Advanced Nickel Superalloy Printing with Ring-Based LBPF

Advanced Nickel Superalloy Printing with Ring-Based LBPF | 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 Advanced Nickel Superalloy Printing with Ring-Based LBPF Austin Tiley, Joe Walker, John Middendorf This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9452780/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract In additive manufacturing (AM), Beam shaping is gaining interest in adoption to increase overall productivity. However, a lack of investigation on the microstructural and material response of beam shaping has been publicized. Further, beam shaping has unique thermal inputs that show potential for fabricating components of previously unwieldable Nickel Superalloys through laser powder bed fusion (LPBF). High γ’ Nickel Superalloys are an ideal candidate for this evaluation due to their difficulties during fabrication, post-processing, and implementation into production environments. These alloys are attractive due to their material and mechanical properties at elevated temperatures that exceed common commercial alloys such as IN718. This experimental study investigates the feasibility of processing IN939, a γ’ superalloy, through Ring lasers utilizing an nLight AFX multi-mode laser. The outcome of this study is an understanding of necessary processing parameters to produce an acceptable bulk sample. Results include ideal print parameters, density analysis, and provide insight in future printing. Ring laser Laser Powder Bed Fusion Beam Shaping Solidification Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 1. Introduction Laser powder bed fusion (LPBF) is an attractive additive manufacturing (AM) process for producing nickel superalloy components due to near-net shape capability and amount of user control [ 1 ]. Given the process of adoption for new technology, LPBF has historically focused on weldable nickel superalloys such as IN718 or IN625, both γ’’ superalloys [ 2 ]. Although production of high γ’ nickel superalloys is attractive for elevated thermos-mechanical properties and potential creep improvement over wrought, adoption is limited due to defects within the printed microstructure [ 2 ]. While AM defects such as porosity and lack of fusion voids are present in these alloys, the γ/γ’ relationship alongside alloy segregation make cracking more susceptible [ 3 ]. Cracking causes premature mechanical failure leading to rejection of high-volume fraction γ’ alloys for LBPF. An example of solidification in Nickel Alloys is shown in Fig. 1 [ 4 ]. LPBF systems integrate a reservoir of material that is moved to a substrate for welding. The material surface is then melted on a layer-by-layer basis by a laser heat source. Processing in layers can result in epitaxial microstructural growth and anisotropic properties. Traditional LPBF systems use Gaussian beams as a heat source, which have a laser beam profiles that includes high concentrations of energy at the center of the beam and a drop-off in energy towards the edges. To combat the economic disadvantage of the powder bed design, namely long processing time, industry is evaluating alternative beam shapes to improve processing productivity [ 5 ]. By leveraging different beam shapes and their resultant thermal gradients, parts can be produced faster. Melt pool geometry plays a major role in this productivity gain, with wider melt pools requiring less passes to complete a weld. The overall heat input to the material can be further manipulated by the pre or post heating, scan strategies, or geometry optimization. Controlling the overall laser heat input allows for crack mitigation of γ’ nickel superalloys by manipulating the thermal gradient and solidification rate to specific solidification modes. As advanced beam shaping control units are integrated into laser-based AM systems to optimize material processing, characterization of cracking mechanisms impacted by this technology must be conducted to evaluate feasibility of industry adoption. LPBF components fabricated out of γ’ nickel superalloys experience high stresses and strains during processing which are known to promote solidification cracking [ 6 ]. Because these stress and strain values are cost prohibitive and computationally difficult to quantify during the printing process, post-weld inspection are typically performed to evaluate cracking. In addition, the high thermal gradient created by gaussian laser heat sources promote alloy segregation, thus widening the solidification temperature range (STR) and increasing solidification crack susceptibility. Thus, a need to understand the characteristics of materials produced by these alternative heat sources becomes apparent for complete characterization of the AM welds. Individual models for solidification cracking, strain evolution during processing, and melt pool dynamics were previously developed independently, resulting in a lack of cohesion [ 7 ]. To use these models, a informative database needs to be accessible for beam shaping results. Aerospace and defense industries have identified nickel superalloy IN939 as a representative alloy of interest due to the material properties in extreme environments. As a strengthening phase, γ’ is ideal for elevated temperature applications and is coherent with γ providing ductility. IN939 has significant amounts of Al + Ti (> 5 wt.%) for γ’ precipitation, as well as other alloys such as W and Co that are notorious for weld cracking issues that if resolved will transfer to other γ’ nickel superalloys [ 8 ]. 2. Methodology To evaluate the impact of beam shaping an AMCM M290 Flex was used as the LPBF system. The M290 Flex is equipped with an nLight AFX-1200W laser that can switch between 7 different beam modes (Fig. 2 ). A carbon steel build plate was utilized as the substrate with a soft rubber recoater. To provide a thorough understanding of a beam shaped effect, the Ring profile (mode 6) was selected as this profile differs the most from a standard Gaussian profile (mode 0). A Ring laser profile has roughly 10% of the intensity in the center of the beam and 90% of intensity on the outer edge vs Gaussian’s concentrated intensity at the center of the beam. OEM parameters exist for IN939 utilizing a Gaussian profile, however after consultation with CDME partners, these parameters were deemed not viable for industrial use. A widespread parameter experiment (Table 1 ) was developed to ensure beam effects were accurately captured. All samples were built using only bulk parameters. Volumetric Energy Density (VED) was not a factor in development of the DOE as it does not account for the intensity profile of the laser spot. However, as the VED equation is currently widely used in typical gaussian processing, it can be used as a qualitative descriptor when analyzing results. The VED is commonly given as: \(\:VED=\:\frac{P}{Vht}\) Eq. (1) Where P is power (W), V is scanning speed (mm/s), h is hatch (mm), and t is layer thickness (mm). Table 1 Design of Experiments Parameters for Ring Profile | (OEM Gaussian) Parameter Values Layer Thickness (mm) 0.08 | (0.04) Power (W) 450, 500, 550, 600, 650, 700 | (265) Speed (mm/s) 1100, 1200, 1300, 1400, 1500, 1600 | (1300) Hatch (mm) 0.14, 0.16, 0.18, 0.2 | (0.07) IN939 spherical powder was obtained through Linde AMT with a particle size distribution of 15–45 microns. This powder was mount in a fast-curing resin-epoxy mixture and then rough ground to 800 grit. This grinding step will ensure that chemical analysis will be conducted inside the poweder, as well as, evaluate if there are any initial internal porosities. Energy Dispersive Spectroscopy (EDS) was utilized to measure the chemical composition of the powder. Multiple powder sites were analyzed and averaged to provide a wholistic chemical composition (Table 2 ). This composition was determined to be acceptable for IN939 [ 2 ]. Table 2 Chemical composition of powder through EDS. Element Wt% C 7.846 Al 1.758 Ti 3.716 Cr 20.87 Co 17.31 Ni 43.77 Nb 0.968 Ta 1.598 W 2.168 Typically γ’ alloys will undergo a heat treatment after AM fabrication to obtain desired phase propagation. As this effort was focused on defect production during the printing process, a heat treatment was not conducted on the samples. Samples were designed with a tapered wedge to be removed manually once the plate reached room temp. After removal, samples were mounted in thermosetting, bakelite resin with carbon filler (PolyFast). Samples were then ground using 5 lb-f at grits starting from 180 grit to 1100 grit. A cleaning step of water and alcohol was conducted between each step. Polishing was conducted using 5lb-f for 9 micron, 3 micron, 1 micron, and colloidal silica. All polishing agents were water based to ensure full removal of the polish before continuing to the next step. Samples were then imaged using a KEYENCE VHX-X1 at 12.5x up to 200x. Images were then processed using a MATLAB script to ensure uniform thresholding of pixels. After thresholding, density was then calculated. For high density samples (> 99.5%), advanced imaging was performed on a Thermo Scientific Apreo Scanning Electron Microscope (SEM). 3. Results Accounting for pre- and post-preparation, the build was printed over the course of a day and allowed to cool overnight. Labels were printed directly on the samples using the corresponding parameter for that sample. Visually, no major defects were detected on the outside of any sample (Fig. 4 ). A qualitive surface skin quality could be roughly linked to energy density, where higher volumetric energy density samples exhibited more surface shine compared to a duller shine for low volumetric energy density (VED). Six representative samples were selected for initial metallography based off the geometric extremes of the print. The parameters for these samples can be found in Table 3 . Initial qualitative visual inspection anticipated sample 89 to have acceptable density with sample 67 to have a better contour. Table 3 Parameters for the 6 representative DOE samples. Sample Power (W) Speed (mm/s) Hatch (mm) Layer thickness (mm) Energy density (J/mm^3) 2 500 1100 0.14 0.08 40.58 11 650 1100 0.16 0.08 46.16 67 450 1600 0.16 0.08 21.97 89 650 1200 0.18 0.08 37.62 135 500 1600 0.18 0.08 21.70 142 600 1600 0.2 0.08 23.44 Metallography revealed that < 30 VED samples showed significant lack of fusion defects visible to the eye. Additionally, samples 1–12 appear to have the least amount of defects. This could be do to the higher energy input or location on the plate. These samples were closest to the exhaust of the cross bed flow and were printed first in the exposure order, thus making them less susceptible to detrimental spatter effects. Figure 5 shows the representative 6 samples and their corresponding density regions of interest. Samples 2 and 11 were the only samples with an acceptable density near or above 99.5% (Table 4 ). Table 4 Density of Representative Samples Sample VED (J/mm^3) Density (%) 2 40.58 99.57 11 46.16 99.49 67 21.97 67.29 89 37.62 93.38 135 23.87 54.93 142 27.34 53.56 Due to a lack of large voids, Sample 11 was taken to an SEM for Secondary Electron (SE) and Back Scatter Electron (BSE) imaging. This imaging revealed the presence of small microcracks within the bulk region (Fig. 6 ). From imaging, these microcracks resemble solidification cracks due to their alignment along grain boundaries and the interior dendrite morphology. Understanding the crack type will help inform the correct processing conditions for future builds. It is vital to understand how the microcracks form as Nickel Superalloys go through strenuous heat treatment conditions and are also susceptible to cracking during this process. If the crack is forming during the printing process, it will likely propagate or lead to premature failure during post-process heating. 4. Conclusion Beam shaping was successfully demonstrated to produce high density samples for IN939. A suite of parameters was shown to print successfully without the need for termination of any sample. Results show a trend of higher energy input, seeming to improve overall bulk density. A sample was produced free of major voids such as lack of fusion or porosity. By evaluating the change in layer thickness (doubling from gaussian to ring), it is anticipated that samples can be produced much faster using beam shaping. The presence of microcracks indicates that these parameters need to be refined. Further investigation may include: refined analysis of crack initiation, processing response of alternative beam shapes, and studying the increase in productivity allowed by beam shaping. Declarations The authors declare that no funds, grants, or other support were received during preparation of this manuscript. The authors have no relevant financial or non-financial interests to declare. Author contributions are as follows: Austin Tiley : Methodology, Formal analysis, Metallography, Data Curation, Writing – Original Draft, Writing – Review and Editing Joe Walker : Investigation, Writing – Review and Editing John Middendorf : Writing – Review and Editing, Supervision Acknowledgements The authors would like to thank Siemens Energy for their donation of IN939 powder. Partial funding for this work was provided from Manufacturing & Materials Joining Innovation Center (Ma 2 JIC), sponsored by U.S. National Science Foundation Industry University Cooperative Research Center Program in the form of an NSF-INTERN supplement. Author contributions are as follows: References Weibach R (2024) Scaling Metal Additive Manufacturing from R&D to Production. Massachusetts Institute of Technology, Munich Adegoke O, Andersson J, Brodin H, Pederson R (2020) Review of Laser Powder Bed Fusion of Gamma-Prime-Strengthened Nickel-Based Superalloys. Metals Raghu R, Chandramohan D, K. P. and, Singh A (2023) Structural Characterization and Strength Assessment of Laser Powder Bed Fusion Manufactured CM247LC Nickel Based Super Alloy. J Mater Eng Perform, 32, 24 Lippold J (2015) Failure Analysis. Welding Metallurgy and Weldability. John Wiley & Sons, Inc., Hoboken, p 321 Grunewald J, Gehringer F, Schmoller M, Wudy K (2021) Influence of Ring-Shaped Beam Profiles on Process Stability and Productivity in Laser-Based Powder Bed Fusion of AISI 316L. Metals Yan Z, Weiwei L, Tang Z, Liu X, Zhang N, Li M, Zhang H (2018) Review on thermal analysis in laser-based additive manufacturing. Opt Laser Technol 106:427–441 Hekmatjou H, Zeng Z, Shen J, Oliveira J, Naffakh-Moosavy H (2020) A Comparative Study of Analytical Rosenthal, Finite Element, and Experimental Approaches in Laser Welding of AA5456 Alloy, metals , vol. 10, no. 436, pp. 1–25 Tang Y, Panwisawas C, Ghoussoub J, Gong Y, Clark J, Nemeth A, McCartney D, Reed R (2021) Alloys-by-design: Application to new superalloys for additive manufacturing. Acta Mater no 202:417–436 Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 09 May, 2026 Reviewers invited by journal 05 May, 2026 Editor assigned by journal 05 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. 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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-9452780","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":634824885,"identity":"6533b107-e9ea-4085-8614-659a7d482cf4","order_by":0,"name":"Austin Tiley","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvElEQVRIiWNgGAWjYDACZuYGIPlPDsJjI0IHDzMjSMsBYxK0MEC0JDYQrcWenbHxMQ/DnfR+/jMGDB/KDhPlsGZjHoZnuTNn5BgwzjhHnJY2aR4G5twNN3gMmHnbiNPS/huoJd3g/BkD5r9Eamlj5mE4nGBwIMcAyCZGy2HGZsk5BmmGM2ekFRzsOZdOWAt7/+GDH95U2Mjz8x/e+OBHmTVhLSDAxGMAYRwgTj0QMP4gWukoGAWjYBSMSAAAjOkzqQbXPGoAAAAASUVORK5CYII=","orcid":"https://orcid.org/0009-0007-6609-0722","institution":"The Ohio State University College of Engineering","correspondingAuthor":true,"prefix":"","firstName":"Austin","middleName":"","lastName":"Tiley","suffix":""},{"id":634824886,"identity":"479df395-6d10-4539-9fe4-d9fa2a02d534","order_by":1,"name":"Joe Walker","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Joe","middleName":"","lastName":"Walker","suffix":""},{"id":634824887,"identity":"2a5974c1-b5ce-4a1b-bab1-8c4a4873f94c","order_by":2,"name":"John Middendorf","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"John","middleName":"","lastName":"Middendorf","suffix":""}],"badges":[],"createdAt":"2026-04-17 21:31:36","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9452780/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9452780/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109283710,"identity":"3d769ea5-6627-44ba-9dfb-baa8b9bfb8e4","added_by":"auto","created_at":"2026-05-14 19:55:48","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":367260,"visible":true,"origin":"","legend":"\u003cp\u003e\"Egg-crate\" morphology of a solidification crack in a high Cr, Ni alloy captured in an SEM image. Rounded dendrites indicate presence of liquid and are representative of solidification cracking [4].\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-9452780/v1/9d668a6f6386b1015292e2e4.png"},{"id":109283711,"identity":"2bacdf93-5c3d-47cd-87c5-3d265f21b849","added_by":"auto","created_at":"2026-05-14 19:55:48","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":51183,"visible":true,"origin":"","legend":"\u003cp\u003eDifferent beam shapes that the AFX-1200 is capable of (courtesy nLight).\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-9452780/v1/8a889a66f90ba617085b924b.png"},{"id":109283716,"identity":"cb2e6454-34d6-4707-b53f-3489083a250b","added_by":"auto","created_at":"2026-05-14 19:55:49","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":370241,"visible":true,"origin":"","legend":"\u003cp\u003eEDS locations of powder. Multiple sites were evaluated to generate an average composition.\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-9452780/v1/019126df75c57c70b80d8dd0.png"},{"id":109296338,"identity":"db8b4f2c-0fa4-41e8-bc37-1fb2bc776ded","added_by":"auto","created_at":"2026-05-15 08:46:32","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":754936,"visible":true,"origin":"","legend":"\u003cp\u003eDOE for the Ring profile after printing. Each quadrant corresponds to a different hatch profile: Bottom Left – 0.14 mm, Bottom Right – 0.16 mm, Top Left – 0.18, Top Right – 0.2 mm.\u003c/p\u003e","description":"","filename":"image4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9452780/v1/cf6c7e2fc5029dd5949fc0f6.jpeg"},{"id":109296357,"identity":"17b9e625-e0ba-452b-b415-b663a4f50eff","added_by":"auto","created_at":"2026-05-15 08:46:37","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":982714,"visible":true,"origin":"","legend":"\u003cp\u003eDensity profiles of extremes of the plate with two samples (67, 89) taken from the middle.\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-9452780/v1/c9e7c0ac6cd311abcdddcf97.png"},{"id":109283714,"identity":"678aa63a-0003-40be-bf50-72594eab32f5","added_by":"auto","created_at":"2026-05-14 19:55:48","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":722739,"visible":true,"origin":"","legend":"\u003cp\u003eImaging showing interior crack morphology (Left). Crack appears to propagate along grain boundary (Right).\u003c/p\u003e","description":"","filename":"image6.png","url":"https://assets-eu.researchsquare.com/files/rs-9452780/v1/75e1a8029f54d573b69596b7.png"}],"financialInterests":"","formattedTitle":"Advanced Nickel Superalloy Printing with Ring-Based LBPF","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eLaser powder bed fusion (LPBF) is an attractive additive manufacturing (AM) process for producing nickel superalloy components due to near-net shape capability and amount of user control [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Given the process of adoption for new technology, LPBF has historically focused on weldable nickel superalloys such as IN718 or IN625, both γ\u0026rsquo;\u0026rsquo; superalloys [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Although production of high γ\u0026rsquo; nickel superalloys is attractive for elevated thermos-mechanical properties and potential creep improvement over wrought, adoption is limited due to defects within the printed microstructure [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. While AM defects such as porosity and lack of fusion voids are present in these alloys, the γ/γ\u0026rsquo; relationship alongside alloy segregation make cracking more susceptible [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Cracking causes premature mechanical failure leading to rejection of high-volume fraction γ\u0026rsquo; alloys for LBPF. An example of solidification in Nickel Alloys is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eLPBF systems integrate a reservoir of material that is moved to a substrate for welding. The material surface is then melted on a layer-by-layer basis by a laser heat source. Processing in layers can result in epitaxial microstructural growth and anisotropic properties. Traditional LPBF systems use Gaussian beams as a heat source, which have a laser beam profiles that includes high concentrations of energy at the center of the beam and a drop-off in energy towards the edges. To combat the economic disadvantage of the powder bed design, namely long processing time, industry is evaluating alternative beam shapes to improve processing productivity [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. By leveraging different beam shapes and their resultant thermal gradients, parts can be produced faster. Melt pool geometry plays a major role in this productivity gain, with wider melt pools requiring less passes to complete a weld. The overall heat input to the material can be further manipulated by the pre or post heating, scan strategies, or geometry optimization. Controlling the overall laser heat input allows for crack mitigation of γ\u0026rsquo; nickel superalloys by manipulating the thermal gradient and solidification rate to specific solidification modes.\u003c/p\u003e \u003cp\u003eAs advanced beam shaping control units are integrated into laser-based AM systems to optimize material processing, characterization of cracking mechanisms impacted by this technology must be conducted to evaluate feasibility of industry adoption. LPBF components fabricated out of γ\u0026rsquo; nickel superalloys experience high stresses and strains during processing which are known to promote solidification cracking [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Because these stress and strain values are cost prohibitive and computationally difficult to quantify during the printing process, post-weld inspection are typically performed to evaluate cracking. In addition, the high thermal gradient created by gaussian laser heat sources promote alloy segregation, thus widening the solidification temperature range (STR) and increasing solidification crack susceptibility.\u003c/p\u003e \u003cp\u003eThus, a need to understand the characteristics of materials produced by these alternative heat sources becomes apparent for complete characterization of the AM welds. Individual models for solidification cracking, strain evolution during processing, and melt pool dynamics were previously developed independently, resulting in a lack of cohesion [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. To use these models, a informative database needs to be accessible for beam shaping results. Aerospace and defense industries have identified nickel superalloy IN939 as a representative alloy of interest due to the material properties in extreme environments. As a strengthening phase, γ\u0026rsquo; is ideal for elevated temperature applications and is coherent with γ providing ductility. IN939 has significant amounts of Al\u0026thinsp;+\u0026thinsp;Ti (\u0026gt;\u0026thinsp;5 wt.%) for γ\u0026rsquo; precipitation, as well as other alloys such as W and Co that are notorious for weld cracking issues that if resolved will transfer to other γ\u0026rsquo; nickel superalloys [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e"},{"header":"2. Methodology","content":"\u003cp\u003eTo evaluate the impact of beam shaping an AMCM M290 Flex was used as the LPBF system. The M290 Flex is equipped with an nLight AFX-1200W laser that can switch between 7 different beam modes (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). A carbon steel build plate was utilized as the substrate with a soft rubber recoater. To provide a thorough understanding of a beam shaped effect, the Ring profile (mode 6) was selected as this profile differs the most from a standard Gaussian profile (mode 0). A Ring laser profile has roughly 10% of the intensity in the center of the beam and 90% of intensity on the outer edge vs Gaussian\u0026rsquo;s concentrated intensity at the center of the beam. OEM parameters exist for IN939 utilizing a Gaussian profile, however after consultation with CDME partners, these parameters were deemed not viable for industrial use. A widespread parameter experiment (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) was developed to ensure beam effects were accurately captured. All samples were built using only bulk parameters. Volumetric Energy Density (VED) was not a factor in development of the DOE as it does not account for the intensity profile of the laser spot. However, as the VED equation is currently widely used in typical gaussian processing, it can be used as a qualitative descriptor when analyzing results. The VED is commonly given as:\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003e \u003cspan class=\"InlineEquation\"\u003e \u003cspan class=\"mathinline\"\u003e\\(\\:VED=\\:\\frac{P}{Vht}\\)\u003c/span\u003e \u003c/span\u003e Eq.\u0026nbsp;(1)\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eWhere \u003cem\u003eP\u003c/em\u003e is power (W), \u003cem\u003eV\u003c/em\u003e is scanning speed (mm/s), \u003cem\u003eh\u003c/em\u003e is hatch (mm), and \u003cem\u003et\u003c/em\u003e is layer thickness (mm).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDesign of Experiments Parameters for Ring Profile | \u003cb\u003e(OEM Gaussian)\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eValues\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLayer Thickness (mm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.08 | \u003cb\u003e(0.04)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePower (W)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e450, 500, 550, 600, 650, 700 | \u003cb\u003e(265)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpeed (mm/s)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1100, 1200, 1300, 1400, 1500, 1600 | \u003cb\u003e(1300)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHatch (mm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.14, 0.16, 0.18, 0.2 | \u003cb\u003e(0.07)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIN939 spherical powder was obtained through Linde AMT with a particle size distribution of 15\u0026ndash;45 microns. This powder was mount in a fast-curing resin-epoxy mixture and then rough ground to 800 grit. This grinding step will ensure that chemical analysis will be conducted inside the poweder, as well as, evaluate if there are any initial internal porosities. Energy Dispersive Spectroscopy (EDS) was utilized to measure the chemical composition of the powder. Multiple powder sites were analyzed and averaged to provide a wholistic chemical composition (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). This composition was determined to be acceptable for IN939 [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eChemical composition of powder through EDS.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eElement\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWt%\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7.846\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.758\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTi\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.716\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20.87\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e17.31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNi\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e43.77\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.968\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTa\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.598\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eW\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.168\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTypically γ\u0026rsquo; alloys will undergo a heat treatment after AM fabrication to obtain desired phase propagation. As this effort was focused on defect production during the printing process, a heat treatment was not conducted on the samples. Samples were designed with a tapered wedge to be removed manually once the plate reached room temp.\u003c/p\u003e \u003cp\u003eAfter removal, samples were mounted in thermosetting, bakelite resin with carbon filler (PolyFast). Samples were then ground using 5 lb-f at grits starting from 180 grit to 1100 grit. A cleaning step of water and alcohol was conducted between each step. Polishing was conducted using 5lb-f for 9 micron, 3 micron, 1 micron, and colloidal silica. All polishing agents were water based to ensure full removal of the polish before continuing to the next step.\u003c/p\u003e \u003cp\u003eSamples were then imaged using a KEYENCE VHX-X1 at 12.5x up to 200x. Images were then processed using a MATLAB script to ensure uniform thresholding of pixels. After thresholding, density was then calculated. For high density samples (\u0026gt;\u0026thinsp;99.5%), advanced imaging was performed on a Thermo Scientific Apreo Scanning Electron Microscope (SEM).\u003c/p\u003e"},{"header":"3. Results","content":"\u003cp\u003eAccounting for pre- and post-preparation, the build was printed over the course of a day and allowed to cool overnight. Labels were printed directly on the samples using the corresponding parameter for that sample. Visually, no major defects were detected on the outside of any sample (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eA qualitive surface skin quality could be roughly linked to energy density, where higher volumetric energy density samples exhibited more surface shine compared to a duller shine for low volumetric energy density (VED). Six representative samples were selected for initial metallography based off the geometric extremes of the print. The parameters for these samples can be found in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Initial qualitative visual inspection anticipated sample 89 to have acceptable density with sample 67 to have a better contour.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eParameters for the 6 representative DOE samples.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePower\u003c/p\u003e \u003cp\u003e(W)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSpeed\u003c/p\u003e \u003cp\u003e(mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eHatch\u003c/p\u003e \u003cp\u003e(mm)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLayer thickness\u003c/p\u003e \u003cp\u003e(mm)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eEnergy density\u003c/p\u003e \u003cp\u003e(J/mm^3)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003e2\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e40.58\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003e11\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e650\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e46.16\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003e67\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e450\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e21.97\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003e89\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e650\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e37.62\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003e135\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e21.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003e142\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e23.44\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eMetallography revealed that \u0026lt;\u0026thinsp;30 VED samples showed significant lack of fusion defects visible to the eye. Additionally, samples 1\u0026ndash;12 appear to have the least amount of defects. This could be do to the higher energy input or location on the plate. These samples were closest to the exhaust of the cross bed flow and were printed first in the exposure order, thus making them less susceptible to detrimental spatter effects. Figure\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e shows the representative 6 samples and their corresponding density regions of interest. Samples 2 and 11 were the only samples with an acceptable density near or above 99.5% (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDensity of Representative Samples\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVED (J/mm^3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDensity (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e99.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e46.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e99.49\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e67.29\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e37.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e93.38\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e135\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e23.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e54.93\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e142\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e27.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e53.56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eDue to a lack of large voids, Sample 11 was taken to an SEM for Secondary Electron (SE) and Back Scatter Electron (BSE) imaging. This imaging revealed the presence of small microcracks within the bulk region (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). From imaging, these microcracks resemble solidification cracks due to their alignment along grain boundaries and the interior dendrite morphology. Understanding the crack type will help inform the correct processing conditions for future builds. It is vital to understand how the microcracks form as Nickel Superalloys go through strenuous heat treatment conditions and are also susceptible to cracking during this process. If the crack is forming during the printing process, it will likely propagate or lead to premature failure during post-process heating.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eBeam shaping was successfully demonstrated to produce high density samples for IN939. A suite of parameters was shown to print successfully without the need for termination of any sample. Results show a trend of higher energy input, seeming to improve overall bulk density. A sample was produced free of major voids such as lack of fusion or porosity. By evaluating the change in layer thickness (doubling from gaussian to ring), it is anticipated that samples can be produced much faster using beam shaping. The presence of microcracks indicates that these parameters need to be refined. Further investigation may include: refined analysis of crack initiation, processing response of alternative beam shapes, and studying the increase in productivity allowed by beam shaping.\u003c/p\u003e"},{"header":"Declarations","content":"\u003col start=\"2\" style=\"list-style-type: lower-alpha;\"\u003e\n \u003cli\u003eThe authors declare that no funds, grants, or other support were received during preparation of this manuscript.\u003c/li\u003e\n \u003cli\u003eThe authors have no relevant financial or non-financial interests to declare.\u003c/li\u003e\n \u003cli\u003eAuthor contributions are as follows:\u003col style=\"list-style-type: lower-alpha;\"\u003e\n \u003cli\u003e\u003cstrong\u003eAustin Tiley\u003c/strong\u003e: Methodology, Formal analysis, Metallography, Data Curation, Writing \u0026ndash; Original Draft, Writing \u0026ndash; Review and Editing\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eJoe Walker\u003c/strong\u003e: Investigation, Writing \u0026ndash; Review and Editing\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eJohn Middendorf\u003c/strong\u003e: Writing \u0026ndash; Review and Editing, Supervision\u003c/li\u003e\n \u003c/ol\u003e\n \u003c/li\u003e\n\u003c/ol\u003e\n\u003ch1\u003eAcknowledgements\u003c/h1\u003e\n\u003cp\u003eThe authors would like to thank Siemens Energy for their donation of IN939 powder. Partial funding for this work was provided from Manufacturing \u0026amp; Materials Joining Innovation Center (Ma\u003csup\u003e2\u003c/sup\u003eJIC), sponsored by U.S. National Science Foundation Industry University Cooperative Research Center Program in the form of an NSF-INTERN supplement.\u003c/p\u003e\u003ch2\u003eAuthor contributions\u003c/h2\u003e \u003cp\u003eare as follows:\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWeibach R (2024) Scaling Metal Additive Manufacturing from R\u0026amp;D to Production. Massachusetts Institute of Technology, Munich\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAdegoke O, Andersson J, Brodin H, Pederson R (2020) Review of Laser Powder Bed Fusion of Gamma-Prime-Strengthened Nickel-Based Superalloys. Metals\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRaghu R, Chandramohan D, K. P. and, Singh A (2023) Structural Characterization and Strength Assessment of Laser Powder Bed Fusion Manufactured CM247LC Nickel Based Super Alloy. J Mater Eng Perform, 32, 24\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLippold J (2015) Failure Analysis. Welding Metallurgy and Weldability. John Wiley \u0026amp; Sons, Inc., Hoboken, p 321\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrunewald J, Gehringer F, Schmoller M, Wudy K (2021) Influence of Ring-Shaped Beam Profiles on Process Stability and Productivity in Laser-Based Powder Bed Fusion of AISI 316L. Metals\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYan Z, Weiwei L, Tang Z, Liu X, Zhang N, Li M, Zhang H (2018) Review on thermal analysis in laser-based additive manufacturing. Opt Laser Technol 106:427\u0026ndash;441\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHekmatjou H, Zeng Z, Shen J, Oliveira J, Naffakh-Moosavy H (2020) A Comparative Study of Analytical Rosenthal, Finite Element, and Experimental Approaches in Laser Welding of AA5456 Alloy, \u003cem\u003emetals\u003c/em\u003e, vol. 10, no. 436, pp. 1\u0026ndash;25\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTang Y, Panwisawas C, Ghoussoub J, Gong Y, Clark J, Nemeth A, McCartney D, Reed R (2021) Alloys-by-design: Application to new superalloys for additive manufacturing. Acta Mater no 202:417\u0026ndash;436\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":false,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"the-international-journal-of-advanced-manufacturing-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jamt","sideBox":"Learn more about [The International Journal of Advanced Manufacturing Technology](https://www.springer.com/journal/170)","snPcode":"170","submissionUrl":"https://submission.nature.com/new-submission/170/3","title":"The International Journal of Advanced Manufacturing Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Ring laser, Laser Powder Bed Fusion, Beam Shaping, Solidification","lastPublishedDoi":"10.21203/rs.3.rs-9452780/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9452780/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn additive manufacturing (AM), Beam shaping is gaining interest in adoption to increase overall productivity. However, a lack of investigation on the microstructural and material response of beam shaping has been publicized. Further, beam shaping has unique thermal inputs that show potential for fabricating components of previously unwieldable Nickel Superalloys through laser powder bed fusion (LPBF). High γ\u0026rsquo; Nickel Superalloys are an ideal candidate for this evaluation due to their difficulties during fabrication, post-processing, and implementation into production environments. These alloys are attractive due to their material and mechanical properties at elevated temperatures that exceed common commercial alloys such as IN718. This experimental study investigates the feasibility of processing IN939, a γ\u0026rsquo; superalloy, through Ring lasers utilizing an nLight AFX multi-mode laser. The outcome of this study is an understanding of necessary processing parameters to produce an acceptable bulk sample. Results include ideal print parameters, density analysis, and provide insight in future printing.\u003c/p\u003e","manuscriptTitle":"Advanced Nickel Superalloy Printing with Ring-Based LBPF","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-14 19:55:44","doi":"10.21203/rs.3.rs-9452780/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2026-05-09T21:51:48+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-05-05T12:57:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-05-05T06:09:28+00:00","index":"","fulltext":""},{"type":"submitted","content":"The International Journal of Advanced Manufacturing Technology","date":"2026-05-01T08:53:11+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"the-international-journal-of-advanced-manufacturing-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jamt","sideBox":"Learn more about [The International Journal of Advanced Manufacturing Technology](https://www.springer.com/journal/170)","snPcode":"170","submissionUrl":"https://submission.nature.com/new-submission/170/3","title":"The International Journal of Advanced Manufacturing Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"33bcdf38-47a5-483e-b54f-775afdc648bb","owner":[],"postedDate":"May 14th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"","date":"2026-05-09T21:51:48+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-05-05T12:57:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-05-05T06:09:28+00:00","index":"","fulltext":""},{"type":"submitted","content":"The International Journal of Advanced Manufacturing Technology","date":"2026-05-01T08:53:11+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-14T19:55:44+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-14 19:55:44","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9452780","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9452780","identity":"rs-9452780","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}