Investigating a novel approach to reduce transverse weld scrap in aluminum extrusion using profiled dummy blocks and billets

Investigating a novel approach to reduce transverse weld scrap in aluminum extrusion using profiled dummy blocks and billets | 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 Investigating a novel approach to reduce transverse weld scrap in aluminum extrusion using profiled dummy blocks and billets Muhammad Umar Farooq, Gregory Oberhausen, Daniel R. Cooper This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6838868/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 06 Aug, 2025 Read the published version in International Journal of Material Forming → Version 1 posted You are reading this latest preprint version Abstract The supply chains of extruded aluminum are materially inefficient, with up to two-fifths of the billet being scrapped before the profile is incorporated into a final product. A significant source of process scrap arises from removing the tongue-shaped transverse weld—also known as the front-end defect or charge weld—that is formed between the consecutive billets being extruded, primarily because of concerns over weld integrity. Optimizing process settings and die geometry can reduce the transverse weld length—and thus the amount of scrapped material—but only by approximately 15%. We investigate a novel methodology for significant scrap reduction, where an initially profiled interface—rather than a flat one—between consecutively extruded billets compensates for the differential velocities of material across the billet cross-section as it moves through the die ports, resulting in shorter welds. This profiled interface is created using profiled billets that fit into a dummy block shaped with the inverse of the billet profile. We present a design process to define the shape of the profiled dummy block and billet. For a given part, we first determine the ideal shape by obtaining the velocity field from finite element simulations of the conventional extrusion process, assuming perfectly rigid tooling and no constraints on the creation of profiled tooling or billets. Next, we rationalize this shape by applying stress and deflection limits to the dummy block, ensuring it avoids plastic deformation and interference with the container wall. Additionally, we consider ductile damage limits for the billet to prevent cracking during a pre-extrusion hot forging stage, which is one method of generating profiled billets. The design process is applied to four profiles of increasing complexity: solid round and rectangular bars, a square-tube hollow, and a complex multi-hollow profile. Extrusion and forging trials using custom-built tooling are conducted to validate the design process. The experimental case studies demonstrate that profiled dummy blocks and billets can achieve weld length reductions of over 50% and that the same tooling can offer scrap savings across a range of similar extruded shapes. In the tests, a profiled dummy block with an air escape vent showed zero-to-negligible plastic deformation and neither air entrapment nor clogging of the vent during extrusion, while a conventional billet was hot-forged to produce profiled ends without cracking or deforming the forging tools. Overall, this study highlights that profiled billet extrusion is a promising technology for significantly reducing scrap from transverse weld removal in aluminum extrusions. sustainability transverse weld material efficiency dummy block aluminum extrusion tooling design process design Full Text Additional Declarations No competing interests reported. Supplementary Files SIexweldreduction.pdf Cite Share Download PDF Status: Published Journal Publication published 06 Aug, 2025 Read the published version in International Journal of Material Forming → Version 1 posted 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. 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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-6838868","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":475119671,"identity":"771f48b6-b7bf-401c-b923-ca171fab8b14","order_by":0,"name":"Muhammad Umar Farooq","email":"","orcid":"","institution":"University of Michigan","correspondingAuthor":false,"prefix":"","firstName":"Muhammad","middleName":"Umar","lastName":"Farooq","suffix":""},{"id":475119672,"identity":"94cad099-2ce4-452c-bfa1-2ee72249c250","order_by":1,"name":"Gregory Oberhausen","email":"","orcid":"","institution":"University of Michigan","correspondingAuthor":false,"prefix":"","firstName":"Gregory","middleName":"","lastName":"Oberhausen","suffix":""},{"id":475119673,"identity":"6ee5731c-1bc1-4557-88e3-fcb6adbb0482","order_by":2,"name":"Daniel R. 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A significant source of process scrap arises from removing the tongue-shaped transverse weld—also known as the front-end defect or charge weld—that is formed between the consecutive billets being extruded, primarily because of concerns over weld integrity. Optimizing process settings and die geometry can reduce the transverse weld length—and thus the amount of scrapped material—but only by approximately 15%. We investigate a novel methodology for significant scrap reduction, where an initially profiled interface—rather than a flat one—between consecutively extruded billets compensates for the differential velocities of material across the billet cross-section as it moves through the die ports, resulting in shorter welds. This profiled interface is created using profiled billets that fit into a dummy block shaped with the inverse of the billet profile. We present a design process to define the shape of the profiled dummy block and billet. For a given part, we first determine the ideal shape by obtaining the velocity field from finite element simulations of the conventional extrusion process, assuming perfectly rigid tooling and no constraints on the creation of profiled tooling or billets. Next, we rationalize this shape by applying stress and deflection limits to the dummy block, ensuring it avoids plastic deformation and interference with the container wall. Additionally, we consider ductile damage limits for the billet to prevent cracking during a pre-extrusion hot forging stage, which is one method of generating profiled billets. The design process is applied to four profiles of increasing complexity: solid round and rectangular bars, a square-tube hollow, and a complex multi-hollow profile. Extrusion and forging trials using custom-built tooling are conducted to validate the design process. The experimental case studies demonstrate that profiled dummy blocks and billets can achieve weld length reductions of over 50% and that the same tooling can offer scrap savings across a range of similar extruded shapes. In the tests, a profiled dummy block with an air escape vent showed zero-to-negligible plastic deformation and neither air entrapment nor clogging of the vent during extrusion, while a conventional billet was hot-forged to produce profiled ends without cracking or deforming the forging tools. Overall, this study highlights that profiled billet extrusion is a promising technology for significantly reducing scrap from transverse weld removal in aluminum extrusions.","manuscriptTitle":"Investigating a novel approach to reduce transverse weld scrap in aluminum extrusion using profiled dummy blocks and billets","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-01 05:30:06","doi":"10.21203/rs.3.rs-6838868/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e4cdfeb0-f84a-4212-a329-35c885b33ff8","owner":[],"postedDate":"July 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-08-11T16:04:23+00:00","versionOfRecord":{"articleIdentity":"rs-6838868","link":"https://doi.org/10.1007/s12289-025-01926-3","journal":{"identity":"international-journal-of-material-forming","isVorOnly":false,"title":"International Journal of Material Forming"},"publishedOn":"2025-08-06 15:58:09","publishedOnDateReadable":"August 6th, 2025"},"versionCreatedAt":"2025-07-01 05:30:06","video":"","vorDoi":"10.1007/s12289-025-01926-3","vorDoiUrl":"https://doi.org/10.1007/s12289-025-01926-3","workflowStages":[]},"version":"v1","identity":"rs-6838868","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6838868","identity":"rs-6838868","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}