{"title":"Mechanisms for pore evolution and heterogeneity in laser powder bed fusion aluminum elucidated through x-ray microscopy","authors":"Daniel R. Sinclair, Nikhilesh Chawla","doi":"10.1016/j.mtla.2025.102358","DOIUrl":null,"url":null,"abstract":"<div><div>Laser powder bed fusion (LPBF) of metallic components produces a unique combination of thermomechanical phenomena such as convection, vaporization, and keyholing. The resulting melt pool structure is not easily characterized in post-facto analysis of printed parts, making process-structure correlations very difficult. Here, structures produced by laser keyhole formation during LPBF of an aerospace aluminum alloy were studied through a simplified sample geometry and controlled remelting. The final distribution of pores within the solidified wall were imaged and quantified through high resolution x-ray microscopy and correlated to the remelted melt pool structure. Based on observations from this multimodal, quantitative analysis, a mechanism for the distribution of porosity is proposed. Novel effects of laser processing conditions on microstructures are thus described, highlighting a key source of heterogeneity across the scales of melt pools to thin 3D features.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"39 ","pages":"Article 102358"},"PeriodicalIF":3.0000,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materialia","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2589152925000250","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Laser powder bed fusion (LPBF) of metallic components produces a unique combination of thermomechanical phenomena such as convection, vaporization, and keyholing. The resulting melt pool structure is not easily characterized in post-facto analysis of printed parts, making process-structure correlations very difficult. Here, structures produced by laser keyhole formation during LPBF of an aerospace aluminum alloy were studied through a simplified sample geometry and controlled remelting. The final distribution of pores within the solidified wall were imaged and quantified through high resolution x-ray microscopy and correlated to the remelted melt pool structure. Based on observations from this multimodal, quantitative analysis, a mechanism for the distribution of porosity is proposed. Novel effects of laser processing conditions on microstructures are thus described, highlighting a key source of heterogeneity across the scales of melt pools to thin 3D features.
期刊介绍:
Materialia is a multidisciplinary journal of materials science and engineering that publishes original peer-reviewed research articles. Articles in Materialia advance the understanding of the relationship between processing, structure, property, and function of materials.
Materialia publishes full-length research articles, review articles, and letters (short communications). In addition to receiving direct submissions, Materialia also accepts transfers from Acta Materialia, Inc. partner journals. Materialia offers authors the choice to publish on an open access model (with author fee), or on a subscription model (with no author fee).