Additive manufacturing最新文献

{"title":"Automated toolpath design of 3D concrete printing structural components","authors":"Yefan Zhi ,&nbsp;Hua Chai ,&nbsp;Teng Teng ,&nbsp;Masoud Akbarzadeh","doi":"10.1016/j.addma.2025.104662","DOIUrl":"10.1016/j.addma.2025.104662","url":null,"abstract":"<div><div>3D concrete printing (3DCP) structural components for construction assemblies are known for reduced material use and enhanced efficiency and design freedom. This article investigates the limitations in the geometrical and toolpath design of 3DCP structural components and presents an automated and comprehensive approach to their toolpath design and optimization. It exploits hierarchical geometric data structures and graph algorithms to achieve the following features: (1) By analyzing the overhang of toolpaths, the method offers quantitative criteria for determining the buildability of the components and predicting failure, thus assisting design decisions. (2) It provides toolpath offsetting and filleting methods that can enhance the dimensional accuracy of the print concerning layer line textures and overfills. (3) For branching and porous geometries, the method creates as-continuous-as-possible toolpaths with minimal stop-starts based on their topologies, thus reducing seam defects. (4) It converts the toolpath into efficient visualization meshes representing layer line textures and toolpath meshes compatible with finite elements analysis. The proposed method is implemented as a plug-in software within the environment of Grasshopper® for Rhino® to facilitate designers and engineers working with 3DCP. The effectiveness and versatility of the tool are demonstrated through the toolpath design and printing of four sets of examples. The tool reduces the number of toolpaths by 90% for a typical 80 mm nozzle and takes 0.21 s per meter of toolpath to slice, analyze overhang, generate continuous printing toolpaths, and visualize the print.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104662"},"PeriodicalIF":10.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crystallization-coalescence relationships in laser powder bed fusion: Moving beyond the “sintering window”","authors":"Camden A. Chatham","doi":"10.1016/j.addma.2025.104668","DOIUrl":"10.1016/j.addma.2025.104668","url":null,"abstract":"<div><div>Laser-based polymer powder bed fusion (PBF-LB/P) additive manufacturing (AM) creates objects through layerwise repetition of selective consolidation of polymer powder particles. The specific molecular- and meso-scale mechanisms responsible for consolidation are important to understand to rapidly identify potential new materials for PBF-LB and correctly attribute observed failures, defects, and deviancy to either feedstock issues or process issues for quality assurance. Such understanding must draw from both material science principles and a deep comprehension of how automated hardware interacts with the feedstock during the manufacturing process. The so-called “Sintering Window” or “PBF Processing Window” is a prevalent tool claimed by many to adequately and rapidly summarize these key relationships between feedstock properties and the manufacturing process. This tool has been common parlance in PBF-LB/P research since the early days of commercialized PBF-LB/P (a.k.a., Selective Laser Sintering, SLS) in the mid 1990’s. The author argues in the present work that lack of progression beyond the rudimentary Sintering Window is hampering advancement of this AM modality as it elevates secondary factors (e.g., crystallization) above primary factors (e.g., coalescence) and does so in a manner disconnected from the real manufacturing environment. The present work outlines four issues with the overuse of the Sintering Window in fundamental research and provides alternative methodologies for reconciling the present body of fundamental polymer science with the present understanding of PBF-LB process physics. Namely, an increased emphasis on coalescing flow behavior that is ultimately arrested by crystallization at the point of physical gelation is recommended for investigating potential suitability of the typical semicrystalline polymer for PBF-LB. Six varieties of nylon-12 and one commercially available polypropylene material are used as exemplars.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104668"},"PeriodicalIF":10.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid prediction and tailoring on compressive behavior of origami-inspired hierarchical structure","authors":"Wenzhen Huang ,&nbsp;Junhong Lin ,&nbsp;Muhong Jiang ,&nbsp;Xiaoli Xu ,&nbsp;Lili Tang ,&nbsp;Xiang Xu ,&nbsp;Yong Zhang","doi":"10.1016/j.addma.2025.104686","DOIUrl":"10.1016/j.addma.2025.104686","url":null,"abstract":"<div><div>Thin-walled structures with tailorable compressive behavior offer a promising solution for achieving desired mechanical properties across multi-scenario applications. Therefore, this paper develops a novel thin-walled structure with high programmability through an origami-inspired hierarchical strategy. The origami-inspired hierarchical structure (OIHS) is fabricated using Laser Powder Bed Fusion. The compressive testing reveals that the deformation of OIHS strictly adheres to the pre-set crease, resulting in a stable load-bearing process. Numerical simulations are further conducted to investigate the programmable capacity of OIHS. The results display that the folding angle <em>θ</em> can enhance the deformation stability of OIHS, but is not conducive to the load-bearing level. The module number <em>M</em> effectively tailors the number and wavelength of folding lobes in OIHS, thus improving the energy absorption and load-bearing stability. As the <em>M</em> increases from 4 to10, the SEA and CFE of OIHS increase by 36.55 % and 17.81 %, respectively. The increasing edge length of sub-cell and wall thickness contribute to the interactive effect and material utilization, respectively, which facilitate its energy absorption. Compared to the vertex-based hierarchical structures, the OIHS demonstrates a 15.78 % increase in load-bearing stability without compromising its energy absorption capacity. Ultimately, artificial neural network-based machine learning models are developed to establish forward and inverse relationships between the mechanical curves and configuration parameters of OIHS, enabling rapid prediction and tailoring of the desired compressive behavior with an error of less than 8 %.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104686"},"PeriodicalIF":10.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nano-scale microstructural evolution and mechanical property enhancement mechanism during crack inhibition in nickel-based superalloys fabricated by laser powder bed fusion","authors":"You Wang ,&nbsp;Wei Guo ,&nbsp;Huaixue Li ,&nbsp;Yinkai Xie ,&nbsp;Jiaxin Shi ,&nbsp;Zhen Liang ,&nbsp;Peipei Han ,&nbsp;Shijian Li ,&nbsp;Hongqiang Zhang","doi":"10.1016/j.addma.2025.104685","DOIUrl":"10.1016/j.addma.2025.104685","url":null,"abstract":"<div><div>Haynes 230, a nickel-based superalloy with a high melting point, is prone to forming microcracks during laser powder bed fusion (LPBF). The correlation between microstructure evolution during crack inhibition and deformation behavior remains unclear. This study compares the microstructure and fracture behavior in both the as-deposited and hot isostatic pressing (HIP) states. After HIP, microcracks closed with the formation of nanoprecipitates at the closure sites, accompanied by increases in both grain and nanoprecipitate sizes, which were limited by pressure. M₂₃C₆ precipitates transformed into M₆C, reducing lattice mismatch. The deformation mechanism in the as-deposited state was dislocation slip, which transitioned to deformation twinning and stacking faults (SFs) after crack inhibition. Importantly, strength and ductility improved synergistically. Strength was enhanced by the combined effects of crack closure and nanoprecipitates hindering dislocation slip, while ductility improved due to crack closure, the formation of nanoprecipitate-induced nanotwins, and the transition in deformation mechanisms. This study elucidates the precipitate transition mechanisms and their role in enhancing mechanical properties.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104685"},"PeriodicalIF":10.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing interfacial toughness of 3D printed bi-material polymers via mechanical interlocking and engineered fiber bridging","authors":"Laia Farràs-Tasias ,&nbsp;Jules Topart ,&nbsp;Stéphane Panier ,&nbsp;Francisco A. Gilabert ,&nbsp;Flávio H. Marchesini","doi":"10.1016/j.addma.2025.104684","DOIUrl":"10.1016/j.addma.2025.104684","url":null,"abstract":"<div><div>Combining materials with distinct properties enables the fabrication of complex structures unattainable with a single material. Hybrid structures, such as those combining stiff and flexible materials, have potential applications in morphing structures, medical prosthetics, and sports goods. The performance of these structures relies heavily on the bonding at the material interface, especially with flat interfaces. Poor bonding can lead to structural failure. This study investigates the bi-material 3D printing of Polylactic Acid (PLA) and Thermoplastic Polyurethane (TPU). PLA is chosen for its environmental friendliness and mechanical properties, while TPU is selected for its flexibility and deformability. The main problem is the weak bonding between PLA and TPU in Fused Filament Fabrication (FFF), often causing failure in the final object. We introduce a methodology to emulate and control the 'fiber bridging' effect occurring in Fiber-Reinforced Polymers (FRP), which enhances interfacial strength. By designing specific patterns and strategically sequencing materials, we create robust mechanical bonds between PLA and TPU. These interface designs significantly increase toughness, improving both bi-directional and unidirectional composites by up to two orders of magnitude. Furthermore, the proposed approach holds potential for application in other multi-material systems, making it a promising strategy for a broader range of material combinations.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104684"},"PeriodicalIF":10.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Process optimization for coaxial extrusion-based bioprinting: A comprehensive analysis of material behavior, structural precision, and cell viability","authors":"Jiarun Sun ,&nbsp;Youping Gong ,&nbsp;Yuchen He ,&nbsp;Chenlong Fan ,&nbsp;Huipeng Chen ,&nbsp;Huifeng Shao ,&nbsp;Rougang Zhou","doi":"10.1016/j.addma.2025.104682","DOIUrl":"10.1016/j.addma.2025.104682","url":null,"abstract":"<div><div>Coaxial extrusion-based bioprinting (CEBB), as a widely applied multimaterial bioprinting technology, demonstrates significant potential in the field of biomanufacturing. However, the fabrication of high-precision hierarchically structured concentric core-shell fibers, while ensuring high cell viability, poses a challenge. Herefore, systematic analysis of the CEBB is mandatory for process optimization concerning production efficiency and printing quality. This paper systematically describes the entire process of CEBB through analytical method, computational fluid dynamics (CFD) and experimental evaluation. Taking pre-crosslinked alginate-collagen bioink as an example, we used gelatin as a sacrificial material to fabricate a double-layered hollow structural scaffold encapsulating human dermal fibroblasts (HDFs) and human umbilical vein endothelial cells (HUVECs). From the rheological behavior of bioink within the coaxial nozzle to the deposition of core-shell strands onto the substrate, we employed mathematical modeling and simulation for analysis, and verified the results against actual prints. A series of characterization tests were conducted to evaluate the impact of material composition and structure on the permeability, mechanical properties, and cell proliferation of the hollow bioscaffold. For potential cell damage during extrusion, we evaluated shear stress and exposure time, both direct influencing factors,which relate to feed volumetric flow rate. Based on the aforementioned research findings, we optimized the printing operation parameters and established encapsulated cell viability, print fidelity and precision, core-shell structural dimensions, and core-shell structural integrity and uniformity as evaluation criteria for CEBB processes. The workflow of systematic analysis and evaluation of CEBB process in this study is applicable to diverse bioinks and coaxial nozzle sizes, effectively reducing time and material costs in the bioengineering industry.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104682"},"PeriodicalIF":10.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143270073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser powder bed fusion printing of compound-eye inspired impedance-matched 3D all-fiber-structured SiC metamaterial for ultra-broadband electromagnetic absorption","authors":"Changshun Wang ,&nbsp;Qingchun Yang ,&nbsp;Huaying You ,&nbsp;Yumeng Hu ,&nbsp;Chunze Yan ,&nbsp;Annan Chen ,&nbsp;Shixiang Zhou ,&nbsp;Guizhou Liu ,&nbsp;Siqi Wu ,&nbsp;Yusheng Shi","doi":"10.1016/j.addma.2025.104665","DOIUrl":"10.1016/j.addma.2025.104665","url":null,"abstract":"<div><div>Silicon carbide (SiC) ceramic-based composites have attracted significant attention for electromagnetic (EM) absorption under extreme environments. However, achieving the balance between impedance matching and attenuation capacity remains an urgent challenge. Inspired by the unique physiological impedance matching and light signal processing characteristics of the compound eye, a synergistic mechanism of macro impedance matching and micro attenuation has been applied to the fabrication of SiC metamaterial absorbers. The excellent impedance matching characteristic was achieved by optimizing the size parameters of frustum pyramid structures. Additionally, the strong intrinsic attenuation capacity was achieved by introducing 3D cross-linked structures constructed by micro/nano SiC fibers. Herein, the compound-eye inspired SiC metamaterial absorber was successfully generated using laser powder bed fusion (LPBF) with an optimized effective absorbing bandwidth (EAB) of 36.06 GHz (3.94−40 GHz) with a printed thickness of 12 mm. The wide-angle absorption was also realized within 0−60° and 0−70° under transverse electric (TE) and transverse magnetic (TM) polarization modes. The compound-eye inspired 3D macro/micro structure integrated strategy provides an efficient approach for the design and fabrication of broadband SiC metamaterial absorbers.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104665"},"PeriodicalIF":10.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards in situ and real time characterization of flow-induced phenomena during material extrusion of polymer composites using 3D X-ray microtomography","authors":"Achille Désiré Betené Omgba ,&nbsp;Lan Zhang ,&nbsp;Florian Martoïa ,&nbsp;Elodie Boller ,&nbsp;Stéphane Pelletreau ,&nbsp;Maxime Dimanche ,&nbsp;Thomas Joffre ,&nbsp;Pierre J.J. Dumont","doi":"10.1016/j.addma.2025.104683","DOIUrl":"10.1016/j.addma.2025.104683","url":null,"abstract":"<div><div>This study investigates the flow-induced phenomena occurring during additive manufacturing by material extrusion of short-fiber reinforced thermoplastic composites. For that purpose, in situ interrupted and real-time printing experiments coupled with 3D synchrotron X-ray microtomography observations were conducted. Various types of composites, namely glass fiber-reinforced polyamide 6, glass-fiber reinforced polycarbonate and wood fiber-reinforced polylactic acid, as well as various nozzles were investigated. Using 3D images acquired during the static printing experiments, it was possible to quantify the evolution of several key microstructure descriptors (e.g., pore and fiber volume fractions, porosity shape and size, fiber length and orientation) in various locations in the tested nozzles. All the experiments revealed that drastic microstructural changes (e.g., pore appearance/disappearance, orientation and shortening of fibers) occurred in various zones of the nozzles during material extrusion. In addition, the results highlighted the central role of the nozzle geometry (e.g., convergent angle, output channel) on the pore formation, transport and disappearance as well as on the orientation and shortening of fibers. Besides, the 3D images acquired during the dynamic (real-time) printing experiments confirmed the observations made during the interrupted tests but also emphasized the complex kinematics of pores in the cavity of the nozzles and the mechanisms at the origin of their disappearance through the convergent. The knowledge acquired during these experiments will undoubtedly lead to the manufacturing of optimized nozzles.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104683"},"PeriodicalIF":10.3,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precipitation behavior and grain growth of Inconel 718 deposited by induction heating-assisted laser directed energy deposition","authors":"Junmyoung Jang ,&nbsp;Yeongcheol Shin ,&nbsp;Juyeong Lee,&nbsp;Seung Hwan Lee","doi":"10.1016/j.addma.2025.104678","DOIUrl":"10.1016/j.addma.2025.104678","url":null,"abstract":"<div><div>This study investigated the precipitation behavior of secondary phases and the grain formation mechanism in Inconel 718 (IN718) prepared by induction heating-assisted laser directed energy deposition (IH-A LDED) depending on the induction heating conditions applied to the deposit. In contrast with conventional LDED, which applies only laser-induced heat during deposition process, the IH-A LDED additionally uses an induction heater to maintain the deposit at a specific temperature. Thus, real-time heat treatment can be implemented during the IH-A LDED process. To compare the secondary phases and grain morphologies formed at different induction heating temperatures, a conventional LDED deposit without induction heating was fabricated, along with three IH-A LDED deposits, which were heated to the temperatures used in the homogenization, solution, and aging heat treatments of IN718. The phase and grain analyses were performed for each deposit, and tensile properties and creep stabilities of each deposit were compared. During the deposition process, two pyrometers were used to measure the temperature profiles, and these data were employed to validate numerical models of the IH-A LDED process. These numerical models were used to derive the hold temperature and hold time and to explain the precipitation behavior of the secondary phases observed in each deposit through the time–temperature–transformation diagram. In addition, solidification parameters depending on the induction heating conditions were derived, and the grain formation mechanism was elucidated.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104678"},"PeriodicalIF":10.3,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct ink writing of coaxial electrostatic fibers with customizable cross-sections and functional properties","authors":"Jingcheng Xiao,&nbsp;Kunlin Wu,&nbsp;Zhiqiang Meng,&nbsp;Junwei Li,&nbsp;Yifan Wang","doi":"10.1016/j.addma.2025.104679","DOIUrl":"10.1016/j.addma.2025.104679","url":null,"abstract":"<div><div>Electrostatic devices have attracted significant interest in recently years, with wide applications in areas such as actuators, sensors, adhesive devices, <em>etc</em>. The common fabrication method of electrostatic devices is through layer-by-layer stacking. However, this process is time-consuming and restricts both design flexibility and performance, presenting a substantial challenge for the rapid development of complex electrostatic systems. To address this problem, we report a method for fabricating coaxial electrostatic fibers (CEFs) using direct ink writing (DIW) method. Silicone-based inks with high conductivity and a high dielectric constant were developed, with their rheological properties optimized for smooth, precise printing. Using these customized inks, electrostatic fiber structures with varying geometries, including one-dimensional fibers, two-dimensional meshes and layered structures, as well as three-dimensional coils and meshes, were successfully manufactured. By modifying the nozzle shape and adjusting the flow rate multiplier, diverse fiber cross-sections and diameters were achieved. The coaxial printing of fiber, layered clutch, and shape morphing devices demonstrated that utilizing highly-dielectric inks and customized cross-sectional geometries significantly improved the device performance. This technique marks a significant advancement in the rapid and efficient fabrication of electrostatic devices, expanding their potential applications in actuators, robotics, haptic interfaces, <em>etc</em>.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104679"},"PeriodicalIF":10.3,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}