Mechanical Behavior of Dissimilar Friction Stir Welded T-joints between Aluminum Alloy and Steel: Role of Kissing Bonds, Intermetallic Compounds, and Microstructural Evolution

Mechanical Behavior of Dissimilar Friction Stir Welded T-joints between Aluminum Alloy and Steel: Role of Kissing Bonds, Intermetallic Compounds, and Microstructural Evolution | 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 Mechanical Behavior of Dissimilar Friction Stir Welded T-joints between Aluminum Alloy and Steel: Role of Kissing Bonds, Intermetallic Compounds, and Microstructural Evolution Quan Minh Nguyen, Hao Dinh Duong, Tra Hung Tran This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9587701/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract This study investigates the mechanical behavior of dissimilar friction stir welded (FSWed) T-joints of AA6061/steel, focusing on the roles of kissing bonds (KBs), intermetallic compounds (IMCs), and microstructural evolution. The T-joints were fabricated at the welding speeds of 100–250 mm/min and characterized by SEM, EDS, XRD and tensile testing for both skin and stringer loading. The finite element analysis was also applied to clarify the fracture behavior of the T-joint. The results show that both KBs and IMCs are unavoidable and strongly dependent on welding conditions. At low welding speeds, thick and brittle IMC layers consisting of Fe 2 Al 5 and FeAl 3 phases, together with interfacial micro-cracks, dominate crack initiation, reducing joint strength despite limited crack opening. At higher speeds, IMC formation is suppressed, but unfavorable KB geometry promotes crack propagation, leading to strength reduction. The stringer strength is significantly lower than the skin strength, indicating that interfacial defects govern failure. Microstructural evolution has a secondary effect, mainly influencing skin behavior. The optimal welding speed is 150 mm/min, where reduced IMC brittleness and favorable KB geometry result in the highest joint strength. Steel FSW T-joint interface AA6061 intermetallic diffusion defect microstructure strength Full Text Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 05 May, 2026 Reviewers invited by journal 05 May, 2026 Editor invited by journal 05 May, 2026 Editor assigned by journal 04 May, 2026 First submitted to journal 01 May, 2026 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. 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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-9587701","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":634926484,"identity":"9882bf61-1a40-4553-aa57-da69750222a2","order_by":0,"name":"Quan Minh Nguyen","email":"","orcid":"","institution":"Nha Trang University","correspondingAuthor":false,"prefix":"","firstName":"Quan","middleName":"Minh","lastName":"Nguyen","suffix":""},{"id":634926485,"identity":"94071d2a-95b3-47d0-8f9c-5132d01a4aef","order_by":1,"name":"Hao Dinh Duong","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvklEQVRIiWNgGAWjYDCCwwxszEBKDsJjI0GLMUQ1UVoOQLQkNhCthe8477HHBTU26dvlewwYPpQdZjC43YBfi+RhvnTjGcfScne28RgwzjgH1HLnAH4tBod5zKR52A7nbjjGY8DM23aYQXJGAjFa/h1ONwBp+Uu0FqDhCWAtjEAt/BIEtEiCtfSlGW44llZwsOdcOg9BLXznzwAd9s1G3uDw4Y0PfpRZy7ER0oICDgAxDwnqR8EoGAWjYBTgAgC4aDx9jnNO4AAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-7071-8638","institution":"Nha Trang University","correspondingAuthor":true,"prefix":"","firstName":"Hao","middleName":"Dinh","lastName":"Duong","suffix":""},{"id":634926486,"identity":"1adb4773-6aeb-4cae-a686-d22908b7827b","order_by":2,"name":"Tra Hung Tran","email":"","orcid":"","institution":"Nha Trang University","correspondingAuthor":false,"prefix":"","firstName":"Tra","middleName":"Hung","lastName":"Tran","suffix":""}],"badges":[],"createdAt":"2026-05-01 15:59:54","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9587701/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9587701/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109168130,"identity":"3c0dd169-932e-4e7c-97ac-e17b30fc0540","added_by":"auto","created_at":"2026-05-13 08:31:56","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2259039,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9587701/v1_covered_c49ea8bb-7704-43ff-a3f7-c78e9a495bb6.pdf"}],"financialInterests":"","formattedTitle":"Mechanical Behavior of Dissimilar Friction Stir Welded T-joints between Aluminum Alloy and Steel: Role of Kissing Bonds, Intermetallic Compounds, and Microstructural Evolution","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"welding-in-the-world","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"witw","sideBox":"Learn more about [Welding in the World](https://www.springer.com/journal/40194)","snPcode":"40194","submissionUrl":"https://www.editorialmanager.com/witw/","title":"Welding in the World","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Steel, FSW, T-joint, interface, AA6061, intermetallic, diffusion, defect, microstructure, strength","lastPublishedDoi":"10.21203/rs.3.rs-9587701/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9587701/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study investigates the mechanical behavior of dissimilar friction stir welded (FSWed) T-joints of AA6061/steel, focusing on the roles of kissing bonds (KBs), intermetallic compounds (IMCs), and microstructural evolution. The T-joints were fabricated at the welding speeds of 100\u0026ndash;250 mm/min and characterized by SEM, EDS, XRD and tensile testing for both skin and stringer loading. The finite element analysis was also applied to clarify the fracture behavior of the T-joint. The results show that both KBs and IMCs are unavoidable and strongly dependent on welding conditions. At low welding speeds, thick and brittle IMC layers consisting of Fe\u003csub\u003e2\u003c/sub\u003eAl\u003csub\u003e5\u003c/sub\u003e and FeAl\u003csub\u003e3\u003c/sub\u003e phases, together with interfacial micro-cracks, dominate crack initiation, reducing joint strength despite limited crack opening. At higher speeds, IMC formation is suppressed, but unfavorable KB geometry promotes crack propagation, leading to strength reduction. The stringer strength is significantly lower than the skin strength, indicating that interfacial defects govern failure. Microstructural evolution has a secondary effect, mainly influencing skin behavior. The optimal welding speed is 150 mm/min, where reduced IMC brittleness and favorable KB geometry result in the highest joint strength.\u003c/p\u003e","manuscriptTitle":"Mechanical Behavior of Dissimilar Friction Stir Welded T-joints between Aluminum Alloy and Steel: Role of Kissing Bonds, Intermetallic Compounds, and Microstructural Evolution","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-13 08:26:53","doi":"10.21203/rs.3.rs-9587701/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2026-05-06T03:45:06+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-05-05T15:33:04+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Welding in the World","date":"2026-05-05T05:11:41+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-05-04T13:35:45+00:00","index":"","fulltext":""},{"type":"submitted","content":"Welding in the World","date":"2026-05-01T11:59:45+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"welding-in-the-world","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"witw","sideBox":"Learn more about [Welding in the World](https://www.springer.com/journal/40194)","snPcode":"40194","submissionUrl":"https://www.editorialmanager.com/witw/","title":"Welding in the World","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"679d50eb-e932-42da-8316-5cfda996c02c","owner":[],"postedDate":"May 13th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"","date":"2026-05-06T03:45:06+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-05-05T15:33:04+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Welding in the World","date":"2026-05-05T05:11:41+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-05-04T13:35:45+00:00","index":"","fulltext":""},{"type":"submitted","content":"Welding in the World","date":"2026-05-01T11:59:45+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-13T08:26:53+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-13 08:26:53","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9587701","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9587701","identity":"rs-9587701","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}