Formability Improvement Mechanism of Local Laser Hardened Aluminium Alloy Sheet with Gradient Material Model

Formability Improvement Mechanism of Local Laser Hardened Aluminium Alloy Sheet with Gradient Material Model | 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 Formability Improvement Mechanism of Local Laser Hardened Aluminium Alloy Sheet with Gradient Material Model Xiao-song Zhang, Shuai-feng Chen, Hong-wu Song, Xue-jian Yang, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8875960/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 To solving the difficulty of forming complex parts of aluminum alloy, a method was proposed using local hardening by laser heat treatment (LHT) to improve the formability of the Al alloy sheet. In order to explore the influence of laser local hardening on deep drawing forming performance, the temperature field of laser treatment was simulated based on the measured data, and a sheet model coupled with mechanical property gradient was established. In addition, the mechanism of the improvement of material formability by the change of constitutive parameters was revealed by the combination of simulation and experiment. The results show that laser scanning can generate a stable gradient temperature field with little influence on the surrounding area. Furthermore, the multi-pass scanning allows for the design of property gradient differential sheets with varying ranges. It is proved that the LHT can effectively improve the plastic strength and the local hardening ability of Al alloy. The results of deep drawing simulations and tests show that the LHT mainly affects the forming ability of differential aluminum alloy sheets by regulating the gradient distribution of strain strengthening n and hardening coefficient k . The gradient decreasing distribution of n value from the heat treatment center to the surrounding area can not only improve the forming ability of the core area, but also alleviate the strain concentration in the periphery, so as to achieve a more uniform strain distribution in the large deformation zone. The gradient distribution of k can change the position and order of the yield behavior of the plate, and then change the material flow sequence, thus slowing down the material flow at the bottom fillet with higher k value and reducing the tendency of thinning and cracking. In particular, it is found that the gradient distribution of k value is the dominant factor to improve the forming ability of poor aluminum alloy sheet. When the gradient of k value distribution between the laser strengthening area and the surrounding material reaches the critical value, the fracture position of the deep drawing part will shift, which greatly delays the occurrence of necking and cracking process and improves the overall forming ability of the sheet. Aluminum alloy Laser heat treatment Formability Multilayer gradient model Deep drawing Full Text Additional Declarations No competing interests reported. Supplementary Files SupplementaryInformation.docx Graphicalabstract.docx Highlight.docx 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-8875960","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":592880815,"identity":"942ef169-7af2-4b3b-be73-825a0c8345df","order_by":0,"name":"Xiao-song Zhang","email":"","orcid":"","institution":"Institute of Metals Research","correspondingAuthor":false,"prefix":"","firstName":"Xiao-song","middleName":"","lastName":"Zhang","suffix":""},{"id":592880816,"identity":"58c94c43-028e-4e8a-ac68-086188bb4e5a","order_by":1,"name":"Shuai-feng Chen","email":"","orcid":"","institution":"Institute of Metals 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drawing","lastPublishedDoi":"10.21203/rs.3.rs-8875960/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8875960/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTo solving the difficulty of forming complex parts of aluminum alloy, a method was proposed using local hardening by laser heat treatment (LHT) to improve the formability of the Al alloy sheet. In order to explore the influence of laser local hardening on deep drawing forming performance, the temperature field of laser treatment was simulated based on the measured data, and a sheet model coupled with mechanical property gradient was established. In addition, the mechanism of the improvement of material formability by the change of constitutive parameters was revealed by the combination of simulation and experiment. The results show that laser scanning can generate a stable gradient temperature field with little influence on the surrounding area. Furthermore, the multi-pass scanning allows for the design of property gradient differential sheets with varying ranges. It is proved that the LHT can effectively improve the plastic strength and the local hardening ability of Al alloy. The results of deep drawing simulations and tests show that the LHT mainly affects the forming ability of differential aluminum alloy sheets by regulating the gradient distribution of strain strengthening \u003cem\u003en\u003c/em\u003e and hardening coefficient \u003cem\u003ek\u003c/em\u003e. The gradient decreasing distribution of \u003cem\u003en\u003c/em\u003e value from the heat treatment center to the surrounding area can not only improve the forming ability of the core area, but also alleviate the strain concentration in the periphery, so as to achieve a more uniform strain distribution in the large deformation zone. The gradient distribution of \u003cem\u003ek\u003c/em\u003e can change the position and order of the yield behavior of the plate, and then change the material flow sequence, thus slowing down the material flow at the bottom fillet with higher \u003cem\u003ek\u003c/em\u003e value and reducing the tendency of thinning and cracking. In particular, it is found that the gradient distribution of \u003cem\u003ek\u003c/em\u003e value is the dominant factor to improve the forming ability of poor aluminum alloy sheet. When the gradient of \u003cem\u003ek\u003c/em\u003e value distribution between the laser strengthening area and the surrounding material reaches the critical value, the fracture position of the deep drawing part will shift, which greatly delays the occurrence of necking and cracking process and improves the overall forming ability of the sheet.\u003c/p\u003e","manuscriptTitle":"Formability Improvement Mechanism of Local Laser Hardened Aluminium Alloy Sheet with Gradient Material Model","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-20 07:58:03","doi":"10.21203/rs.3.rs-8875960/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":"45e51f0b-4a1d-4983-987d-e5bd042c934f","owner":[],"postedDate":"February 20th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-25T20:23:10+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-20 07:58:03","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8875960","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8875960","identity":"rs-8875960","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}