This impedes the post-processing of the CT data necessary for validation of numerical models. Earlier investigations showed that layers of radiopaque material can be applied between the joining parts to enhance the detectability of the sheet-sheet interface [5]. However, the layers caused strong artefacts and wrinkled during the clinching process [5] or changed the clinch joint’s properties significantly [6].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn this paper, a minimally invasive method to enhance the interface detectability is evaluated. For this, the outer oxide layer of an aluminum sheet is removed by etching. Then the sheet is locally electroplated in the joining zone with copper (Cu) or with gold (Au) and clinched with a non-treated aluminum sheet. The resulting interfaces are CT scanned and qualitatively evaluated. Moreover, the geometrical properties are measured and a software-driven layer extraction of the joint is tested. In initial tests, the optimum plating thickness is figured out by electroplating the whole surface in contact varying the process durations and plating material. In subsequent tests, it is tested whether the enhanced interface visualization can also be achieved using a mask to create a locally confined plating pattern while reducing the impact on the joining process.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eAll parts of the circular aluminum sheet (⌀ 40 mm for full-surface plating, ⌀ 20 mm for pattern plating, t = 2 mm)\u0026nbsp;which were not supposed to be electroplated are masked with blue flash tape in the joining zone (K7666\u003ca href=\"#_ftn1\" name=\"_ftnref1\" title=\"\"\u003e[1]\u003c/a\u003e) and package tape for the rest of the sheet. In order to create a sufficient bonding between plating and substrate, it is necessary to remove the aluminum oxide layer off the specimen. Therefore, the surface is etched using a sodium hydroxide solution (NaOH 20 %) for 2 min (Figure\u0026nbsp;1\u0026nbsp;a). After that, the residual hydroxide is removed using distilled water and the specimen is Cu or Au electroplated (Figure 1 c. For this, the specimen is electrically contacted with a direct current source (cathode). For Cu plating, a Cu plate is used as an anode. Both, anode and cathode, are submerged into a highly saturated solution of copper sulfate and positioned at a distance of ca. 10 cm from each other (Figure 1 c). For gold plating, a stainless-steel plate is used as anode and a gold solution\u003ca href=\"#_ftn2\" name=\"_ftnref2\" title=\"\"\u003e[2]\u003c/a\u003e (4 g / l) is used as electrolyte.\u003c/p\u003e\n\u003cp\u003eAccording to Faraday\u0026apos;s first law of electrolysis the amount of substance deposited or dissolved at an electrode during electrolysis is directly proportional to the quantity of electric charge passed through the electrolyte. Thus, with constant current, the mass of deposited copper \u0026nbsp; can be calculated with\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eIn initial tests, the entire surface is electroplated with either Cu or Au. For subsequent tests, the Cu plating is applied only to a reduced area in the form of a cross pattern (\u0026ldquo;cross plating\u0026rdquo;). This approach aims to minimize the influence on the joint\u0026rsquo;s mechanical properties while still enabling interface detection in two cross-sections. The pattern is created using the blue masking tape with a cross-shaped cutout (0.5 mm line width, 20 mm diameter), as shown in Figure 1 b. Platings with target thicknesses from 2.5, 5, 10 and 20 \u0026micro;m are created (1 specimen per thickness). Based on Faraday\u0026apos;s first law of electrolysis, these thicknesses are expected by adjusting the plating process duration, as outlined in Table 1. The actual plating thickness is measured thereafter. The electric current is set at 0.3 A for the whole surface copper plating and at 0.1 A for the whole surface gold and cross plating. In order to improve adhesion of gold on aluminum, a copper strike layer of 2 \u0026ndash; 7 \u0026micro;m thickness is applied before gold platting. After clinching the plated with the non-plated specimen, the clinch point is CT scanned to evaluate the interface detectability.\u003c/p\u003e\n\u003cp\u003eTable 1. Plating durations in min. Plating with copper strike layer thickness of 2 \u0026micro;m (*) and 5 \u0026ndash; 9 \u0026micro;m (**).\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eCoating method\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003eElectric current [A]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003eTarget layer thickness [\u0026micro;m]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003eCoating duration [min]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003eActual layer thickness [\u0026micro;m]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" style=\"width: 161px;\"\u003e\n \u003cp\u003eCu layer\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"4\" style=\"width: 89px;\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e4.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e9.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 161px;\"\u003e\n \u003cp\u003eCu strike\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 89px;\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e4.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e9.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e5 \u0026ndash; 9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" style=\"width: 161px;\"\u003e\n \u003cp\u003eAu layer\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"4\" style=\"width: 89px;\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e1.25*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e2.5**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e9.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e5**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e19.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e15**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" style=\"width: 161px;\"\u003e\n \u003cp\u003eCu cross\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"4\" style=\"width: 89px;\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e6.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e19.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eThe electric charge for each coating test and the resulting plating thickness can be seen in Figure 3. Notably, the relationship approximates a linear increase. While the steeper incline for the copper cross pattern can be explained with the reduced plating surface, the flat increase for Au plating indicates a lower process efficiency than copper plating. In Figure 2 a set of exemplarily selected specimens after electroplating is shown beside an aluminum sheet without plating for comparison. In (b) can be noticed, how the layer is more consistent at the edges (darker) and more porous in the center (brighter) resulting from the short electroplating duration. Otherwise, the layers appear uniform and consistent. In (c) the Impurities on the sample are probably due to diffusion of copper through the gold layer and subsequent oxidation of the copper. Also, the cross patterns show a clear edge. However, due to the manual cutting of the cross pattern cut out in the tape, the crosses deviate slightly from the center of the specimen.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe plated specimen is clinched with a non-plated counterpart using the punch A50100[3] and the die BE8012[4] on a ZwickRoell 1465 testing machine (single-step, rotationally symmetric joint without cut section). A column frame is used to improve alignment of the tools (Figure 1 d). Thereafter, a stack of specimens is scanned in a single CT scan with helical trajectory applying the parameters shown in Table 2. Finally, the CT images are reconstructed using datos|x 2 rec[5] and evaluated in VG Studio Max 3.4[6]\u003c/p\u003e\n\u003cp\u003eTable 2: CT parameters\u003c/p\u003e\n\u003cdiv align=\"Left\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003eParameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003eUnit\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003eValue\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003eAcceleration voltage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003e[kV]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e150\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003eTube current\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003e[\u0026micro;A]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003eFocal spot size\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003e[\u0026micro;m]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003eVoxel size\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003e[\u0026micro;m]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003ePhysical filter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003e[mm]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e0.5 (Cu)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003eExposure time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003e[ms]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e500\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003eAveraging\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003eSkip\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 176px;\"\u003e\n \u003cp\u003eX-ray projections\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 79px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2016\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e[1] Suter Kunststoffe AG, Aefligenstrasse 3, 3312 Fraubrunnen, Switzerland\u003c/p\u003e\n\u003cp\u003e[2] Betzmann Galvanik, Am Berghof 20, 88630 Pfullendorf, Germany\u003c/p\u003e\n\u003cp\u003e[3] TOX PRESSOTECHNIK GmbH \u0026amp; Co.KG, Weingarten, Germany\u003c/p\u003e\n\u003cp\u003e[4] TOX PRESSOTECHNIK GmbH \u0026amp; Co.KG, Weingarten, Germany\u003c/p\u003e\n\u003cp\u003e[5] Baker Hughes Company, 2001 Rankin Road, Houston, Texas 77073, USA\u003c/p\u003e\n\u003cp\u003e[6] Volume Graphics GmbH, Speyerer Stra\u0026szlig;e 4 \u0026ndash; 6, 69115 Heidelberg, Germany\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cp\u003eFigure 4 shows both the average maximum clinching force and the average residual bottom thickness, including standard deviations, for each plating method. The average forces are 7-8 % higher than in the reference clinching process (without contrast-enhancing layer). Since both the maximum clinching force and residual bottom thickness directly depend on the punch stroke, this factor must be taken into account. The reference clinching force resulted from a punch stroke of 5.43 mm, while the specimens with Cu and Cu strike and Au layers were clinched with slightly reduced punch stroke of \u0026nbsp; 5.38 mm. The increased thickness of the stacked sheets to be joined and the higher friction resulting from the degreased plated surfaces led to an increase in both the maximum force and the residual bottom thickness. Adjusting the punch stroke to match the residual bottom thickness of the reference would have led to even higher forces. In the case of Cu cross specimens, the punch stroke was adapted to 5.54 mm to achieve a residual bottom thickness similar to the reference. Despite the reduced treatment surface for the cross-pattern plating, the clinching force remained 7 % higher than in the reference process.\u003c/p\u003e\n\u003cp\u003eFigure 5 shows the CT cross-sections of the example specimens from Figure 2. Specimens with a Cu strike Au layer exhibit strong beam hardening artifacts (b, c), which hinder automatic interface detection. Additionally, the contrast material appears to alter the interface course in the bottom region of the joint (c). The specimen with a 4 \u0026micro;m Cu layer shows low interface visibility in the bottom region (d). However, air-filled gaps allow partial interface detection, enabling a volume segmentation with minor inaccuracies during post processing of the CT data. Increasing the Cu layer to 7 \u0026micro;m results in a nearly continuous presence of the contrast layer, with only slight accumulation in the undercut region (e).\u003c/p\u003e\n\u003cp\u003eSpecimens with cross plating with very low thickness show similar partial detectability in the bottom region (f). For thicker cross platings, the contrast material appears distorted along the bottom interface (g), likely due to insufficient adhesion and contact surface to the substrate aluminum sheet.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;To quantify the joint quality, geometrical properties were evaluated for all investigated plating methods, including full-surface Cu layer, Cu strike and Au layer, and Cu cross platings. Using the CT images, for each specimen, the undercut and neck thickness were measured on the left and right side in two sectional views oriented 90\u0026deg; apart. For the purpose of further analysis, the mean values from the set of four measurements were utilized. Additionally, the minimum residual base thickness was determined separately for the punch-side and the die-side. Therefore, the minimum distance from the interface to the surface of the punch-side respectively die side from both sectional views was measured. The results are summarized in Figure 6, which also indicates the ranges for undercut, neck thickness, and minimum residual base thickness of the reference specimen without plating. Across all specimens with Cu layers, consistent values were observed for undercut, neck thickness, and base thickness, regardless of plating thickness. However, the residual base thickness is higher than the reference on the die side and lower on the punch side. In contrast, specimens with an Au plating exhibited reduced undercut values, in some cases falling below the reference range, while neck thickness remained stable. Furthermore, the residual base thickness in these specimens showed considerable variation within one sectional view (cf. Figure 5 c and Figure 6). For the Cu cross plating, the undercut was generally too low, while neck thickness values remained within the acceptable range. However, significant altering of the interface shape in the base was observed, leading to variation of the residual base thickness similar to those seen in the gold-plated samples. In light of a rather undistorted interface in the bottom region of the reference joint (Figure 5 a), this indicates an altered shape of the interface with the undercut falling below the reference limit despite a comparable bottom thickness and reduced contact area of the Cu layer.\u003c/p\u003e\n\u003cp\u003eTo isolate the radiopaque interface layer in the grey-scale volume reconstructed from the CT data, a threshold-based segmentation method was applied. Surface determination tools within VGStudio were used to extract the layer from the surrounding material. Morphological operations such as opening, closing, and surface smoothing were subsequently performed to improve the quality of the extracted interface surface. The volume of the interface layer was then quantified. This procedure was carried out for both continuous copper platings and patterned cross copper platings. Figure 7 overlays cross-sectional views of continuous interface layers (blue) with cross-patterned layers (grey) of comparable thickness to improve recognizability. A largely continuous interface surface can be reconstructed from the CT data for all continuous platings as well as for the 19 \u0026micro;m thick cross-patterned layer. The platings significantly improve interface detectability compared to the reference. However, the data \u0026nbsp;contains gaps in the base and neck regions in all plating types. This is due to a local reduction in layer thickness in these areas, whereas material accumulation is observed in the undercut region, leading to largely closed surface data in these areas. Although, areas of incomplete platings complicate the reliable extraction of joint geometry and the interface data, the recognizability is significantly better compared to the reference. In case of the cross-patterned platings, a lateral distortion of the pattern in the base region is observed (Figure 7 a and c) which might be caused by the manual cut-out of the cross in the tape. However, since the pattern remains centered in the neck region, also a non-uniform material flow during clinching could be responsible.\u003c/p\u003e"},{"header":"Summary and Conclusions","content":"\u003cp\u003eIn situ CT can be used to capture internal phenomena during clinching processes to improve the validation of numerical models. \u0026nbsp; However, joints made from the same materials (e.g., aluminum) offer low interface contrast in the CT image. In this work, electrical plating is applied to introduce contrast enhancing layers (Cu and Au) into the joining zone. The goal was to achieve sufficient interface detectability with minimal impact on joint formation and properties. It is shown, that electroplated Cu and Au layers can enhance contrast in order to detect the interface of a clinch point in a CT scan. A 7 \u0026micro;m Cu layer proved to offer the best trade-off between contrast enhancement and structural influence. In contrast, Au layers caused significant deviations in joint geometry and artefacts. Using a confined plating in form of a cross pattern showed a lower impact on friction and the\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eclinching force. However, the interface shape and geometrical properties are also altered compared to the untreated reference specimen.\u003c/p\u003e\n\u003cp\u003eTo further improve the confined plating method and minimize its influence on joint properties, the following steps are suggested:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eOptimize the cross pattern design: Reduce the line width of the cross to minimize the coated area and further lower the friction and mechanical impact.\u003c/li\u003e\n \u003cli\u003eEmbed the plating: Introduce shallow recesses into the specimen surface using laser ablation, allowing the electroplated material to be embedded rather than surface-mounted.\u003c/li\u003e\n \u003cli\u003eImprove tribological comparability: Polish the surface of the plating and apply a lubricant to both sheets prior to clinching to better replicate the tribological conditions of the reference process.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eConceptualization, D.K.; methodology, D.K.; validation, D.K. and A.D; investigation, D.K. and A.D.; writing\u0026mdash;original draft preparation, D.K. and A.D.; writing\u0026mdash;review and editing, D.K., A.D., R.K., J.T., M.G.; supervision, R.K. and M.G.; project administration, R.K. and M.G.; funding acquisition, D.K., R.K., J.T. and M.G. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThis research was funded by the German Research Foundation (DFG) within the project Transregional Collaborative Re-search Centre 285/2 (TRR 285/2, project number 418701707), sub-project C04 (project number 426959879).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eKalich J, F\u0026uuml;ssel U. Design of clinched joints on the basis of binding mechanisms. Prod. Eng. Res. Devel. 16, 213\u0026ndash;222 (2022). https://doi.org/10.1007/s11740-022-01108-z\u003c/li\u003e\n \u003cli\u003eLambiase F, Di Ilio A. Mechanical clinching of metal\u0026ndash;polymer joints. Journal of Materials Processing Technology 2015;215:12\u0026ndash;9. https://doi.org/10.1016/j.jmatprotec.2014.08.006.\u003c/li\u003e\n \u003cli\u003eKappe F, Zirngibl C, Schleich B, Bobbert M, Wartzack S, Meschut G. Determining the influence of different process parameters on the versatile self-piercing riveting process using numerical methods. Journal of Manufacturing Processes 2022;84:1438\u0026ndash;48. https://doi.org/10.1016/j.jmapro.2022.11.019.\u003c/li\u003e\n \u003cli\u003eK\u0026ouml;hler D, Kupfer R, Troschitz J, Gude M. Clinching in In Situ CT\u0026mdash;A Novel Validation Method for Mechanical Joining Processes. In: Inal K, Levesque J, Worswick M, Butcher C, editors. NUMISHEET 2022: Proceedings of the 12th international conference and workshop on. [S.l.]: SPRINGER; 2022, p. 833\u0026ndash;840.\u003c/li\u003e\n \u003cli\u003eK\u0026ouml;hler D, Kupfer R, Troschitz J, Gude M. Clinching in In-situ CT \u0026ndash; Experimental Study on Suitable Tool Materials. ESAFORM 2021 2021. https://doi.org/10.25518/esaform21.2781.\u003c/li\u003e\n \u003cli\u003eK\u0026ouml;hler D, Kupfer R, Troschitz J, Gude M. Untersuchung zum Einfluss radioopaker Zwischenschichten bei der in-situ CT geclinchter Verbindungen. In: Zimmermann M, editor. Tagungsband der Tagung Werkstoffpr\u0026uuml;fung 2022; 2022.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-nondestructive-evaluation","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jone","sideBox":"Learn more about [Journal of Nondestructive Evaluation](http://link.springer.com/journal/10921)","snPcode":"10921","submissionUrl":"https://submission.nature.com/new-submission/10921/3","title":"Journal of Nondestructive Evaluation","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Clinching, In situ computed tomography, Non-destructive testing, Interface visibility","lastPublishedDoi":"10.21203/rs.3.rs-6584984/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6584984/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eA clinch point’s quality is usually assessed using ex-situ destructive testing methods. These, however, are unable to detect phenomena immediately during the joining process. For instance, elastic deformations reverse and cracks close after unloading. In situ methods such as the force-displacement evaluation are used to investigate a clinching process, though deviations in the clinch point geometry cannot be derived with this method. To overcome these limitations, the clinching process can be investigated using in situ computed tomography (in situ CT) using tool materials suitable for X-ray investigation. When joining aluminum parts, the sheet-sheet interface is hardly visible. Earlier investigations showed that radiopaque materials can be applied between the joining parts to enhance the detectability of the sheet-sheet interface. However, the layers cause strong artefacts, break during the clinching process or change the clinch joint’s properties significantly. In this paper, a minimally invasive method to enhance the interface detectability is presented. First, the aluminum oxide layer is removed by etching. Second, the specimen is electroplated with copper or gold, respectively. In some cases, a mask is applied to create a cross-shaped plating pattern. Then, the plated specimen is clinched with a non-plated counterpart and the interface detectability is assessed in CT scans of the clinch points. It is shown that a copper plating of 2.6-4 µm can visualize some parts of the interface, while 7-9 µm is suitable to enhance the detectability of the sheet-sheet interface almost continuously.\u003c/p\u003e","manuscriptTitle":"In Situ CT of Clinch Points – Enhancing Interface Detectability Using Electroplated Patterns of Radiopaque Materials","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-14 11:34:29","doi":"10.21203/rs.3.rs-6584984/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-07-27T15:13:21+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-20T14:41:18+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"243338966919781700356026270628906475524","date":"2025-07-17T12:50:06+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-08T18:22:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"234883914580565167075353249373879034052","date":"2025-05-27T16:05:32+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-08T09:39:07+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-06T14:37:21+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-05-06T04:46:29+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Nondestructive Evaluation","date":"2025-05-03T15:44:01+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-nondestructive-evaluation","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jone","sideBox":"Learn more about [Journal of Nondestructive Evaluation](http://link.springer.com/journal/10921)","snPcode":"10921","submissionUrl":"https://submission.nature.com/new-submission/10921/3","title":"Journal of Nondestructive Evaluation","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"db217e65-696e-41d1-848d-064974e0843a","owner":[],"postedDate":"May 14th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-09-22T15:58:55+00:00","versionOfRecord":{"articleIdentity":"rs-6584984","link":"https://doi.org/10.1007/s10921-025-01270-1","journal":{"identity":"journal-of-nondestructive-evaluation","isVorOnly":false,"title":"Journal of Nondestructive Evaluation"},"publishedOn":"2025-09-17 15:56:52","publishedOnDateReadable":"September 17th, 2025"},"versionCreatedAt":"2025-05-14 11:34:29","video":"","vorDoi":"10.1007/s10921-025-01270-1","vorDoiUrl":"https://doi.org/10.1007/s10921-025-01270-1","workflowStages":[]},"version":"v1","identity":"rs-6584984","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6584984","identity":"rs-6584984","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}