Chemical composition gradients within an In-situ alloyed tungsten-tantalum laser powder-bed fusion: modelling and validation

Chemical composition gradients within an In-situ alloyed tungsten-tantalum laser powder-bed fusion: modelling and validation | 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 Chemical composition gradients within an In-situ alloyed tungsten-tantalum laser powder-bed fusion: modelling and validation Richard Turner, Ahmet Guner, Abd El-Moez A. Mohamed, Dina Fouad, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8163781/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Tungsten remains a material of considerable interest to engineers for nuclear fusion reactor designs, in particular for the plasma-facing components (PFCs) thanks to its outstanding thermal conductivity and unmatched high melting point. However, tungsten remains a difficult to additively manufacture metal, due to its highly brittle nature, leading to cracking during cooling. Tantalum can be alloyed with the tungsten within a laser-based powder bed fusion (LPBF) manufacture by blending of elemental W and Ta powders, in a ratio of approximately 92 wt.% W to 8 wt.% Ta, which allows the LPBF builds to not experience cracking during cooling. However, it becomes of interest to understand any compositional gradients which may occur during in-situ alloying. An 85mm tall cylinder was manufactured via LPBF and was sectioned and analysed for chemical composition variation along the height. Whilst a discrete element modelling (DEM) framework was developed to simulate the powder behaviour during the tipping / pouring and the LPBF spreading motion. Both model prediction and experimental measurement agreed that the W powder segregates in higher concentrations toward the top of the build, whilst the Ta powder segregates to higher concentrations toward the bottom of the build. Experimental measurements suggest a +/- 1% variation from the nominal composition, whilst DEM predictions were a little wider, at +/- 2%. It is noted that a compositional gradient in the build may limit the end-application of LPBF built components due to issues with in-service performance thermally and mechanically, however this would need to be assessed on a case-by-case basis, as blends with smaller compositional gradient or different alloying elements may have varying effects upon performance. discrete element modelling in-situ alloying chemical composition location-specific properties thermal conductivity Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted 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-8163781","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":558080374,"identity":"9ac63caf-3a70-4c1a-a163-864b67166589","order_by":0,"name":"Richard Turner","email":"","orcid":"","institution":"University of Birmingham","correspondingAuthor":false,"prefix":"","firstName":"Richard","middleName":"","lastName":"Turner","suffix":""},{"id":558080375,"identity":"9762f042-b2a5-4162-b063-e3c8a50c4fac","order_by":1,"name":"Ahmet Guner","email":"","orcid":"","institution":"University of Birmingham","correspondingAuthor":false,"prefix":"","firstName":"Ahmet","middleName":"","lastName":"Guner","suffix":""},{"id":558080376,"identity":"f91597f4-0b1b-458b-bca4-75d89a313873","order_by":2,"name":"Abd El-Moez A. 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conductivity","lastPublishedDoi":"10.21203/rs.3.rs-8163781/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8163781/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTungsten remains a material of considerable interest to engineers for nuclear fusion reactor designs, in particular for the plasma-facing components (PFCs) thanks to its outstanding thermal conductivity and unmatched high melting point. However, tungsten remains a difficult to additively manufacture metal, due to its highly brittle nature, leading to cracking during cooling. Tantalum can be alloyed with the tungsten within a laser-based powder bed fusion (LPBF) manufacture by blending of elemental W and Ta powders, in a ratio of approximately 92 wt.% W to 8 wt.% Ta, which allows the LPBF builds to not experience cracking during cooling. However, it becomes of interest to understand any compositional gradients which may occur during in-situ alloying. An 85mm tall cylinder was manufactured via LPBF and was sectioned and analysed for chemical composition variation along the height. Whilst a discrete element modelling (DEM) framework was developed to simulate the powder behaviour during the tipping / pouring and the LPBF spreading motion. Both model prediction and experimental measurement agreed that the W powder segregates in higher concentrations toward the top of the build, whilst the Ta powder segregates to higher concentrations toward the bottom of the build. Experimental measurements suggest a +/- 1% variation from the nominal composition, whilst DEM predictions were a little wider, at +/- 2%. It is noted that a compositional gradient in the build may limit the end-application of LPBF built components due to issues with in-service performance thermally and mechanically, however this would need to be assessed on a case-by-case basis, as blends with smaller compositional gradient or different alloying elements may have varying effects upon performance.\u003c/p\u003e","manuscriptTitle":"Chemical composition gradients within an In-situ alloyed tungsten-tantalum laser powder-bed fusion: modelling and validation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-15 09:58:36","doi":"10.21203/rs.3.rs-8163781/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":"51859f2d-b694-41f6-84fd-a70654661cea","owner":[],"postedDate":"December 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-06T15:10:20+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-15 09:58:36","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8163781","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8163781","identity":"rs-8163781","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}